26th Jun 2009, 13:39

It's not headgaskets that leak but head bolts pulling out of the block. This happened to my '97 Eldorado at 91,459 miles. I maintain my car BY THE BOOK and as far as I'm concerned the head bolt issue is an engineering mistake by GM. I still own the car, have added 25,000 miles to it since repairing the block myself, It's a terrific ride and I have no plans to get rid of it.

2nd Jan 2010, 00:11

The NorthStar has the same inherent problem as the HT engines that preceded it. The cast iron cylinder liners are the main problem of the head gasket failure on the NorthStar and any other aluminum block engine. The two metals expand at different rates under the heat of combustion, and this tears the head gasket, which results in leaks. Instead of GM and other manufacturers using better gaskets, they either let the owner deal with a blown head gasket $$$ or recommend the use of stop leak. The stop leak is just a temporary fix to hide a big problem. GM probably intends on the owner trading the car in as soon as the trouble starts. This keeps the $$$ from new car sales rolling in.

2nd Feb 2011, 11:49

Bought my Eldorado in 1998, and had nothing but trouble. 2 rebuilt motors later, and I'm ready to junk it. My car has 40000 original miles. Spent 5500.00 this last time, and was told I don't drive my car enough.

3rd Feb 2011, 13:24

Two rebuilt motors?? Why did you have to rebuild the motor on a car with only 40,000 miles? That's the real question...

10th Mar 2011, 14:39

I work at an auction house where we have happened to repo many of these vehicles. I'd say that a good 70% of the Cadillacs with the Northstar engine have had the coolant leak from the intake manifold or head gasket. This is what you get when you pay that extra money for what you think is luxury. I'd definitely be staying away from these engines.

However, the newer Cadillac V8 (5.7 / 6.0 / 6.2) engines are much more reliable. We have about 40 trucks with the same engine block that receive well over 100k miles per year and hardly ever break down. We usually retire them at 200k+ miles.

Honda/Toyota vehicles are a much better investment if you're looking for that fuel economy and life long reliability.

21st Mar 2011, 10:58

I have an 1998 Eldorado, in which was a great riding car until it start overheating! I've heard it all from heads to being just a plainly piece of crap! However, my caddy shows no signs of cracked, leaking, or blown anything, it's more of a pressure build-up coming from somewhere.

It rides good without overheating like it has a mind of its own, then, out of the blue, after day 3 or 4 with no problems, it overheats!

Any suggestion? I need answers.


21st Jul 2011, 14:54

If you replaced the Dexcool that was used stock in 97-99s and some '96s, chances are the HG would still be fine.

Dexcool is corrosive by nature, and will cause similar issues in just about any car.

$3000 is a bit on the high side for this repair as well. You can have it done properly for less.

Many other cars have repairs that are far worse.

21st Jul 2011, 14:57

Do NOT replace the coolant with Dexcool. Dexcool is solely responsible for 90% of N* HG failures because of its corrosive nature!

But replacing the radiator fluid often, with something other than Dexcool is excellent advice.

24th Sep 2011, 00:46

Just a note on a comment on the engine. If you have the Northstar, both the block and the heads are aluminum. On the earlier 4.X engines, the block was aluminum, and the heads were cast iron.

26th Apr 2012, 14:13

What would be the best type of coolant to use in the 98 Northstar engines?

24th Dec 2012, 00:41

Accelerating a car is not "abuse" ---- ESPECIALLY in a high priced sports/luxury car. The car should have been tested better at the factory before Cadillac sold it.

No, not "all" cars blow head gaskets after being accelerated in a brisk manner. In fact, it is VERY rare. Cadillac admitted to the problem. They did NOTHING about it, and did NOTHING to help their customers who purchased the models with the faulty engines.

15th Mar 2014, 23:08

I have a 2002 Eldorado with 64000 miles with no problems. The local GM place does all my service and maintenance. I receive great comments on my car everywhere I take it. I would not sell it for any amount.

26th Jan 2015, 10:49

Use the HOAT Coolant. The orange stuff. Zerex I believe it is called.

26th Jan 2015, 23:32

Dex-cool is the word you're looking for. Orange, and awful stuff that almost put GM out of business.

12th Apr 2017, 15:19

The Northstar is well known for having several engineering mistakes; look around Cadillac forums or ask a mechanic and you'll see.

Not least of which is too small bolts used to hold the head on the engine, causing repeated complaints of head gasket failure.

Especially with a famous problem like that, you should know what you're talking about before you accuse him of blowing up his car.