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199K views 179 replies 70 participants last post by  Pht 
#1 ·
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


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


This is a Norms insert. This will be another part of this discussion later.


This is the two of them side by side






 
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#73 ·
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.
 
#77 · (Edited)
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! ?


 
#79 ·
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.
 
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#85 · (Edited)
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?
 
#80 ·
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.
 
#84 ·
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.
 
#86 ·
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.
 
#91 ·
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.......).
 
#92 · (Edited)
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.


 
#93 ·
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.
 
#94 ·
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.
 
#96 ·
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
 
#98 ·
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.
 
#100 ·
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...



This can be done even on engines that have had timeserts before. They are custom machined.
 
#101 ·
We owned a '94 SLS that ended up with a cracked block. Traded that in for a 2000 DTS (we are 2nd owner) which has been at the dealers for going on 3 weeks now. Only message we got was coolant was low. We took it in and had them look at it. They said it might be head gasket blown, later they said 3 loose rear engine bolts and not head gasket, later they said no its a crack on the engine block.
So I asked some questions...

Did you magnaflux engine? no was visible

Was there coolant in the oil? no visible coolant in oil

Is the water jacket solid? no thats where it is leaking from

By what cylinders is the crack? if your sitting in the driver seat it is the back left cylinder.

Now they told me that all these where unusual for a Cadillac that has only 57k miles on it (2000 DTS). We also baby our Caddy's.

From what I have been reading here... cracked heads, gasket leaks, etc... seems to be the norm for Cadillac? Cadillac it's self refuses to do anything to help with the cost of repairs. The dealer quoted over 6k to put in a "new" used engine. So we went with the cheaper option of welding the crack. How long will weld last? Any input or assistance will be appreciated.
 
#102 ·
How long have you had the car?

How long do you want to keep the car?

If you do the weld, sell it soon or trade it in. There may be more cracks on the horizon, or if thhey don't insert the bolt holes, the headgaskets won't last.

If you go with the new engine, keep the car.

I would go with the new engine if you have the money.
The remanufactured engines already have the timeserts in them, and are about 3600 dollars on ebay. Or a new engine is just that - NEW.
 
#103 ·
How long have you had the car? going on 2 years.

How long do you want to keep the car? We still making payments on it, so at least another 3 years.

If you do the weld, sell it soon or trade it in. There may be more cracks on the horizon, or if thhey don't insert the bolt holes, the headgaskets won't last.
I talked to the tech and he said they will put new bolts/timeserts in and they are going to get me a price on a multilayer headgasket.
If you go with the new engine, keep the car.
They want to much for a 65k mile motor and install (the new engine price is just insane), we opted for the weld.
I would go with the new engine if you have the money.
The remanufactured engines already have the timeserts in them, and are about 3600 dollars on ebay. Or a new engine is just that - NEW.
Please see notes above.
 
#106 ·
I would sell it ASAP if I was you. My '99 STS has 114K on it and needs a head gasket. I just bought it a year ago with 112K on it for $7500. Now I can only drive it to places within 5 miles of my home or it will overheat. The Northstar engine is a piece of shit. SELL IT ASAP!!!!
 
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