: Bad Thermostats or blown Head Gasket??? Help



Jays03dsg
05-31-09, 03:09 PM
Need help on this one guys. I drove my 99 devllle concourse from fort walton beach florida to birghmingham, ala. When i looked down and noticed my temp guage rapdly approaching peg. I immedately got to the side of the road and shut down the engine. We sat till the motor cooled off and added about 1/2 gallon of premixed antifreeze (2 days before i left ft walton my add coolant light came on and added the first half of the gallon).

I restarted and drive to the nearest exit and pulled off to let the motor cool for about 30 mins added another gallon and a half of straight water.

We started out again drove for about an hour watching the temp gage constantly. Everythng was fine for about an hour hen I seen slight heatng. stopped for about 10 minutes started out and ran for another 45 minutes. Stopped added about another 1/2 gallon of water and drove for about 40 miles and stopped when the temp guage started to clmb again at abou 55 miles from memphis. Finally gave up and called a tow.

Im thinking the thermostat is sticking but I am also told t is a bown head gasket.

Please. It would be helpul here your thoughts. Do you think it is a bad thermostat? The vehicle has 105k mles newer water pump and belt and new coolant reservoir.

Submariner409
05-31-09, 03:17 PM
Go to a NAPA parts store and get a "block test kit", $50 +/-. It contains a cylinder, pump, fluid for attaching to the top of the coolant surge tank in order to test the airspace over the cooolant for the presence of exhaust gasses = blown head gasket(s).

The coolant tank must be filled to halfway up, cold, which is the normal fill level, and the car must have been driven for a period of time in order not to get a false reading.

That test, and a prolonged cylinder leakdown test by your friendly local shop, are the best two ways to verify/rule out head gasket/s. Your symptoms are not normally present with a bad thermostat or water pump. :( :( :(

Jays03dsg
05-31-09, 03:25 PM
Thanks submariner, looks like a very expensive fix if head g blown. Any idea what I may expect to spend

Talamant3z
05-31-09, 05:41 PM
Go to a NAPA parts store and get a "block test kit", $50 +/-. It contains a cylinder, pump, fluid for attaching to the top of the coolant surge tank in order to test the airspace over the cooolant for the presence of exhaust gasses = blown head gasket(s).

The coolant tank must be filled to halfway up, cold, which is the normal fill level, and the car must have been driven for a period of time in order not to get a false reading.

That test, and a prolonged cylinder leakdown test by your friendly local shop, are the best two ways to verify/rule out head gasket/s. Your symptoms are not normally present with a bad thermostat or water pump. :( :( :(so the car is supposed to be off when testing?

Submariner409
05-31-09, 05:56 PM
Based on history in here and a conversation with a service writer at Fitzgerald Cadillac in Annapolis, MD, the range is frankly awesome.

Many local shops won't tackle the job due to the (relative) complexity of removing the drivetrain and the machine work involved. So.............

Jake, our Canadian Northstar Salvation Officer, using studs and accepted practice, will do the job on appointment for around $1750 US, IF you can truck the car to him. Your freight ticket. A Cadillac dealer will quote between $3,500 and $5,000, depending on their diagnosis and current labor rates. IF you can find a local shop willing to do the work (tedious, but not rocket science), about $2,500 - $4,000. DIY with Jake's studs and parts/gaskets......$1,600. (ALL of this is dependent on no other faults found.........) A 99 Northstar also stands a pretty good chance of experiencing the beginnings of cam lobe/lifter wear, eliminated by the 2000-up roller cam follower arrangement.

One of the conditions to a successful head gasket Northstar repair is the use of thread replacements to repair the failed block head bolt holes, the prime cause. There are 3 options: the Timesert inserts, the Norm's Inserts (beefier and better yet) and Jake's studs (the Ultimate). All 3 systems are within ~$200 in cost of basic materials.

Do some Scotch and water searching in here and in Deville to get a better picture of what you're up against.

(BTW, the car is worth saving - if not this current one, then a 2000 - 2004 model.)

talamant, The test analyzes the gasses present in the airspace over the coolant - the engine can be on or off - if combustion gas is present, it won't go away. When all else fails, read the instructions.

Talamant3z
05-31-09, 06:04 PM
Based on history in here and a conversation with a service writer at Fitzgerald Cadillac in Annapolis, MD, the range is frankly awesome.

Many local shops won't tackle the job due to the (relative) complexity of removing the drivetrain and the machine work involved. So.............

Jake, our Canadian Northstar Salvation Officer, using studs and accepted practice, will do the job on appointment for around $1750 US, IF you can truck the car to him. Your freight ticket. A Cadillac dealer will quote between $3,500 and $5,000, depending on their diagnosis and current labor rates. IF you can find a local shop willing to do the work (tedious, but not rocket science), about $2,500 - $4,000. DIY with Jake's studs and parts/gaskets......$1,600. (ALL of this is dependent on no other faults found.........) A 99 Northstar also stands a pretty good chance of experiencing the beginnings of cam lobe/lifter wear, eliminated by the 2000-up roller cam follower arrangement.

One of the conditions to a successful head gasket Northstar repair is the use of thread replacements to repair the failed block head bolt holes, the prime cause. There are 3 options: the Timesert inserts, the Norm's Inserts (beefier and better yet) and Jake's studs (the Ultimate). All 3 systems are within ~$200 in cost of basic materials.

Do some Scotch and water searching in here and in Deville to get a better picture of what you're up against.

(BTW, the car is worth saving - if not this current one, then a 2000 - 2004 model.)

talamant, The test analyzes the gasses present in the airspace over the coolant - the engine can be on or off - if combustion gas is present, it won't go away. When all else fails, read the instructions.

i got one and it didnt have instructions so i turned the car on with the tube in the coolant tank and after about 5 mins the coolant came out. so i did the test wrong. so all i would have to do it run the car put the tube in the coolant tank and suck the air into the block test tube? how long would it take to change color to yellow would it be instant or take a few sec.

Submariner409
05-31-09, 06:12 PM
The test is NOT for the coolant. It is for the airspace over the coolant. The cylinder pressure differential bubbles gasses up through the chemical fluid which changes color depending on the concentration of hydrocarbons in the air/gas bubbling up through the test fluid. You should not mix coolant with the test fluid. Give it 30 seconds to a minute...........

Talamant3z
05-31-09, 06:18 PM
The test is NOT for the coolant. It is for the airspace over the coolant. The cylinder pressure differential bubbles gasses up through the chemical fluid which changes color depending on the concentration of hydrocarbons in the air/gas bubbling up through the test fluid. You should not mix coolant with the test fluid. Give it 30 seconds to a minute...........

oh ok see coolant got into my tube. scared the sh!t out of me so just pull the cap off the coolant tank and suck the air into the block test tube. the color of the liquid was clear so if nothing is wrong than the liquid will stay clear?

Submariner409
05-31-09, 06:25 PM
Yes. You test the gas, not the coolant. No hydrocarbons, no color change.

Jays03dsg, You reading all this..........sort of germane to your original question...........

Jays03dsg
05-31-09, 08:10 PM
Yes Sub,

Im readng all this and my stomach Is turning. ive owned the car since new, always carred and loved it and am attached to it but I am sitting her stranded 500 mles from home and am at the mercy of the dealler. I am convinced it is a blown hg and wonder what will be next. Should I go ahead and dump it, take what they give me and rent a car to get home. IM SICK!!!

Any objective advice?

Submariner409
05-31-09, 08:32 PM
Like most others in CF I'm a hidden typist on the Internet. I can blow smoke or tell lies.........but that's not my M.O. My personal opinion ??? Given MY car in the same situation, I am attached to the vehicle and gain enough satisfaction and pleasure from it that I could see my way to repairing/having the repair done, either on the spot or later - driving conditions permitting. For me, my satisfaction with the vehicle is the determinant - for others, it's a cost-vs.-utility basis. This one is in your ball park. Keep it or trade it - either way you're out a lot of bucks.

AJxtcman
05-31-09, 08:44 PM
Yes. You test the gas, not the coolant. No hydrocarbons, no color change.

Jays03dsg, You reading all this..........sort of germane to your original question...........

it is CO sub not HC's

Yes the bad stuf that kills people. :bonkers:

AJxtcman
05-31-09, 08:51 PM
Please. It would be helpul here your thoughts. Do you think it is a bad thermostat? The vehicle has 105k mles newer water pump and belt and new coolant reservoir.

Just so I and everyone else here understands
How did you get the air out of the cooling system when the components were changed?
Also the Thermostat should be pointing down. This is a reverse flow cooling system.

Just think you get an air pocket in the cooing system and warm the engine slightly above the norm. This is on a year that the engine that is pron to HG failure.

I use vacuum and Air-Lift the Air out. This means I don't even need to start the engine before handing the keys to the customer 100% of the time.