95 sts 159000 miles blown head gasket!!!!!!

[firemistred95]

While pretty sure its a blown head gasket. It idles really rough, but white smoke doesnt come out till it has ran for a minute. I cant smell coolant in the exhaust or surge tank ,but im going to do a drip down test this weekend. BUT REALLY What else could be beside a blown head gasket???? I was hopeing maybe bad plugs or wires? Can ya think of anything else it may be?? But my real question is it worth taking the engine out ,getting the head gaskets replaced, more then likely havin to re-machine the heads??? local cadi dealer told me 4000 dollars and NAPA said 2000 was a good starting price!!!!! I also heard it was useless trying to repair a overheated alumanium cadi engine, a friend said it would still have problems after remachineing the heads. Then someone told me for a new engine the vin codes on the motor have to be the same as the cadi computer. IS THIS TRUE????? whenever i call for a motor they just ask for the 8th vin which is 9, so as long as i match the vins up a,95 sts motor should bolt right in .Was my thinking, am i wrong?

[firemistred95]

also ...My MPG has gone all the way down to 10.5, when i bought the car i think it was at about 12.6 atleast.cant remember very well.

[Ranger]

You will have to use a '95-'99 engine. You will have to stay with a Vin "9" engine. Unless you overheated it badly, it probably only needs to be Timeserted and new gaskets. I have not heard of many people machining the heads.

[EcSTSatic]

Don't jump to conclusions. (Over)Reactor yanked his head thinking he had a bad gasket and all he found was shorted out injectors.

Are you losing coolant? That would be a major clue. Did you actually over heat it or mention it in passing? You mentioned gas mileage. White smoke can be a very rich fuel condition. If you are not losing coolant, check your fuel system out.

[firemistred95]

Yes I had a plastic tank radiator leak on the passinger sideWhen i bought it then I put some bars leak in it and it drove without leaking badly (or so i thought) for 190 miles.The morning after i believe I overheated it , it said low coolant level. So Im pretty sure I overheated, not sure how badly. Also could the bars leak do anything bad to the engine? It still looks like there is some in the surge tank.

[zonie77]

There are 3 tests to check for blown head gaskets. In order of cost and accuracy they are:

Coolant contamination test, very inexpensive, looks for hydrocarbons in the coolant but can be misleading.

Compression test, easy to do, not very accurate, doesn't pick up small leaks (which still cause overheating) well.

Cyl leakdown test, pressurize the cyl and watch for air bubbles in the coolant.
More time consuming and expensive but more accurate.

Plugs and wires don't cause overheating!

You should get the radiator repaired or better yet, replaced first. Do any, or better yet, the cyl leakdown test next. After you fix the leaks see if you are losing coolant. The barsleak should go in the radiator hose, not the surge tank. That's why it's still sitting there.

Read the head gasket thread in the tech section, look at the link for the timeserting job.

The only thing you probably will need (if it's actually head gaskets) is timeserting and new gaskets. The block and heads are probably in good condition. Caddy did a great job designing heads. They don't warp the first time they overheat like so many cheap engines do.

The 9 and Y engines have different power curves and gearing. You should keep them matched, so if you replace the engine keep it a "9".

Unless you are really beating on it constantly you should be getting better gas mileage than that. Read the FPR thread in the tech section and check that right away.


Get the radiator fixed first before thinking about replacing the engine!

[Eldyfig]

You would know if you overheated it. You have a 95, so you should have a display under your speedometer, correct? Your car would go into limp home mode if you loss enough coolant to overheat it. You would have seen this message come up in the display.

Bars Leak is not bad for the engine. You need it. However, like Zonie mentioned, the Bars Leak or coolant tabs go into the bottom radiator hose. If it is in the surge tank it isn't able to circulate through the engine.

Ranger, the 95 is an OBD I car isn't it? Can you swap out the 95 northstar with an engine controlled by an OBD II PCM?

[Pjazz]

Man! 159,000 miles! Hopefully you didn't pay to much for the car. With that many miles on a caddy you will probably be looking at other major issuses. With of all the complex electronics on the car it's only a matter of time before something else goes out. I personally would get rid of it.

[Eldyfig]

Those miles are climbing up there. But I have seen other members on this forum clock in more miles than that on their caddies and still running strong without major griping.

I have 118k on mine and expect alot more.

[Ranger]

Originally Posted by Eldyfig

Ranger, the 95 is an OBD I car isn't it? Can you swap out the 95 northstar with an engine controlled by an OBD II PCM?

Ahh, Good point. I think I recall Bbob saying '95-'99's are compatable so I would say yes. The '93/'94's use MAP sensors vs MAF on the '95 - '99's. I think that is the big difference so my guess is yes but don't take it a gospel.

[WarrenJ]

Originally Posted by Eldyfig

You would know if you overheated it . . . . Your car would go into limp home mode if you loss enough coolant to overheat it . . . . You would have seen this message come up in the display.

Been there/Done that when the waterpump went south.

The "STOP ENGINE NOW" Warning will display on your DIC. Did it? The PCM will engage "Limp Mode." Did it?

Regards,
Warren

[Raze]

Hey I had a similar issue, and it turned out to be a loose intake manifold with a vaccuum leak.
I did the hydrocarbon test, it showed slight but not full turn, and was told it was in the beginning stages of a blown headgasket by Caddy dealership who wanted 7k for the engine swap...

I then had the compression test done by my mechanic who had good compression on all cylinders....

I got the CHECK COOLANT LEVEL, and found I had a cracked radiator side tank, got that replaced but the rough idle on start was still there, no smoke coming out the tailpipe either, and no smell of coolant.

FINALLY I did the leakdown and it was negative, at this point I had no idea as I had just done a tuneup, checked for leaking injectors and FPR, everything checked out.

I had my radiator finally changed out, I did thermostat and surge tank pressure cap (the old one was blowing off at 10psi, not the 15psi called for in the factory service manual. My mech (who replaced the radiator) found a vaccum leak around the intake manifold.

I bought new manifold gaskets, pulled the intake off, cleaned everything, put new gaskets in, retorqued manifold, and voila, problem solved...

Don't worry too much, I did and it was alot of unnecessary stress...

[SHANOGAY]

I've been told my '99 Deville probably has a cracked head gasket. They said coolant is leaking into the engine. It gets hot really quickly. The thing is they say it will cost me $2,000.00 just to confirm that the head gasket is the problem, because of something about removing the cradle (?). If that is what it is it will cost about $4,000.00 to fix. If not, I'm still out the 2 grand just for a look-see. Is what they are telling me right? Isn't there any other way to check? It's got 115,000 miles on it. Is it worth it?

[Raze]

Shano,

Would you be having a shop do all the work? If so 2-4k just to have the main headgaskets replaced is pricey & a crapshoot UNLESS TIMESERTS are installed in which case it's a fair price. The spacing and location of the hads makes it just about impossible to do this job in the car, so the easiest way to do it is to drop the front engine cradle which includes the front subframe, suspension & wheels, transmission, and engine. The job at that point is child's play from what I understand, maybe someone who's done the repair would like to weigh in.

Now, with the mileage on the engine and the cost of just having this repair done you can always look into a new or remanufactured engine. GMGoodwrench engines run 5k without install, and no core charge so you keep your old engine/sell it off on ebay, for about the same price you can get a Jasper remanufacture (it has a 3 year/75k mile warranty as opposed to GMGoodwrench's 3 year/50k mile warranty and are a little cheaper to install since there are certified jasper installation shops all around the country, check website www.jasperengines.com). I ran through all of this when I thought my HGs were gone and found a local shop that would do the full Jasper replacement for 6k on the dot including new belts & pulleys.

Now is it worth it? I don't know, 2-4k for a repair that will easily outlast the engine, or 5-7k for a brand new engine, or a more expensive new car, or a used car with it's own set of problems is debatable. It's a hard choice but I do alot of highway commuting and feel alot better & safer in my 98 ETC than any of the cars I test drove to replace it. Goodluck

[Ranger]

$2000 to check for a bad head gasket? Give me a break. Find an honest mechanic. Shouldn't cost more than a hundred bucks or so. There is no need to drop anything to check for a gasket leak. All they have to do is pressurize the cylinders with shop air. They're throwing out the bait and hoping you'll bite.

You may infact have a bad head gasket and if so, it will take dropping the cradle to remove the drivetrain to repair it and $3000-$4000 seems to be the going price but they are ripping you off on the diagnosis.