: One Dead Deville 1999



Free Tibet
01-23-04, 02:05 AM
Today my service manager gave last rites to my '99 Deville with 84,000 miles. I have been trying to get Low Coolant level fixed. After I completed this month's fixes (replaced radiator, replaced heater core, replaced my second battery) I was told that either one or both of the head gaskets may be leaking as the cause of the low coolant level. The front head gasket, water pump, and radiator drain plug were all replaced at other times as the cause of the low coolant level. But now they say it could be more than gaskets, it could be the bolts in the block that hold the head. If so I need a new engine. Anybody got an opinion how to get Cadillac to own up to the problem? Would you replace the head gaskets and hope for the best or junk the car? Help!

Playdrv4me
01-23-04, 03:54 AM
Today my service manager gave last rites to my '99 Deville with 84,000 miles. I have been trying to get Low Coolant level fixed. After I completed this month's fixes (replaced radiator, replaced heater core, replaced my second battery) I was told that either one or both of the head gaskets may be leaking as the cause of the low coolant level. The front head gasket, water pump, and radiator drain plug were all replaced at other times as the cause of the low coolant level. But now they say it could be more than gaskets, it could be the bolts in the block that hold the head. If so I need a new engine. Anybody got an opinion how to get Cadillac to own up to the problem? Would you replace the head gaskets and hope for the best or junk the car? Help!

Oh my... I certainly wouldnt junk it but I dont know if id put much more into it. Maybe do the rear head gasket and cut your losses after that if that doesnt work, possibly sell it. Or perhaps there is a common issue someone here knows about

Big Jim
01-23-04, 06:26 AM
They are not just pulling your leg about the headbolts. There has been some problems with pulling the threads out of the block. Enough that there is a kit to put inserts in all the holes. From what I've heard, it should be done if you take the head off for any reason. If they didn't do it on your front head when they had it off, raise all kinds of hell and maybe they will give you a break on the whole job.

zonie77
01-23-04, 03:46 PM
I've done the headgaskets on a STS. The threads strip out of the block and there is a repair that can be done to the block. See: http://www.timesert.com/
The kit is a little over $300 although there may be some used ones floating around.
If the threads were bad the first repair was a waste of time and money. Since this is an authorized Caddy repair I can't believe a dealer doesn't know about it. It's possible they felt the threads were still good. I've heard that the threads on newer N* don't pull out but I am not sure what cutoff is used.

To do the rear head the engine has to be removed from the car. There are threads about this so I won't go into it. It is a long process.
To timesert the block and replace the gaskets would be expensive but consider what the car is worth now(not running) and what it is worth in good condition and it may be worth it.

BeelzeBob
01-23-04, 11:56 PM
Today my service manager gave last rites to my '99 Deville with 84,000 miles. I have been trying to get Low Coolant level fixed. After I completed this month's fixes (replaced radiator, replaced heater core, replaced my second battery) I was told that either one or both of the head gaskets may be leaking as the cause of the low coolant level. The front head gasket, water pump, and radiator drain plug were all replaced at other times as the cause of the low coolant level. But now they say it could be more than gaskets, it could be the bolts in the block that hold the head. If so I need a new engine. Anybody got an opinion how to get Cadillac to own up to the problem? Would you replace the head gaskets and hope for the best or junk the car? Help!
Your frustration should be aimed at the dealer and the shotgun approach that they are taking to fixing this. They are just spending your money and replacing parts willy nilly and running out of options.

A loss of coolant should be relatively easy to deduce by pressure checking the system and finding the leak point. Obviously they are happier spending your money and shot gunning it rather than doing the proper detective work...and you are playing along.

Leaking head gaskets, if that is the problem, are very very easy to positively diagnose in several ways:

The simplest is to start the engine cold with the cooling system full and the pressure cap off the surge tank. Watch the coolant for excessive, steady bubbling indicating a compression leak.

The spark plugs can be removed and each cylinder in turn pressurized with shop air at 120 PSI using an old spark plug shell as an adapter. Watch the cooling sytem for bubbling indicating a compression seal leak. Positive test. Never fails to either find a leaking head gasket or prove that they are OK.

With the spark plugs out and the cooling sytem full pressurize the cooling system with a cooling system pressure tester pump. Pump it up to 15 PSI and let it sit for 2-3 hours. Keep pumping it up if it looses pressure and watch the exterior for leaks. After a couple of hours, spin the engine over with the starter and watch for coolant coming out a spark plug hole. Bad sign if it does...but a sure way to find a leaking head gasket if it is contributing to the loss of coolant.

Drain the cooling system and pressurize it to 15 PSI again with the pressure tester. Stick a 3/8 hose down the spark plug hole in each cylinder and stick the other end in your ear like a stethascope. If you can hear hissing of leaking air...chances are the head gasket is leaking.


Maybe you should print these procedures out for your mechanics that can't find the leak and are blaming the head gaskets so they can get their shit together and solve the problem.

If the head gaskets do have to be replaced, all is not lost as the head gaskets can be replaced with the engine in the car. If a head bolt hole is stripped or extra insurance is wanted the head bolt holes in the block can be easily repaired with the special Northstar head bolt "Timesert" kit. Use only timeserts and use the special Northstar kit and inserts. Contrary to advice above the timeserts CAN be installed in all head bolt holes, left/front and right/rear cylinder heads. There are many testimonials by individuals that have done the job on the www.caddyinfo.com (http://www.caddyinfo.com) forum. Pulling he engine is one way to do it but is NOT necessary.

I hate to rant about crummy mechanics but to have a coolant loss problem and not be able to find it is pretty basic. Replacing parts until the problem disappears is the worst approach imaginable as you are experiencing. Find some qualified mechanical help.

Just as an afterthought....did you try putting the GM coolant supplement pellets/sealer in the cooling system as recommended in the service manual?? The GM coolant supplement/BarsLeaks "golden seal" powder is VERY effective at eliminating nuisance leaks and coolant loss and was factory installed in the Northstar as it is also used in MANY other aluminum engines to guard against porosity and such. I would try the supplement/sealer even if a head gasket is suspected as it can often stem coolant loss at a head gasket leak until the gasket becomes so unservicable that it starts to leak compression into the cooling system.

Another item to check if there is a mystery coolant loss is to look into the valley of the engine...under the intake manifold. You could remove the intake to do this or simply look straight down into the valley directly behind the power steering pump. The valley on the Northstar is dry and the coolant jackets for the valley walls. If there is a porosity or cold shut in the casting (a casting "defect" but harmless...other than the nuisance leak) of the water jacket walls then there can be a leak into the valley that is nearly invisible and could go undetected. The coolant seeps into the valley and evaporates unseen so no-one knows where it went. If there was a porosity and the factory application of the sealant was sealing it up all this time the sealant may have just lost it's effectiveness over time (it needs to be replenished too) so a simple add of the sealant would solve the problem.

Good luck and post results.

jupiterpbc
01-24-04, 02:12 PM
Hello "Free Tibet"......I have a similar dilemma, but had anticipated the expense when I purchased my car. Consider the following and it may make "cents" in your situation.

I purchased my 1997 Deville in 10/03. It had 143,000 miles and I paid slightly less than $4,000 for it. It's interior and exterior is a solid 8 on a scale of 10. I have never been overly concerned about a high-mileage car purchase provided the chassis and interior were in good to excellent condition, which is usually indicative of highway miles, because they are relatively inexpensive and I factor in the cost of a low mileage engine replacement when I do finally purchase a car. My car ran flawlessly when I bought it, however, I have put over 13,000 miles on it since then and it has developed a progressively worse coolant loss problem and I am now faced with the engine replacement issue. There is no doubt in my mind that it is either/both a bad head gasket or in dire need of a time-sert application since the engine will produce steam in the exhaust until it reaches operating temperature, additionally, I have pulled all spark plugs and have determined that only the right bank is affected at this time. I still get 23 MPG on the highway and that is down from 27 MPG.

Now for the economics lesson.....I have located a 1999 N* w/ 34,000 miles on it and the digital instrument cluster from the same car for $1,750 and arranged to have it swapped for $600 for an aggregate amount of $2,350. Add that to my original purchase price of $3,900 and I will have $6,250 into a 1997 Deville with 34,000 miles with the chassis having 156,000 miles. Now, could I get $6,250 for the car if I were to sell it? Maybe, but rather unlikely. Could I buy another 1997 Deville with 34,000 miles on the engine/chassis? Absolutely not, unless the seller had a recent lobotomy. Can I be assured that I won't have a head bolt/gasket issue arise before I sell? No, but I'll bet I won't with meticulous maintenance.

What really irks me is Cadillac continued to manufacture the N* throughout the 1990's with full knowledge of this MAJOR design flaw. My next car to replace this one may be yet another Caddy, but you can rest assured I will be 100% convinced they have solved this problem before I do.

Hopefully this has provided you with some "food for thought".