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