Root Cause of Head gasket Failure and a Fix?

[submariner409]

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.......).

[patterson]

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.

[Johnson's91Coupe]

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.

[AJxtcman]

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.

[davz]

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?

[AJxtcman]

Originally Posted by davz

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

[ronbo]

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 $$$

[davz]

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.

[AJxtcman]

Originally Posted by davz

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

[C0RSA1R]

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.

Originally Posted by 97EldoCoupe

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.

[bpierson]

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.

[davz]

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.

[bpierson]

Originally Posted by davz

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.

[SCOTT2325]

I have a 2001 SLS with 112k miles on it i guess this could happen to me at anytime now ?? I think i'll trade it in very very soon i have only had it about 6 weeks but after reading this i have stopped driving the car i have a car cover on it in my carport now .

[submariner409]

Post-2000 Northstars are not as prone to bolt failure as the late 90's engines. There were quite a few mechanical changes during 2000-2001. Drive it.

See my post in the companion sticky.....these questions belong in the main threads, not the stickys.