: 1999 Deville Headgasket - head job or total overhaul ?



Northstar125
06-20-14, 05:58 PM
So I'm looking at purchasing a 1999 Deville with a bad headgasket and I'm trying to total up the parts cost of what all I'll need.

Obviously all the top end gaskets and a set of studs from Northstarperformance. But what about the lower end? I've head some horror stories when pulling the midcase apart then new bearings, crank, etc are needed.

I'm very skilled but have never actually rebuilt an engine or went this far in depth (especially on a N*) but I think its worth a shot.

Pretty much just looking for opinions on the lower end. Pull it apart or leave it? I'd prefer not to have oil leaks but I'm not going to spend another $1,000 in parts if that is what it needs.

arctic_man
06-20-14, 08:18 PM
So I'm looking at purchasing a 1999 Deville with a bad headgasket and I'm trying to total up the parts cost of what all I'll need.

Obviously all the top end gaskets and a set of studs from Northstarperformance. But what about the lower end? I've head some horror stories when pulling the midcase apart then new bearings, crank, etc are needed.

I'm very skilled but have never actually rebuilt an engine or went this far in depth (especially on a N*) but I think its worth a shot.

Pretty much just looking for opinions on the lower end. Pull it apart or leave it? I'd prefer not to have oil leaks but I'm not going to spend another $1,000 in parts if that is what it needs.

How much work do you want to put into it? Search this site, there is a thread by Bill Buttermore. He did everything to the engine. Completely refreshed it. He has many pictures, and cost breakdown. In addition to cost, it will take much longer if you choose to reseal the half case.

When I did mine on my 99, I had studs, valve cover gaskets, water crossover gaskets, an oil level sensor that I broke, head gaskets, and I think that was it.... But my half case is not leaking. Total cost came somewhere around 600.

In addition to the parts, you need the tools to do it. A good 1/2 socket set, and a breaker bar. Maybe some swivel sockets, extensions, and so on. Many users here have dropped the cradle from the bottom. You can do it with a large enough jack, but a cherry picker or hoist is most often used. You will need one of those. If you wish to do the half case, you will also need an engine stand. One large enough to support a V8.

But do some research on this site. You will find a lot of guides on how people did it. You just need some tools, the right attitude, and know when to walk away and call it a day.... Oh and beer... lots of it.

basscatt
06-20-14, 08:54 PM
I'm very skilled
but have never actually rebuilt an engine
or went this far in depth (especially on a N*)
but I think its worth a shot.
you might be biting off a LOT more than you can chew -

many professional mechanics will not touch a Northstar motor -
too complicated - and the job takes too long -

maeng9981
06-21-14, 08:21 AM
If you have halfcase leaks, then definitely open up the lower half and replace things.

Basically you'll need new main bolts (or you can go with main studs from Northstar Performance). Rod bolts and bearings if you're going to pull the pistons. Why not replace the bearings when you're in that far deep? You can reuse the crankshaft though, that one's bulletproof. Oil manifold, rear main seal, etc. The rear main seal would require a special tool but there's always a workaround.

I did an overhaul not too long ago on a 99, it cost me about $1600 total (and that's including a rebuilt alternator + a/c compressor + dryer. Actual parts cost is around $1200)

If you do tackle on this project, I believe there are a lot of people here who can help you with every step. It's a good experience for sure. I did it. That means you can.

Submariner409
06-21-14, 09:13 AM
Good sockets, wrenches, and torque wrenches. Various solvents and cleaners. DO NOT - EVER - get anywhere near an engine with a ScotchBrite pad. Patience. Time. A mechanical eye. You will NEED a real GM/Helm service manual for some procedures and torque specifications. Read as much of Cadillac Tech Tips as you can wade through as well as this forum. Study the Cadillac Technical Archive way up ^^^ in the black bar. Read the sticky posts at the top of any forum of interest. There are new procedures for resealing the halfcase and oil pan.

The lower end in any unknown used engine is a crapshoot - you have no idea of the maintenance history so you would probably be better off doing a full overhaul nstead of just head gaskets. Now we're talking money - the crank does not get reground: It gets replaced if necessary. Cylinders do not get honed or bored............. this could go on and on, but it's all in the GM service manual for the particular car/year/engine. Some have put a Northstar back together with very little attention to detail - however, I don't recommend a half-assed approach. Do it right or don't even start.

There are two engine versions, and which parts you need depends on the model of Deville you're buying.

04GrandAmGT
06-23-14, 11:06 AM
Full Stud kit - $549.00
we do offer a full gasket kit from oil pan to intake gaskets + Coolant crossover gaskets - $449.00
Main stud kit - $189.00

all prices include Xpresspost shipping (2-4 Business Days)

if you have any questions at all call me at 1-888-800-9470 or email info@northstarperformance.com and i will be happy to assist.

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9/10 times the bottom ends of these engines are in well condition to keep using, like Sub says depends on how they serviced it, but you will know as soon as you split that half case how they serviced it by what the bearings look like.

Northstar125
08-23-14, 08:24 PM
Wel guys the car turned out to be complete junk. Had rust and cracked bumpers, busted windshield and nasty looking interior. And the guy told me it was immaculate....

But I will be learning the headgasket soon. I have TWO headgaskets I am going to have to replace now.

maeng9981
08-24-14, 03:14 AM
There are plenty out there in excellent condition that just have HG's gone (or as the owners think). For really cheap.