: 4.9 blown head gasket

Eldorado guy
01-06-11, 03:08 AM
Hello everyone. I have a quick question. I found a 1992 Cadillac Eldorado with the 4.9L with 100,000 miles. The problem is that it supposedly has a blown head gasket. The car is at a tow yard and from the couple pictures I can see, it looks to be in really good cosmetic shape. I don't know about the interior yet.

I was wondering how hard it is to replace the head gaskets on these engines. I've looked around, but I can't find a whole lot of info. Can you replace them with the engine in the car? Must it be timeserted? I know it must be fairly difficult due to the transverse engines.

I wouldn't even consider this normally, but the car looks nice and they only want $800 for it. It's been there for a while too, so maybe I could get it for an even better deal if I bring a trailer so they don't even have to touch it. The car is an hour and a half from me, which isn't too bad, but I don't want to waste the time going there if it's not worth it and I definitely don't want to start something that I can't finish. I will only consider it if it's in as good of shape as it looks. I have replaced head gaskets before and I've done lots of previous work on engines, but the whole transverse thing will be a whole new experience for me. Any ideas are welcomed.


P.S. After the research, I'm wondering if it could just be an intake manifold gasket leak.

01-06-11, 07:53 AM
Head gasket failure is quite rare on these engines but not unheard of. I would almost doubt it, but if the cooling system sprung a leak and somebody kept driving it a head gasket could fail. It would be easier to find another cadillac with a good 4.9 to put in it. I almost bought another 92 deville last week for $400 with 105,000 miles on it. I had to pass because the interior was so thrashed it was depressing. It would have been a good engine donor; or maybe not since the PO was obviously a slob.

My 92 Deville has 195k on it and runs flawlessly and still uses hardly any oil. I am looking for a nice 92 Eldo to put my engine in. I'll bet you can talk them down on that car; offer them $500 and I'll bet they take it. If it was in Maine I would be interested. I'm a sucker for a clean interior and rust free body. If I have that to start with I don't mind sinking more money into it. If the interior is thrashed then it has been abused and should be put down.

Eldorado guy
01-06-11, 01:58 PM
I totally agree with your interior statement. My 1980 Eldorado with the triple yellow color combination was spotted in a Salvation Army for $500. What really got me was the interior- it was almost mint. The paint was faded and there were small amounts of rust, but overall the body was in good shape. It ended up needing a new intake valve on #1, but that was because the Salvation Army didn't take the necessary precautions before starting a car that sat for 7 years. It turns out the car was owned by an elderly couple all its live who loved it like a child. So, a good interior and a straight body (with all the same color panels :histeric: ) really tells you something about how the po treated the vehicle.

The vehicle is in California, so you would be shipping it a long ways!

Is there a way that I can truly determine if the head gasket has failed while I'm there (without doing a compression test)? Should the coolant reservoir bubble or something? There's also a 1995 Riviera supercharged there listed for $1200 (down from $1500) with a blown head gasket and a new tranny, but I'm betting on it having tons of miles. If it doesn't have too many miles, I bet I could snag if for $800-$900 cash. The thing is with that car, the 3.8L engines don't usually blow head gaskets, but they blow lower intake manifold gaskets, which would be a pretty easy fix on a car that cheap...

the recluse
01-06-11, 09:12 PM
To replace the head-gasket you need to remove the motor, and yes, the block does have to be heli-coiled. The gasket kit costs around $275 and the Heli-Coils and tools around $100. You'll probably want to change the water pump while the motor is out for another $50. MOST of the time the motor mounts on these motors are brutalized due to the torque and need to be changed, something else to look at while the motor is out. There are four total and cost $200-$250 for all of them.

Depending if the heads were damaged or not can add a lot to the cost of the fix also. Head/valve job can run upwards of $500 if no valves or guides need replacing and only the heads need decking and the valves reseated.

All that is only IF the car wasn't driven extensively with a bad head-gasket. If it was you can factor in a whole engine rebuild with the cheapest kits running around $1100 and you still need machining. You can get complete engines for around $3000-$3200.

Those are, in a nutshell, your options for the car. If at the most you had to put a new motor in, you've still out priced the car itself. HOWEVER, you have a damn nice car for around $4000-$4500. Happy hunting.

01-17-11, 08:15 PM
As someone already mentioned a blown head gasket is rare on a 4.9, might be worth the cost of a test kit to check for gases, maybe it's not a blown h/g, I've had 3-4.9's over the years and their a great engine.