Root Cause of Head gasket Failure and a Fix?

[tateos]

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?

[JC316]

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?

[AJxtcman]

Originally Posted by tateos

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

Originally Posted by JC316

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.

[NHRATA01]

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.

[JC316]

Originally Posted by AJxtcman

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.

[SmoothTS]

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?

[dwight.j.carter]

Originally Posted by SmoothTS

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.

[dwight.j.carter]

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 ?

[Raze]

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...

[Ur7x]

Originally Posted by dwight.j.carter

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.

[aarcuda]

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!!

[AJxtcman]

Originally Posted by Raze

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, unscrew, or the worst partially unscrew

[AJxtcman]

New pictures
This is Highline Cady's 2003 DHS

This is the head gaskets. It looks pretty good.

[AJxtcman]

These picture shows some signs of bunching up.

[AJxtcman]

This is the head bolt conversion

Stock up to 2004


As you can see they came out clean, but all the threads were pitted.


2004 bolts


Comparision of the pre 2004 and the 2004 and up.





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