This is also on another forum.

Let me start out with an argument and please keep in mind I do this for a living. I have first hand experience and I am GM certified.
TimeSerts are a band aid and just make the bolt bigger in this case. Yes They just make the bolt bigger. This is a fact. They do not become a part of the block.

I have seen TimeSert inserts lock into an aluminum part, but that is not the case with the Northstar head bolt application.

If you have a brand new block. You removed the heads, then installed Timeserts, and then reinstalled the heads you may have just caused a premature failure. Just say the engine goes 80K and looses a head gasket for another reason (ran low on coolant) now when you remove the head bolts the inserts come out (this is typical) now what? GM doe not endorse any large or big inserts

This how they come out
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/timesertonbolt.jpg

This is a TimeSert insert If you notice it does NOT have a flange at the top or just a minor flange to seat it in place
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/headtimesert.jpg

This is a Norms insert. This will be another part of this discussion later.
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/norms.jpg

This is the two of them side by side
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/NormsVStimsert.jpg

http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/TimesertvsNorms.jpg

http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/timesertvsnorms3.jpg

http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/Timesertvsnorms2.jpg

We all don't agree on the statement that it just makes the bolt bigger yet, but I hope to give enough information to change that.
With the correct education most of us will come to an understanding.

Now on to the root causes.
#1 is the block and they did redesign it in 00. They also used a slightly different alloy blend. Well that has been what I have been told.

The 93 to 99 block have been known to leak coolant though the casting. Wait I have seen more leak oil than coolant. :o

This is a cross section :o
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/Blockcutaway.jpg

And another :o
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/Blocksection.jpg

One of the block I have in my garage had a leak after 3k from New. I repaired the by welding it, but I learned a lot about the root problem. It appeared that when the block was poured the aluminum splashed up the side. Then as the casting filled the part that splashed had started to cooled. The splashed part did not melt back into the casting. This block had a very small pin hole leak, but as I heated it a line formed. this line actually then grew into two parts with a grey substances in between. This was little waxy and it in part of the off gassing.

I have some pictures after it was fixed. :mellow:

If the treads come out like this I would say the a TimeSert will last.
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/threadsonmainbolt.jpg

http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/threadsoffbolt.jpg

The fact is that is a Main bolt and has NO thread locker on them

This is a head bolt hole and looks pretty good I can see the it is shiny and has no pits or erosion.

http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/shineythreads.jpg

This is a head bolt hole that has pitting and erosion. IT WOULD NOT BE ACCEPTIBLE TO TIMESERT!

http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/hole2threadsnogood.jpg

http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/hole2pits-dark.jpg

This bolt hole we will use for an example.

You can see some deep pits
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/hole1pitting.jpg

http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/hole1pits.jpg

http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/2.jpg

Now I use the TimeSert drill and remove some material. OH no it is not shiny
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/darkdrillfillings.jpg

The pits are still in the block.
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/hole1piits2.jpg

http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/5.jpg

http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/4.jpg

http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/3.jpg

This is a my 99 block that leaked. The casting looks good in the water jackets, but it still leaked.
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/444.jpg


http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/block.jpg

This is the block that I showed drilling out above. I installed a TimeSert in that hole and it pulled out. This is the block after I installed Norm's inserts.
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/afternorms.jpg

This is a lip on the top of the deck that must not be removed.
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/dam.jpg

This is an area that is still bad. It is not in the bolt hole, but coolant leaked into the bolt hole from this area. I pressurize the hole and could see the air coming through the casting
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/afternorms2.jpg

What is it that the TimeSert is going to grip to?
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Some time in the 2003 production run GM switch from 11mm X 1.50mm bolts to 11 X 2.0 bolts. This is a much courser bolts and can grip better. I have not seen 1 failure yet.
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I will start in on the head gasket design flaws now.
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The block and head expand and contract in the heat cycles.
This leads to the head gasket bunching up in this area.
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/432.jpg

Because of this open area the head gasket will look like this.
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/222.jpg

http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/111.jpg



This is an old picture of some of my Good parts. The collection has grown

This is the Deck of a 3.6L VVT engine from a CTS.
The deck is flat and the head gasket is a Multi Layer Metal gasket. I have no picture, but I will get them on Monday. Guess what. I have never seen a failure of a head gasket yet.
http://i224.photobucket.com/albums/dd25/AJxtcman/VVT%20Engine/Picture002.jpg

What is it that the TimeSert is going to grip to?
.
.
.

Some time in the 2003 production run GM switch from 11mm X 1.50mm bolts to 11 X 2.0 bolts. This is a much courser bolts and can grip better. I have not seen 1 failure yet.
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I will start in on the head gasket design flaws now.
.
.
.
.
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The block and head expand and contract in the heat cycles.
This leads to the head gasket bunching up in this area.
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/432.jpg

Because of this open area the head gasket will look like this.
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/222.jpg

http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/111.jpg



This is an old picture of some of my Good parts. The collection has grown

After looking at that you can see that the head gasket can shrink. This will cause a failure.

This is a block from a 4.4L S/C RWD Northstar. As you can see the block has a full deck.
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/RWD%20VVT/44Lupperblock.jpg

This is the Multi Layer Metal head gasket that is used on a RWD Northstar
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/RWD%20VVT/44Lheadgasket.jpg
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/RWD%20VVT/HeadGasket44L.jpg

I have not installed timeserts in several block. I bet that I have rejected more 99 and prior than I have actually install TimeSerts in.

I installed TimeSerts in several 99 and prior blocks and had the inserts pull while torquing them (never left = never came back). I have had several come in that have been done by other tech's at the dealer. This is how I learned what will hold and what will not.

We have a 00 in currently (2/5/2008) with Head gaskets out. Long story, but I will post pictures

Some history
03/12/2003 @ 46998 miles: COVER AND/OR GASKETS, COOLANT PUMP - REPLACE
03/26/2004 @ 58428 miles: COVER AND/OR GASKETS, COOLANT PUMP - REPLACE Not at are Dealer
01/30/2006 @ 74820 miles: J1190 - LOWER CRANKCASE SEAL/SEALANT REPLACEMENT

After the last repair listed. The customer went to another dealer and had the Coolant Cross-over resealed and had been over heated
The customer again stated having over heating issues last summer. He continued to drive it until now.

The front bank head bolts did not crack loose. I have not looked at the head bolts yet and inspected for any signs of aluminum. I will today. The Tech doing the job installs all 20 inserts when he has a failure.

As you can see the material is shiny.
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/2000filings1.jpg


This is a shot of the chips. They are chips and not powder. They are shiny
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/00shinyfilings.jpg

This is a picture of the TimeSert alignment fixture. It has collected minor amount of smaller chip/powder this is not shiny, but it is not like some blocks. On the really bad blocks the drill goes in easy and when you pull the bit out the material you removed is all powdery. Like dust.
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/00filings1.jpg


So this 2000 block will hold the TimeSerts

I JUMPPED SOME POST HERE
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I strongly endorse Norm's inserts. I feel that they are the best thing in most cases for a 99 and prior block. I know of a couple of issues with Norm's kit. It is not that big of a deal. It is not the product, but it does not use a stop collar. This means that the insert may not be set in the same location. If you take your time you can make sure that they all stop in the same location. I am used to the TimeSert kit, so I had two that did not stop at the proper distance. I just let the loctite set and I was good.

This is two of the head bolts. As you can see they have NO aluminum on them. I did not see any of them with aluminum on them.

http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/HeadBolts.jpg

This is one of head gaskets. It really fell apart. This had a lot of stop leak in it
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/00headgasket1cyl.jpg

This is some of that bunching I talk about
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/bunching5.jpg

This part did not look that bad, but It has a lot of stop leak.
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/Headgasket2.jpg

This is some rust on the head gasket
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/HeadGasket3.jpg

This stop leak really attacked the gasket
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/Bunchingupandstopleak.jpg

More of that stop leak build up.
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/Stopleak44.jpg

http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/Stopleak.jpg

http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/Stopleak-1.jpg

http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/Stopleakbuildup.jpg

The stop leak was so thick it plug the holes in the head gaskets and in the heads. Stu (the tech) had to use a drill to clean out the steam holes.

GM will not warranty the Big Timesert or Norm's. GM states that if the bolt hole has erosion you can not TimeSert it and you must Replace the short block.
From my understanding all 1998 cars are now out of Warranty. With in a year all 1999 will be out they will not have any more 1999 and older Certified cars left under warranty.
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JUMPPED POST AGAIN
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I would never purchase a 96 to 99 Cadillac unless it was a 98 or 99 Seville and that maybe limited to a STS.
You can buy a 2002 or 2003 Seville for $6500 with 100K+ miles. A 99 Deville maybe worth $3k to $6K. Subtract the $3000 to $6000 for head gaskets and you have JUNK.
A 99 STS with 100K will go for $9000 now you can fix the car.

The reason I say up to $6000 in head gasket repairs is because of the cam shaft failure in the 93 to 99 models.
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Northstarlifter11.jpg
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Northstarlifer41.jpg
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Northstarlifter21.jpg

the pictures are 4 years old. We had a higher level of zinc then.

http://www.cometic.com/images/Home_1x2.gif (http://www.cometic.com/gaskethome.aspx)

http://www.cometic.com/images/domesticauto.gif


Make: GM
Engine: Cadillac V8 4.6L
Description: Northstar 4.6L 32V Left Side
Bore: 3.700"
Material: MLS / C.O.T. - .065"
StockCode: C5716-065
Pkg Qty: 1
Price: $118.09
http://www.cometic.com/generateImage.aspx?g=/domesticauto/9-C5717.gif

Make: GM
Engine: Cadillac V8 4.6L
Description: Northstar 4.6L 32V Right Side
Bore: 3.700"
Material: MLS / C.O.T. - .065"
StockCode: C5717-065
Pkg Qty: 1
Price: $118.09
http://www.cometic.com/generateImage.aspx?g=/domesticauto/9-C5716.gif

http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/mls.jpg

:thumbsup:

I had forgot about this company until I got a phone call last night.

AJ, are these aftermarket gaskets?

Very interesting writeup AJ, well done. My 98 SLS blew the gasket, but for a different reason than the one that you showed. The metal on my block was great, no pits or corrosion, hell the threads didn't even pull out, what killed mine were two gashes in the surface of the head, near the water jacket. I assume that they were a factory flaw from the factory, but I never did find the reason. In your estimation, since the block was in good shape, no powdered shavings, or pits, what are the chances of my 98 blowing a head gasket again?

AJ, are these aftermarket gaskets?
YES
They maybe the OE supplier of that type of gasket for some engines. I am not sure about that, but some is making then for GM.


Very interesting writeup AJ, well done. My 98 SLS blew the gasket, but for a different reason than the one that you showed. The metal on my block was great, no pits or corrosion, hell the threads didn't even pull out, what killed mine were two gashes in the surface of the head, near the water jacket. I assume that they were a factory flaw from the factory, but I never did find the reason. In your estimation, since the block was in good shape, no powdered shavings, or pits, what are the chances of my 98 blowing a head gasket again?

No pitting, No powder, No TimeSerts then the block should hold up just fine

AJ, It's too bad that CF doesn't pay an hourly rate. Thanks for the extensive homework. The complete set should be a Northstar or Tech sticky.

Thanks for the info, I will watch more carefully when I do another one. Maybe I'm lucky so far!

I did realize there was a difference on some holes when I drilled them but didn't record or check them as well as you have.

My bad holes were very obviously different from my good holes. The good ones snapped really hard when they broke loose and the holes and bolts were dry. The bad ones were wet with coolant (I think). They was a slimy - and silvery coating - it was almost like anti-seize compound on the bolt threads. I think only one of them was completely stripped, but I drilled and inserted them all. I don't recall seeing any powdery aluminum - maybe I missed it.

I have given this a lot of thought, and I think (just a theory - just an opinion) the head gaskets let go first, allowed coolant & exhaust gases into the bolt holes and that degraded and corroded the aluminum to the point where the bolts let go, and the exhaust then entered the cooling system in a big way.

YES




No pitting, No powder, No TimeSerts then the block should hold up just fine

I used the Timeserts on mine, they seemed to lock in nicely and I haven't seen a problem yet after 10,000 miles.

I used the Timeserts on mine, they seemed to lock in nicely and I haven't seen a problem yet after 10,000 miles.

I have TimeSerted many thing over the years. On a Northstar Block the Drill/Ream is centered with a jig and then the drill goes down into the bore about 3" before it drills out the threads. This would mean that it is pretty well centered! Yeah right. The block was square at one time also. :eek: Do you understand that? :stirpot: OK the block goes through heat cycles and the bolt holes become slightly curved. :thumbsup: When the drill gets to the bottom it drills ever so slightly off center. Maybe it goes towards the soft stuff. That would a good thing. Just think about this you have a drill in a 1" collar square to the deck and then it goes into a bore another 3". That means that it is held centered and square by a 4" tube. So why is it that I see so many off center? They hold up, but I just saying. So if one of the 20 hole is not perfect then the block is junk after the TimeSerts have been installed and they fail. If you just fix the bad ones and 75K later a different one fails you can fix the ones needed.

excellent write up this is a very good read if you are a northstar owner.

So AJ, you say that:

If you just fix the bad ones and 75K later a different one fails you can fix the ones needed.

I think you are saying that if you insert all 20 holes at the same time with the initial failure, some of them can be expected to fail again in the future, right?

I think you could be right about that... if the head gasket initial leakage ultimately causes corrosion of the threaded hole in the block, then that same corrosion will take place when the replacement gasket starts to leak after 75K miles or whatever the mileage is. The only thing is, I think the Norm's inserts (I know you are a fan) will hold up longer, since they engage a longer area and they have a coarser/deeper thread. Also, how many cars are worth replacing or even repairing the engine in by the time the second HG has let go?

But if you do all 20 and it lasts longer than 75K miles, then it was better than just doing one. I mean, how many people have had the timeserts fail under normal useage over the years?

So AJ, you say that:

If you just fix the bad ones and 75K later a different one fails you can fix the ones needed.

I think you are saying that if you insert all 20 holes at the same time with the initial failure, some of them can be expected to fail again in the future, right?

I think you could be right about that... if the head gasket initial leakage ultimately causes corrosion of the threaded hole in the block, then that same corrosion will take place when the replacement gasket starts to leak after 75K miles or whatever the mileage is. The only thing is, I think the Norm's inserts (I know you are a fan) will hold up longer, since they engage a longer area and they have a coarser/deeper thread. Also, how many cars are worth replacing or even repairing the engine in by the time the second HG has let go?

Correct on the expected failure and GM changed to a courser bolt in mid 2003
But if you do all 20 and it lasts longer than 75K miles, then it was better than just doing one. I mean, how many people have had the timeserts fail under normal useage over the years?

We see them all the time. If the block has been TimeSerted and a head gasket fails most tech walk away from that engine. Remember the TimeSerts come out with the bolts about 75% + of the time.

Interesting, having not seen a N* apart (only became an owner 2 mos ago) I did not realize GM designed it with an open deck. I've never been a fan of open deck motors, because typically gasket sealing is an issue (especially at *ahem* elevated power levels) along with core shift and distortion of the cylinders, N* block casting issues aside. GM seemed to learn the lesson, since according to your pics the newer RWD N* were redesigned with a closed deck, and they did the same with the LSx series V8s when they were released in '97.

We see them all the time. If the block has been TimeSerted and a head gasket fails most tech walk away from that engine. Remember the TimeSerts come out with the bolts about 75% + of the time.

Right, but how many miles did it go before they went again? I know that there are several members here that did the timeserts and haven't had a problem with it so far.

How common is head gasket failure on the 2000 N*? I'm currently at 115,000 miles. Is it just a matter of time before my gasket blows? Are there any warning signs / symptoms to watch or listen for, something that will warn me that the gasket is about to go?

How common is head gasket failure on the 2000 N*? I'm currently at 115,000 miles. Is it just a matter of time before my gasket blows? Are there any warning signs / symptoms to watch or listen for, something that will warn me that the gasket is about to go?

If you start smelling coolant but not noticing any leaks then it is getting close. Or if you start losing coolant and it isn't leaking then it is probably burning off in the cylinder. Or in alot of cases if your thermometer on the dash isn't right at 12 o clock that can be another indicator.

My question to Aj is what can we do so it doesn't happen again or is it just something that will keep happening ?
If I use those metal gaskets and my holes are all good it wouldn't bunch up at all would it ? And is it fair to say that the poor castings are what may have caused the bolts to pull out of the block ?

AJ question if you have a chance, since my block was timeserted already and i have to pull the front head due to that foreign object jamming open one of my intake valves which may have gotten slapped by the piston, what are the chances I'm going to strip out those inserts? What's the clearance between the piston and the intake valves or is it a straight up interference engine?

Thanks...

If you start smelling coolant but not noticing any leaks then it is getting close. Or if you start losing coolant and it isn't leaking then it is probably burning off in the cylinder. Or in alot of cases if your thermometer on the dash isn't right at 12 o clock that can be another indicator.

Keep in mind that the above test is not fool proof. 2000-2003 Northstars have a known and common problem with the gaskets on the water pump cover (TSB too). When they leak here, they leak really slowly and drip directly onto the hot tranny where it evaporates and smells. Smells exactly like a failed head gasket...

Long story short, the new cover is <$50 and the upgraded gasket is about $7.00... If you smell coolant don't panic there are lots of other things that are significantly more likely.

excellant writeup. thekey to the kix is the courser threads. woth the fine thread timeserts, there is less material between each thread so it can pull easier. give me a big honking cousre head bolt any day!!

AJ question if you have a chance, since my block was timeserted already and i have to pull the front head due to that foreign object jamming open one of my intake valves which may have gotten slapped by the piston, what are the chances I'm going to strip out those inserts? What's the clearance between the piston and the intake valves or is it a straight up interference engine?

Thanks...

I missed this.
I did a similar job last summer. The valve face and seats were beat up. That was it. You will find out if the TimeSerts stay in place, pull out:suspense:, unscrew, or the worst partially unscrew:eek:

New pictures
This is Highline Cady's 2003 DHS

This is the head gaskets. It looks pretty good.
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/Berts/HPIM0097.jpg

http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/Berts/HPIM0106.jpg

http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/Berts/HPIM0101.jpg

http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/Berts/HPIM0096.jpg

http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/Berts/HPIM0103.jpg

These picture shows some signs of bunching up.
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/Berts/HPIM0099.jpg

http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/Berts/HPIM0102.jpg

http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/Berts/HPIM0100.jpg

http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/Berts/HPIM0104.jpg

http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/Berts/HPIM0105.jpg

This is the head bolt conversion

Stock up to 2004
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/Berts/HPIM0107.jpg

As you can see they came out clean, but all the threads were pitted.
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/Berts/HPIM0108.jpg

2004 bolts
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/Berts/HPIM0109.jpg

Comparision of the pre 2004 and the 2004 and up.
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/Berts/HPIM0110.jpg
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/Berts/HPIM0111.jpg
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/Berts/HPIM0112.jpg
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/Berts/HPIM0113.jpg

Yeah do they ever feel nice going into the new GM TimeSerts. A++++

Nice pics AJ - your photography is improving ;-)

interestin story..very technical but extremely upsettin...basically what im sayin is like i always say....cadillac engineers should b taken to da shed!! seems they know the problems but peddle the machine anyway, kinda like throwin ......against the wall and see how much sticks...knowin a few will cum back under wanrranty, hopin most wont...all vehicles have inherent probs. but this is a very good reason gm is losing mkt share...huge huge prices low low quality...seems u all seem to say they is prob with the block before it even in a manufacture state! i know in my biz if i treated my clients like this they would horsewhip me...and if i knew of problems in production and design but provided them with the product anyway knowin it was gonna stand a very very big chance of failure..well, then i deserve to b horsewhipped AND put out of biz...hate to tell u guys but u dudes r pushin me back to audi and mercedes yeah they got thier problems but aint NOTHING like the stuff i read here...

Nice pics AJ - your photography is improving ;-)

I think I said this before. Some of the pictures were old. My screen on my camera broke about 6 months ago:crybaby:.

I have a new HP Mz67 and I like it!:thumbsup:

interestin story..very technical but extremely upsettin...basically what im sayin is like i always say....cadillac engineers should b taken to da shed!! seems they know the problems but peddle the machine anyway, kinda like throwin ......against the wall and see how much sticks...knowin a few will cum back under wanrranty, hopin most wont...all vehicles have inherent probs. but this is a very good reason gm is losing mkt share...huge huge prices low low quality...seems u all seem to say they is prob with the block before it even in a manufacture state! i know in my biz if i treated my clients like this they would horsewhip me...and if i knew of problems in production and design but provided them with the product anyway knowin it was gonna stand a very very big chance of failure..well, then i deserve to b horsewhipped AND put out of biz...hate to tell u guys but u dudes r pushin me back to audi and mercedes yeah they got thier problems but aint NOTHING like the stuff i read here...


I have a FIX.
MLS head gaskets and Norm's inserts or Timesert Big inserts ( I have not used )

Has anyone had a HG fail after inserting and replacement. I don't mean have the inserts failed... I know they sometimes fail in the '96-99 blocks with powdery aluminum. I am asking if the factory (or Fel-Pro like I used) head gaskets fail, like after say 25-50K miles. I think they might, since I am pretty convinced that the gasket fails and that causes the threads to be contaminated and fail, but I was wondering if anyone has had that happen after repairs?

This is a little information on coolant. I am still testing the coolant when I service it, but I have not found any that has been acidic.

TSB #00-06-02-006D: Engine Coolant Recycling and Warranty Information
Portion of the bulletin that talks about Sealing Tabs and Dex-Cool

Sealing Tablets
Cooling System Sealing Tablets (Seal Tabs) should not be used as a regular maintenance item after servicing an engine cooling system. Discoloration of coolant can occur if too many seal tabs have been inserted into the cooling system. This can occur if seal tabs are repeatedly used over the service life of a vehicle. Where appropriate, seal tabs may be used if diagnostics fail to repair a small leak in the cooling system. When a condition appears in which seal tabs may be recommended, a specific bulletin will be released describing their proper usage.

Water Quality
The integrity of the coolant is dependent upon the quality of DEX-COOL® and water. DEX-COOL® is a product that has enhanced protection capability as well as an extended service interval. These enhanced properties may be jeopardized by combining DEX-COOL® with poor quality water. If you suspect the water in your area of being poor quality, it is recommended you use distilled or de-ionized water with DEX-COOL®.

"Pink" DEX-COOL®
DEX-COOL® is orange in color to distinguish it from other coolants. Due to inconsistencies in the mixing of the dyes used with DEX-COOL®, some batches may appear pink after time. The color shift from orange to pink does not affect the integrity of the coolant, and still maintains the 5 yr/150,000 mile (240,000 km) service interval.

Back Service
Only use DEX-COOL® if the vehicle was originally equipped with DEX-COOL®.

Contamination
Mixing conventional green coolant with DEX-COOL® will degrade the service interval from 5 yrs./150,000 miles (240,000 km) to 2 yrs./30,000 miles (50,000 km) if left in the contaminated condition. If contamination occurs, the cooling system must be flushed twice immediately and re-filled with a 50/50 mixture of DEX-COOL® and clean water in order to preserve the enhanced properties and extended service interval of DEX-COOL®.

After 5 years/150,000 miles (240,000 km)
After 5 yrs/150,000 miles (240,000 km), the coolant should be changed, preferably using a coolant exchanger. If the vehicle was originally equipped with DEX-COOL® and has not had problems with contamination from non-DEX-COOL® coolants, then the service interval remains the same, and the coolant does not need to be changed for another 5 yrs/150,000 miles (240,000 km).


Think about the head gaskets
TSB #05-06-02-001: Information on Aluminum Heater Core and/or Radiator Replacement

The following information should be utilized when servicing aluminum heater core and/or radiators on repeat visits. A replacement may be necessary because erosion, corrosion, or insufficient inhibitor levels may cause damage to the heater core, radiator or water pump. A coolant check should be preformed whenever a heater core, radiator, or water pump is replaced. The following procedures/ inspections should be done to verify proper coolant effectiveness.

Technician Diagnosis

Verify coolant concentration. A 50% coolant/water solution ensures proper freeze and corrosion protection. Inhibitor levels cannot be easily measured in the field, but can be indirectly done by the measurement of coolant concentration. This must be done by using a Refractometer J 23688 (Fahrenheit scale) or J 26568 (centigrade scale), or equivalent, coolant tester. The Refractometer uses a minimal amount of coolant that can be taken from the coolant recovery reservoir, radiator or the engine block. Inexpensive gravity float testers (floating balls) will not completely analyze the coolant concentration fully and should not be used. The concentration levels should be between 50% and 65% coolant concentrate. This mixture will have a freeze point protection of -34 degrees Fahrenheit (-37 degrees Celsius). If the concentration is below 50%, the cooling system must be flushed.

Inspect the coolant flow restrictor if the vehicle is equipped with one. Refer to Service Information (SI) and/or the appropriate Service Manual for component location and condition for operation.

Verify that no electrolysis is present in the cooling system. This electrolysis test can be performed before or after the system has been repaired. Use a digital voltmeter set to 12 volts. Attach one test lead to the negative battery post and insert the other test lead into the radiator coolant, making sure the lead does not touch the filler neck or core. Any voltage reading over 0.3 volts indicates that stray current is finding its way into the coolant. Electrolysis is often an intermittent condition that occurs when a device or accessory that is mounted to the radiator is energized. This type of current could be caused from a poorly grounded cooling fan or some other accessory and can be verified by watching the volt meter and turning on and off various accessories or engage the starter motor. Before using one of the following flush procedures, the coolant recovery reservoir must be removed, drained, cleaned and reinstalled before refilling the system.


Flushing Procedures using DEX-COOL®

Important: The following procedure recommends refilling the system with DEX-COOL®, P/N 12346290 (in Canada, use P/N 10953464), GM specification 6277M. This coolant is orange in color and has a service interval of 5 years or 240,000 km (150,000 mi). However, when used on vehicles built prior to the introduction of DEX-COOL®, maintenance intervals will remain the same as specified in the Owner's Manual.


If available, use the approved cooling system flush and fill machine (available through the GM Dealer Equipment Program) following the manufacturer's operating instructions.

If approved cooling system flush and fill machine is not available, drain the coolant and dispose of properly following the draining procedures in the appropriate Service Manual. Refill the system using clear, drinkable water and run the vehicle until the thermostat opens. Repeat and run the vehicle three (3) times to totally remove the old coolant or until the drained coolant is almost clear. Once the system is completely flushed, refill the cooling system to a 50%-60% concentration with DEX-COOL®, P/N 12346290 (in Canada, use P/N 10953464), GM specification 6277M, following the refill procedures in the appropriate Service Manual.

If a Service Manual is not available, fill half the capacity of the system with 100% DEX-COOL®, P/N 12346290 (in Canada, use P/N 10953464), GM specification 6277M. Then slowly add clear, drinkable water (preferably distilled) to the system until the level of the coolant mixture has reached the base of the radiator neck. Wait two (2) minutes and reverify the coolant level. If necessary, add clean water to restore the coolant to the appropriate level.


Once the system is refilled, reverify the coolant concentration using a Refractometer J 23688 (Fahrenheit scale) or J 26568 (centigrade scale) coolant tester, or equivalent. The concentration levels should be between 50% and 65%.

This is the head bolt conversion

2004 bolts
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/Berts/HPIM0109.jpg

Comparision of the pre 2004 and the 2004 and up.
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/Berts/HPIM0110.jpg

Yeah do they ever feel nice going into the new GM TimeSerts. A++++

For all you Northstar haters. The 2004 head bolt TimeSert are the same as the LSx engines use!:thumbsup:

So I converted a 2003 Northstar the LSx head bolt threads!!!

Ok, my son has a 99 STS and the head gaskets went. On the rear head all head bolts snapped loose upon removal. (Front not yet pulled, figured rear would be the worse due to heat. Gasket bunching evident.) So far looks like no coolant made it to the head bolt threads so I suspect we may not have the “gray dust of death” when we drill and tap for inserts. None were mushy. We have, the following kits M11-1.5 time-sert, M11-1.5Big-sert and M11-2.0 time-sert.
So the coarse thread gets a better bite into the aluminum and GM does not warranty the Big-serts. So I am leaning toward the M11-2.0 inserts. The engine came out the top due to lack of facilities, so we want to do this once and do not want to go back. The gasket kit that will be used is Felpro.

To be able to utilize the M11-2.0 inserts, what bolts do I purchase? I believe the later engines used two different lengths of head bolts. Are the LSx bolts the same length as the ’97-’99 Northstar? If so I would just purchase 3 sets of LSx bolts and be set.
Thanks
STS Tom


:confused::

1994 to 1999 Head bolt Part number ------- 1647217
Thread size ------------------------------- M11 x 1.5 x 30mm
Bolt Length (under washer) --------------- 139.9 mm
Bolt Thread length ------------------------ 44.5 mm
Hole depth ------------------------------- 75 mm
Cylinder head boss height ----------------- 76.0 mm
Counter bore depth ----------------------- 35 mm

2000 to 2003 Head Bolt Part Number ------ 12557775
Thread size ------------------------------ M11 x 1.5 x 30 mm
Bolt Length (under washer) -------------- 157.2 mm
Bolt Thread length ----------------------- 45.3 mm
Outboard hole depth --------------------- 96.5 mm
Counter bore depth ---------------------- 51.5 mm
Inboard hole depth ---------------------- 80 mm
Counter bore depth ---------------------- 35 mm
Cylinder head boss height - outboard ----- 76.0 mm
Cylinder head boss height - inboard ------- 92.5 mm

2004 to 2008 Head bolt Part Number -----11589058
Thread size ---------------------------- M11 x 2.0 x 30 mm
Bolt Length (under washer) ------------- 157.2 mm
Bolt Thread length ---------------------- 64.8 mm
Outboard hole depth -------------------- 89.5 mm
Counter bore depth --------------------- 45.5 mm
Inboard hole depth ---------------------- 73 mm
Counter bore depth --------------------- 29 mm
Cylinder head boss height - outboard ---- 76.0 mm
Cylinder head boss height - inboard ------ 92.5 mm

If you but a set of 2004+ bolts and cut 17.3 mm off the bottom you will have 47.5 mm of threads left on the bolt. The 94 to 99 have only 44.5 mm on them. So the 2004 bolts will have 3 mm more.

1994 to 1999 Head bolt Part number ------- 1647217
Thread size ------------------------------- M11 x 1.5 x 30mm
Bolt Length (under washer) --------------- 139.9 mm
Bolt Thread length ------------------------ 44.5 mm
Hole depth ------------------------------- 75 mm
Cylinder head boss height ----------------- 76.0 mm
Counter bore depth ----------------------- 35 mm

2000 to 2003 Head Bolt Part Number ------ 12557775
Thread size ------------------------------ M11 x 1.5 x 30 mm
Bolt Length (under washer) -------------- 157.2 mm
Bolt Thread length ----------------------- 45.3 mm
Outboard hole depth --------------------- 96.5 mm
Counter bore depth ---------------------- 51.5 mm
Inboard hole depth ---------------------- 80 mm
Counter bore depth ---------------------- 35 mm
Cylinder head boss height - outboard ----- 76.0 mm
Cylinder head boss height - inboard ------- 92.5 mm

2004 to 2008 Head bolt Part Number -----11589058
Thread size ---------------------------- M11 x 2.0 x 30 mm
Bolt Length (under washer) ------------- 157.2 mm
Bolt Thread length ---------------------- 64.8 mm
Outboard hole depth -------------------- 89.5 mm
Counter bore depth --------------------- 45.5 mm
Inboard hole depth ---------------------- 73 mm
Counter bore depth --------------------- 29 mm
Cylinder head boss height - outboard ---- 76.0 mm
Cylinder head boss height - inboard ------ 92.5 mm

If you buy a set of 2004+ bolts and cut 17.3 mm off the bottom you will have 47.5 mm of threads left on the bolt. The 94 to 99 have only 44.5 mm on them. So the 2004 bolts will have 3 mm more.

Will someone check my math on this please. Thank A.J.

A.J. Math looks good. I'll check later with pencil and paper.. So what do I do for lube/sealant after I cut the precoated portion of the bolt off ?
On VW water boxers head nuts, I have used a pipe joint compound with Teflon. On the VW the coolant comes up the stud and rusts the cap nut to the stud. Years later attempted removal, breaks the stud.
Is there any equivalent coating for the original coating on the head bolts ?
On the used bolts it looks like installing them smears the coating up the bolt.
From what I understand the coating has micro spheres of thread lock and must be torqued within something like 30 minutes after being run into a hole.
Also does GM use coatings on the head bolts that go into iron blocks ? The cut-down bolts will be going into a steel threaded hole with the inserts. I wonder if the coating is there originally to prevent galvanic corrosion between the steel bolt and aluminum block.
Regards
STS Tom Sr.

A.J. Math looks good. I'll check later with pencil and paper.. So what do I do for lube/sealant after I cut the precoated portion of the bolt off ?
On VW water boxers head nuts, I have used a pipe joint compound with Teflon. On the VW the coolant comes up the stud and rusts the cap nut to the stud. Years later attempted removal, breaks the stud.
Is there any equivalent coating for the original coating on the head bolts ?
On the used bolts it looks like installing them smears the coating up the bolt.
From what I understand the coating has micro spheres of thread lock and must be torqued within something like 30 minutes after being run into a hole.
Also does GM use coatings on the head bolts that go into iron blocks ? The cut-down bolts will be going into a steel threaded hole with the inserts. I wonder if the coating is there originally to prevent galvanic corrosion between the steel bolt and aluminum block.
Regards
STS Tom Sr.

http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/Berts/HPIM0109.jpg
The thread pitch is 2.0
So I counted the thread and you will sill have some of the blue stuff. T would think putting blue loctite on the bolt would work. Not really sure I have never done this. THESE BOLTS ARE VERY STRECHY! When torquing you turn them 60° and the turn back about 5°:mad: It was a little tricky

Torque Specifications:

1993-1999 Head Bolt Torque

First Pass ----- 30 lb ft
Second Pass -- +70°
Third Pass ---- +60°
Fourth Pass -- +60° (190 Degrees total)




2000-2003 Head Bolt Torque:

First Pass ------ 30 lb ft
Second Pass -- +70°
Third Pass ---- +60°
Fourth Pass -- +45° (175 Degrees total)




2004-2008 Head Bolt Torque:

First Pass ------ 22 lb ft
Second Pass -- +60°
Third Pass ---- +60°
Final Pass ---- +60° (180 degrees Total)

http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/Berts/HPIM0109.jpg
The thread pitch is 2.0
So I counted the thread and you will sill have some of the blue stuff. T would think putting blue loctite on the bolt would work. Not really sure I have never done this. THESE BOLTS ARE VERY STRECHY! When torquing you turn them 60° and the turn back about 5°:mad: It was a little tricky

So when the headgaskets are done on pre 2004 are they retapped for these bolts ? If not could that be done ?

So when the headgaskets are done on pre 2004 are they retapped for these bolts ? If not could that be done ?

The 2000 to 2003 can be upgraded.

The 2000 to 2003 can be upgraded.

when you do them do you upgrade them ?

when you do them do you upgrade them ?

Highline Cady's was the first one. we can't get any of the newer TimeSerts. We just don't have a sorce. We don't buy them from GM. We buy them from the worlds largest distributor of TimeSert inserts. They don't have a listing. :banghead:
I need 20 more Now:bomb:

Well if mine ever go I at least I know what to ask for and what should be used. And it's all thanks to you AJ. :)

Aj, have you used the cometic gaskets before? I have heard of sealing problems and the need for cooper spray. I just ordered norms and agree MLS looks like the way to go. Just looking for some good advice before spending the money.

Not yet. I have been too busy to add to your thread. I did read it. I am hoping to get caught up in my reading this weekend

I had my heads pressure checked, didn't find any issues with them. In my case, it looked like my gasket blew between 2 cylinders. I remember while taking off the head bolts that the bolts by the cylinder that had the most coolant/water mixture was rather loose and not difficult at all to get off. All other head bolts were pretty difficult to remove. I believe in my case, the head bolt started receiving coolant, (possibly through the short block like you state in this thread), head bolt gets loose, pressure removes part of the gasket and walaa... in comes the water to my cylinder.

I appreciate greatly all the technical advice and the documentation of this thread. I do have some questions though.

I have a 99 deVille Concours in premium condition with 133K miles that I believe the head gaskets just failed. Sudden coolant usage and smell; large bubbles in the coolant resevoir observed (with cap off) that when 'pop' steam or exhaust is released. After it sat a week without being used, this weekend I started it up and now has large amounts of white 'smoke' coming from both exhaust pipes. This car has NEVER overheated, even to date. Car was well maintained. The car is still in extremely excellent shape, no scratches, dings, etc. So, this isn't a 'throw away' even though according to some of the blogs and threads I have been reading that the northstar engine may be a 'throw away'. Unbelievable that the engine that essentially 'brought back Cadillac' has such a failure record.

While I have read many of the posts, I need to simplify exactly what I should do; what is the wisest choice. I plan on removing the engine and cracking it open to determine the head bolt to block situation to determine if my engine is salvagable. No water in the oiling system so that is a good thing but what I am reading about the timeserts and powdery block alloy is disconcerting.

I see by the threads that the '99 is one of the 'bad' engines as far as timeserting...I also read that the mid 2003 the factory head bolt upgrade to LSx style bolts has a better record. So that leads me to think that the 2004 and above FWD northstars are the way to go whether used engine or a remanufactured engine knowing there were some changes with coils, etc. I saw in the above post that the post '99s are not a simple 'bolt in' replacement for a '99 and prior but I must ask what other changes would there be?

It is also my understanding that the closed deck design of the RWD northstar WILL NOT be usable in my FWD; is this correct?

So, essentially, it is my understanding that the 2004 will bolt in (with modifications) but with the LSx head bolt design this is the better choice?

It is also my understanding that the '99 northstar doesn't accept timeserts (or Norm's) very well but the 2000 thru 2003 will?

One other question: I saw something in one of the posts about someone not wanting to own a deVille up to 99 but a '98 and '99 STS is better? Was there a difference in the engine for the STS (300hp) over that of the Concours (300hp as opposed to the 275hp of the regular deVille)? Maybe it was just that, the engine horsepower. I thought the STS and the Concours had the exact same engine.

Sorry for the length of the post but there is so much information out there that I want to ensure that I am in full understanding. I might be crazy about wanting to keep my car (I actually was going to keep it indefinitely once I took it out of everyday service) but I really love the car. 300HP, and at 26mpg at 80mph is hard to beat! Add to that the quiet ride and the size of the car and its safety features (over a tin can at 33mpg) I can't find anything acceptable to replace it.

AJ so when doing time serts on a 2003 if one wanted to upgrade would they get the 2004 timesert kit?????

AJ so when doing time serts on a 2003 if one wanted to upgrade would they get the 2004 timesert kit?????

Correct

would it be worth it to do the upgrade b/c the new bolts would just be going into the time-sert? Or is the time sert insert itself have courser threads also???

would it be worth it to do the upgrade b/c the new bolts would just be going into the time-sert? Or is the time sert insert itself have courser threads also???

Oh yeah the 04 TimeSerts have the courser threads on the outside

cool good info thanks

would it be safe to say, that for preventitive maintenance it would be a good idea to put a lower temp thermostat in the car? It seems that would greatly help this car, to never get that hot. is it coincidence that northstar run hotter then most all other cars, and they have the most head gasket failure's due to heat and the expanding / contracting of metals also due to heat.

you might loose a mpg if you got it to run at 185-190 instead of 210-220, but it seems well worth it.

Iv done a bunch of these the only system that works is Norms,,,ns300L ,,,PLAIN AND SIMPLE!!! OVER!

would it be safe to say, that for preventitive maintenance it would be a good idea to put a lower temp thermostat in the car? It seems that would greatly help this car, to never get that hot. is it coincidence that northstar run hotter then most all other cars, and they have the most head gasket failure's due to heat and the expanding / contracting of metals also due to heat.

you might loose a mpg if you got it to run at 185-190 instead of 210-220, but it seems well worth it.

The northstar LOVES to run cold from what i know.


Either way, i would just like to state that i have been changing coolant every 5-15k miles in my 98 and i have no HG issues.

So after all this, I have a 99 STS, eventually something will happen to the head gaskets.. hopefully at 200k or more :> What is the best thing to do?
Upgrade the block or use norm's? I couldn't quite get what is best to do if you have a 96-99.. Thanks

I sure like all that head gasket talk. My 95 Eldorado beauty recently started overheating (done it twice now) and I hear it's the HG b/c my coolant goes low just after it overheats.
I did find out that I had the wrong cap on the expansion tank and I had air in the system. After the first overheat 2 weeks ago I drained and refilled the coolant. 50/50 Dex/distilled but I didn't burp it much.

Well now it overheated for the 2nd time and so I had the system flushed today at Goodyear. Seems fine for now. They did a pressure test on the cooloing system, passed.
It's not missing, never has; It's never had a problem far as I can tell. I drove around in the heat today, the temp. stayed around 228F. Granted it's 100 degrees F in Tucson AZ.
And my oil looks good.

Is there any other way that exhaust can get into the coolant mix other than thru a breached headgasket? Could it be throttle body seals or pitting or something else??

One more Question; Is 130k a lot of miles for a Northstar compared to other engines? I thought these engines were revolutionary and love the hwy, plus some hard acceleration only makes them better! ?


http://i153.photobucket.com/albums/s222/hotpotatapie/HPNX0742.jpg

Nice looking car. Exhaust can get into the cooling system from other places, but a leaking HG is by far the most common. 100 degrees sounds good - I am in Phoenix - it's always 5-10 degrees hotter here than there

Almost a month ago, dubya opined that there might be a Northstar bandaid applied by running the engine colder.....phooey!!! An internal combustion engine is a heat creator and a heat user: the hotter it runs (within limits) the more efficient it is. Problem is that we need to use low boiling point coolants under pressure to insure that the car and engine accessories don't cook. It makes not one whit, temperature-wise, where the engine runs, as long as the various gasketed parts are held tightly together and expand and contract at pretty much the same rates.

The problem with the Northstar is that 10 head bolts (per head) is damn few for an aluminum engine with high power-per-cubic-inch ratings, especially one that has an inherently weak open deck design. There would be NO head gasket problems if there were a half-dozen more head bolts, or if the deck had been closed and supplied with necessary coolant and steam passages. The block should have been inserted as a part of the original casting process and fitted with studs, not bolts. Less than 1/4" of gasket between cylinder wall and coolant passage, especially in an aluminum engine, is a sure recipe for disaster and if someone wanted to ruin GM, start a class action lawsuit with head gasket failure customers. Ask for a new, redesigned Northstar which would at least operate in the original warranty period. Our problem is that, unlike a sponsored IMSA or NASCAR, we can't afford to rebuild/buy new engines every 1,250 miles.

Tateos, Sounds like you've been through it with the headgasket re-build of a late 90's N*. I take it the inserts are working. Do you think the aluminium from a 95 N* block has a chance at being tough enough for a drill and insert scenario to work? How's Phoenix treating you and your Cadi? My car is running good for now, which is kinda wierd. In any case, let me know if you ever get to Tucson.

Any feedback on the Norms NS300L inserts and the Cometic gaskets?

Mark

I used Norm's - great kit. I used FelPro gaskets - no problem so far

I appreciate greatly all the technical advice and the documentation of this thread. I do have some questions though.

I have a 99 deVille Concours in premium condition with 133K miles that I believe the head gaskets just failed. Sudden coolant usage and smell; large bubbles in the coolant resevoir observed (with cap off) that when 'pop' steam or exhaust is released. After it sat a week without being used, this weekend I started it up and now has large amounts of white 'smoke' coming from both exhaust pipes. This car has NEVER overheated, even to date. Car was well maintained. The car is still in extremely excellent shape, no scratches, dings, etc. So, this isn't a 'throw away' even though according to some of the blogs and threads I have been reading that the northstar engine may be a 'throw away'. Unbelievable that the engine that essentially 'brought back Cadillac' has such a failure record.

While I have read many of the posts, I need to simplify exactly what I should do; what is the wisest choice. I plan on removing the engine and cracking it open to determine the head bolt to block situation to determine if my engine is salvagable. No water in the oiling system so that is a good thing but what I am reading about the timeserts and powdery block alloy is disconcerting.

I see by the threads that the '99 is one of the 'bad' engines as far as timeserting...I also read that the mid 2003 the factory head bolt upgrade to LSx style bolts has a better record. So that leads me to think that the 2004 and above FWD northstars are the way to go whether used engine or a remanufactured engine knowing there were some changes with coils, etc. I saw in the above post that the post '99s are not a simple 'bolt in' replacement for a '99 and prior but I must ask what other changes would there be?

It is also my understanding that the closed deck design of the RWD northstar WILL NOT be usable in my FWD; is this correct?

So, essentially, it is my understanding that the 2004 will bolt in (with modifications) but with the LSx head bolt design this is the better choice?

It is also my understanding that the '99 northstar doesn't accept timeserts (or Norm's) very well but the 2000 thru 2003 will?

One other question: I saw something in one of the posts about someone not wanting to own a deVille up to 99 but a '98 and '99 STS is better? Was there a difference in the engine for the STS (300hp) over that of the Concours (300hp as opposed to the 275hp of the regular deVille)? Maybe it was just that, the engine horsepower. I thought the STS and the Concours had the exact same engine.

Sorry for the length of the post but there is so much information out there that I want to ensure that I am in full understanding. I might be crazy about wanting to keep my car (I actually was going to keep it indefinitely once I took it out of everyday service) but I really love the car. 300HP, and at 26mpg at 80mph is hard to beat! Add to that the quiet ride and the size of the car and its safety features (over a tin can at 33mpg) I can't find anything acceptable to replace it.


Did anyone ever respond to this post? You're describing my car & situation exactly. If I'm going to pull the motor I would love to replace it with a later model that would basically bolt in and is not known for HG failure.

My post is the previous one. What I meant to say is that the condition of my car is identical to the one described, the symptoms are not identical. I am mainly asking if a late model motor will go into a '99 Concours. I really hate to lose the rest of the car if I need HG's and paying the dealer $5,500 to do it makes keeping the car a tough decision if the motor / block is likely to fail again due to the serts. They're quoting 35 hours labor and $1,900 in parts to sert all 20 holes.

The problem with the Northstar is that 10 head bolts (per head) is damn few for an aluminum engine with high power-per-cubic-inch ratings, especially one that has an inherently weak open deck design. There would be NO head gasket problems if there were a half-dozen more head bolts, or if the deck had been closed and supplied with necessary coolant and steam passages. The block should have been inserted as a part of the original casting process and fitted with studs, not bolts.

SubMariner said it best. It appears that Even if you are willing to pull your motor and replace the head gasket, Your head bolts probably won't hold once threaded into the block for the 2nd time. They might hold for a while??

As above, Inserts should have been part of the original casting with studs instead of bolts. Imagine a bullet proof N* for your Cadi :dance:

Did Cadillac get over this Head Gasket problem in the 2000 N* redesign/2nd Generation business???

F*@%$! it, Buy a Reman motor for a late 90's Eldorado or STS and put it in?

I called a car lot about a 98 Eldo touring coupe. The lot owner drives this car home daily. He said after a few miles he discovered it had a blown head gasket and had it fixed with a local engine rebuilder. He said he had the repair bill of $2,500. He said he has put 1,000 miles on the car with no troubles and uses that shop regularly.

I called the shop to see what they do to fix the head gaskets for $2500. They said that they leave the engine in the car, pull the heads off, and re-drill the block to accept larger head bolts. He claims that the shop has done ten Northstars that way and none have returned. I asked him if there would be any difference in labor price if I bought a car needing gaskets and we went with head studs in stead. He said the labor would be the same, but I would need to find out what head studs would fit it. If I go that rout, anyone know what head stud to use? Would converting to studs help solve future head gasket problems by preventing reverse torque on the new inserts or will it hide potential in block stud corrosion problems by allowing seepage in some studs to go undetected in future H/G replacements?

I am new to the Northstar- I do not yet own one, but have always wanted a 95 up touring coupe as a daily driver and autocross racer. I have been told you cannot take the engine out from the top side, but someone said they did that with an STS. Is this shop nuts for doing the head job “in car”? Can I assume they use inserts and are not placing oversized bolts directly into a tapped aluminum hole?

I just now started learning about the cars and the head gasket problems. The shop that does those repairs does not think the Northstar is the right choice for me because I will be driving a 66 mile round trip seven days a week and do not have time to work on cars. They feel the Northstar is unreliable. However, I have seen several for sale with above 240,000 miles that have good running non-smoking engines. Those cars were at the price I could afford, but I don’t want to race a car with a quarter of million miles on it. I’m thinking of buying a nicer car with blown gaskets and using this shop to (or a mechanic friend) to perform this type of repair job if it will work. That will make hot rodding this car affordable (IF this shop can do a REAL fix for $2500, that means my mechanic can do the same thing for much less). I would then have about $3,000 TOTAL in the car total (minus wheels/tires, wing, and other racing goodies).

I don’t want to buy a car, use my entire budget, blow the gaskets and park it. I want to drive care free and blow away a few Mustangs and Trans Ams in autocross races--- NOT a few head gaskets. I want a motor strong enough I can put a mild performance cam in and drive for years.

I have the reliability I need NOW with my unfinished hot rod project: a 3680 lb. 1982 Eldorado with a TBI injected 472. I can overhaul that engine, put on some stiffer torsion bars, monster sway bars, and 17 X 9.5” Vette wheels, for less money than it would take to buy and repair a 95 up Touring coup, but I will get 5 MPGs less and will not look near as good (In my opinion). Should I build that car instead? Or How do I get the Northstar hold up? No one has yet answered the question about a later model engine swap. If I buy a 95 Elo ETC, can I eventually put a 2005 engine in it when the budget allows? It there enough room under the 95 Eldo hood to convert the car back to an old school forward mounted 500 on the side mounted FWD transmission?

Sorry for the long post…

Thanks,
Cody

P.S. I wish gas was still cheap enough I could drive my 1970 Eldorado. It was the coolest car ever built.

SubMariner said it best. It appears that Even if you are willing to pull your motor and replace the head gasket, Your head bolts probably won't hold once threaded into the block for the 2nd time. They might hold for a while??

As above, Inserts should have been part of the original casting with studs instead of bolts. Imagine a bullet proof N* for your Cadi :dance:

Did Cadillac get over this Head Gasket problem in the 2000 N* redesign/2nd Generation business???

F*@%$! it, Buy a Reman motor for a late 90's Eldorado or STS and put it in?


That's what I'm wondering about, can a late model (non HG prone) motor be put in the car without having fabrication / pcm issues?

Is the Eldo or STS less prone to HG issues? I assumed a N* is a N* in the 96-99 model range.

That's what I'm wondering about, can a late model (non HG prone) motor be put in the car without having fabrication / pcm issues?
No
Is the Eldo or STS less prone to HG issues?
No.
I assumed a N* is a N* in the 96-99 model range.
Correct.

No

No.

Correct.

Thanks. That's what I needed to know. Not what I had hoped for though...

How can you tell if your 03DTS has 11x1.5 vs the 11x2 head bolts.

CadVetteStang, Before you get into a vehicle with a FWD Northstar and then try to modify it, I suggest you do some extensive homework in here, up in Seville/Deville, down in the Cadillac Technical forums, and read the Cadillac Technical Archive, up ^^ in the lower left black bar. You may just stick with a RWD warhorse that has catalogs full of aftermarket parts, whereas the FWD Seville/Eldorado/Deville Cadillac has essentially none.

Your question about changing to a performance cam is telling......as the Northstar has 4 chain-driven cams, and there are no aftermarket cams or grinds for street, you're already behind the power curve (Refers to water across the reactor core vs. temperature developed for creating steam.......).

Like SubMariner said, do some research at this site, there is more here than you could poss. absorb. You'd have to quit your job. The Head Gasket talk is endless, it permeates in a lot of different conversations and threads. All things spoken, I will eventually need to find a new motor for Sadie, 1995 Eldorado....I priced rebuilt 2000+ N* at 3,500 + core, from Accurate Engines. Crate delivery.

Since my Cadi is the best ever... I will push the point and extract info from the Cadi Forum to do this!...With some help It can def. be done.
http://i153.photobucket.com/albums/s222/hotpotatapie/HPNX0739.jpg
http://i153.photobucket.com/albums/s222/hotpotatapie/HPNX0742.jpg
http://i153.photobucket.com/albums/s222/hotpotatapie/HPNX0749.jpg

My parents purchased my grandmothers Caddy when she passed away back in 03. It was a 98 Deville with only 37K very pampered miles. The coolant was flushed every 2 years(my uncle knew all about the N* problems) and the vehicle was taken out once a week by that same uncle to "blow it out". Anyway, fast forward to 05 and my parents are driving to Virginia to visit my sister. To make this trip they have to drive on I-64 through the mountains of West Virginia. Guess what happens? Head gaskets blow going uphill. After a lot of grief getting it to Virginia and back home they get it into the Caddy dealer. Exactly as AJ said, they had done quite a few HG's at this point and said that since the car had such low miles and was maintained so well(less than 42K when the failure occured) that the repair had a good chance of working, maybe 50%. Six months later my mom notices a coolant smell and the low coolant message coming on in the dash. Fast forward a couple of years when I move back to my stomping grounds and sure enough the timeserts have failed. The car at this point only has 59K on it, and Mom won't even drive it across town for fear of blowing it up. So, long story short, the timesert "fix" is definately a very expensive($3200 at the Caddy dealer, GM helped out a little bit because of the maintenance records, them being the selling dealer, and low mileage) band aid that can unfortunately peel off at any time. We ended up taking it to a local Ford dealer here that I used to work for that are known crooks and traded it in on a low mileage Mustang.(Mom always wanted one) What is really sad is that as much as I love Caddys I am scared off of the newer ones. I can afford a newer N* Caddy but will not buy one for fear of HG failure. That's why I drive a 91 with a less powerful and refined yet vastly more reliable 4.9. I love the N* when it's running right, not much can beat it for for power and effeciancy. It's too bad that GM won't(and with their current financial situation, can't) stand behind these vehicle and their owners by providing an extended warranty so that owners faced with this problem won't be left standing in the dark footing the bill for an admitted design defect.

Sorry guy's for not getting back to everyone.
I am gutting my house. New pluming, wiring, Drywall, all new insulation, adding a bathroom, expanding a dormer, and all new trim inside and outside.

OK back to the Head Gasket suff.

Another tech (#1 golden boy) did a set of head gaskets and installed 20 TimeSerts on a 97 Deville last month. I would say that this tech is an average tech. I would not let him touch one of my cars, but he turns the most hours in the shop. Management like him and the help him out all the time. On this old slug the stock TimeSerts pulled out. The boss came to me for help. They wanted Norm's inserts. I didn't have any and it takes and act of god to get a check for something. This left us with using a PO. My boss bent over backwards to get this tech a set of BIG inserts. Myself and the #2 golden boy had asked for the BIG TimeSerts a couple of times before and never got them.

Anyway the Big Serts are a lot different then I thought they would be. I will get some pictures.

After seeing them I would say that they are worth a try. I would not try to install the original TimeSerts in a 1993 to 1999 block. The originals TimeSerts just don't fix this issue.

The BIG TimeSerts still have a 1.5mm thread pitch on the outside. This is good and bad.

Good: If the inserts turns when you are torquing the head bolt by angle the thread pitch will keep an even torque

Bad: The thread depth is still shallow and doesn't have the bite that Norm's does.

where can you get the "norms " inserts and the stainless steel gaskets??

Also to the guy that pulled the engine out the top, was it worth it?

where can you get the "norms " inserts and the stainless steel gaskets??

Also to the guy that pulled the engine out the top, was it worth it?

Norm always has them on Ebay
Search: NORTHSTAR ENGINE NS300L HEAD BOLT THREAD REPAIR KIT

The Head Gaskets come from. I would call them to make sure they fit the application. I know they fit 93 to 99. They may have other years also
http://www.cometic.com/images/domesticauto.gif (http://www.cometic.com/domesticauto.aspx)

The Final Fix for Cadillac performance goals...

http://www.tallantsauto.net/572cadi.htm

All it takes is $$$$$$$$$$$$$$$$$$$$$

(sorry... off topic)

But an injected LSX conversion would save a lot of those $$$

Thanks AJ. I got the norms inserts and am halfway through installing them. I ended up with Fel-pro Headgaskets. I've always used felpro gaskets and trust them.

By the way the FSM is wrong on the torqe for the m6 headbolts (by the timing chains). it says 106 lb ft! more like 10. I need to get 3 new ones now. I should have known. Seems really obvious now.

Thanks AJ. I got the norms inserts and am halfway through installing them. I ended up with Fel-pro Headgaskets. I've always used felpro gaskets and trust them.

By the way the FSM is wrong on the torqe for the m6 headbolts (by the timing chains). it says 106 lb ft! more like 10. I need to get 3 new ones now. I should have known. Seems really obvious now.

That should be 106 lb inch

Would it be a good idea to make a Sticky out of 97EldoCoupe's 'studded block' repair thread?

As good as the Norms inserts sound, this sounds like a pretty kick@ss solution as well.

Photo of one of my studded blocks - this completely eliminates the need for inserts...

http://www.northstarperformance.com/img/studs3.jpg

This can be done even on engines that have had timeserts before. They are custom machined.