blown gasket -- how much is the car worth?

[dstarr]

Be sure it is a head gasket problem. Just over heating could be a lot of different things, most of them a LOT cheaper than head gaskets.
Do a compression check. Get a compression gage at an auto parts store. Get a spark plug socket, and wrench. Get a friend to help.
Remove all the spark plugs. Mark the number of the cylinder onto each plug as you remove it. Keep the crud in the plug hole from going into the cylinder when the plug comes out. Blow out the plug area with compressed air, or use a vacuum cleaner or one of those "dust it" cans of air they sell for cleaning out computer keyboards before using the wrench.
Jam the rubber business end of the gage hard down into a spark plug hole.
Have friend crank the engine.
Watch the gage pump up. Note pressure obtained on a piece of paper.
Do all eight cylinders the same way.
Look at the pressure readings on the paper. if they are all about the same, the head gasket is good. If one or more are way low, you have a leaky head gasket. Each head gasket (there is one on each cylinder bank) seals four cylinders. When they fail, they fail one cylinder at a time rather than all at once. The failed (leaky) cylinder[s] will read lower than average.
How low is too low? I'd call anything less than 10% cylinder-to-cylinder variation good. 50% is definitely bad. For readings inbetween 10% and 50% get the opinion of a real mechanic, rather than a shade tree type like yours truly.
Read the plugs while you have them out. A light tan coating on the electrodes and ceramic insulation is good. Wet plugs (oil or coolant) are a bad sign. Heavy black carbon buildup indicates an oil leak. If the electrodes are burned round and the gap is burned out wider than spec, treat the engine to a set of new plugs. A wet plug from a cylinder with low compression is confirmation of a leak. A good looking dry plug from a low compression cylinder would make me repeat the compression test just in case I got mixed up. A net search or a library trip will yield a book with color pictures and instructions on reading plugs.
If you replace the old plugs, put them back in the cylinders they came out of just in case you want to read them again later. If you put in new plugs check the gap with a wire gage. New plugs usually come from the factory gapped right, but it is always worth a check. Put a drop of the right anti seize stuff on the plug threads before replacing them. Don't strip the threads in the plug hole when replacing the plugs. Start the threads by hand and hand tighten them. If the plug won't start or screw down by hand, you have crud in the threads or they are cross threaded. Once started, tighten with the spark plug socket and wrench. If you have a torque wrench and know the right torque go that way. If you lack one or the other, tighten the plugs enough to squeeze the metal sparkplug gasket flat but not so hard as to strip out the threads.

[Skullman]

Originally Posted by cockmanje

~Snip~ Does anyone know any good mechanics in Western NC? I kind of hate to take it to the dealer...

~ Here's a couple Engine Dealers; Power Pro Driveline and WADE'S AUTO PARTS eBay Store. Good Luck!

Skullman {:{}

[cockmanje]

Here's the Wednesday morning update: The head gasket price my mechanic quoted me did not include the timeserts. The price with the inserts is $3300. He gave me the warning that sometimes when the engine has been overheated, it can get soft and the threads still may pull, and he can not be responsible for this. He can put a used engine with comperable miles (66k) for $4000, including a 6 month parts warranty. Labor warranty is extra. The price is more for a rebuilt engine, and a new one runs about $9000.

What do you think about these prices?

Thanks, jupiter57, for the list of alternatives to head problems. I did not do a cylinder test, but I did check the other things. I am sure the mechanic would do this as part of the diagnostic before he pulls the engine out, but I will ask to make sure.

[Kev]

I think if the used engine has not been timeserted you will be in this same postion again in the near future.

Get some other opinions from trustworthy mechanics.

[bkenneyb1]

I HAVE A 97 DEVILLE 130K RECENTLY STARTED SMELLING BURNING OIL THEN CLLANT LEVEL LOW ALRMS. CHANGED OIL AND ADDED DEX-COOL AND ENGINE STILL RUNS HOT.dOES THIS SOUND LIKE BLOWN HEAD GASKETS?

[cockmanje]

I don't know. A cylinder test was the proof for me.

[92Deville]

Originally Posted by jupiter57

At 66K, I'm willing to bet it Does Not have a blown Head Gasket.
Be very wary of ALL Dealers, and most independent shops, seems everyone thinks that if you can afford a Caddy, you can afford to sink big bucks on it.
Diagnosing ANY Cadillac cooling system issue as a "Blown Head Gasket" seems to be a disturbing trend among most mechanics.
I would start with the basics: ensure you have the sealant tabs/powder in the Dex-Cool, check the water pump belt tensioner for proper operation and tension, the water pump belt (the belts WILL stretch with age, causing it to slip, especially at higher speeds), the purge tank cap, make sure the purge line is clear, carefully check all your hoses, even a pinhole or loose clamp will hurt your cooling.
Check your cooling fans for proper operation.
Your radiator could possibly be clogged, check it for sufficient flow and back flush it if it does not flow freely, or even have it proffesionally cleaned by your local radiator shop.
You say you have exhaust in the coolant, this wouldn't by chance have been discovered by the infamous "Hydrocarbon" test would it? The hydrocarbon test is pure bunk! Heated coolant, by nature, produces hydrocarbons. The only true test for a blown head gasket (barring oil in coolant or vice-versa or steam steadily produced from the exhaust) is the cylinder pressure test. A search of this site will tell you how.
I speak from experience, having purchased 3 DeVilles this year alone, all with "blown head gaskets, all cheap, and only 1 of the 3 truly had a bad head gasket. ($1300 for a used engine and voila, a nice gift for my daughter), one (97) had a clogged radiator on a recent new crate engine, causing it to overheat at extended highway driving, the other (98) simply needed a new pressure cap as the coolant was overflowing at 230 degrees, causing a loss of coolant which resulted in overheating.
Hope you take the proper steps to check these things before you let someone take all your money, possibly needlessly.
I firmly believe that a large majority of Northstar cooling issues can be solved quite inexpensively, and that their reputation for "Blown Head Gaskets" is almost entirely due to rip-off artists and/ or ignorance.
Hope this helps before you shell out big bucks needlessly.

If heated coolant produces hydrocarbons like you say then how could the hydrocarbon test be pure bunk? Coolant in the cylinder(s) would be being heated/burned and then would show high hydrocarbons out the tail pipe.

[92Deville]

Nevermind. I'm just a little slow I figured out what you are talking about with the hydrocarbon test.

[The Ape Man]

After sniffing many different engines with exhaust analyzers all I can say is that it is has been 100% correct every time. This even includes times when the exhaust only showed 8-10 ppm more than shop air. I know because I ripped the engines down every time one got repaired and not junked. Dunno why heated coolant would produce hydrocarbons. How hot does the coolant have to get to produce hydrocarbons? The sniff test can be done on an engine that has just been started so the coolant can be none too hot.
Another thing that makes me believe coolant does not emit hydrocarbons is that emissions certification requires testing the entire vehicle not just the exhaust. I heard (so I'm not 100% sure but it makes sense) several manufacturers actually had to change engine paint because of this. Ford Blue was supposed to be one engine paint that got dumped.
I fully agree on your assessment of thieving mechanics. There are plenty of lowlifes in the trade. The only business with more snakes is the high end audio business. Just remember that if a machinist says something then it must be gospel.

[cockmanje]

I just got the car back with the used engine in it, but there is a markable noise difference between this engine and the previous one. This engine has a noisy growl when accelerating through the first two gears. It is loudest when the engine is cold. If I accelerate very slowly, I can avoid the growl. Is this normal, or is there something wrong?

EDIT: I started a new thread about this:
http://www.cadillacforums.com/forums...031#post466031

[powerglide]

How much did you end up payin?

Prices sound in line with what I have read.

the wierd noise doesn't sound normal IMO.

[jkk]

Originally Posted by cockmanje

EDIT: I started a new thread about this:
http://www.cadillacforums.com/forums...031#post466031

This link is bad. It should be http://www.cadillacforums.com/forums...ad.php?t=55774 (Loud growl on acceleration)

[8YrCaddy-Tech]

To answer in short....if the head gaskets are blown you are prbably looking at an engine. Almost everytime it pulls the threads out of the block, sure there are time-serts...waste of time....i did time serts on 8 cars 7 come back within the next 3 moths follwoing repairs with the inserts pulled fromt he block...makes sense....just drilling into already weak metal. You can try but i feel it is a waste of time...i ahve owned several cadillacs i have gotten cheap bb/c of blown head gaskets...i as a cadillac tech won't even repair them for myself i got used engines to throw in them and be done with it...9 times out of 10 you can find a decent used motor....also if you do....try to find an engine out of a 98-99 seville they will with with a y or 9 vin...i have done it with no problems....only thing different is the y engine has different cams...for a little extra hp....would not be noticeable

[cl1986]

Originally Posted by 8YrCaddy-Tech

To answer in short....if the head gaskets are blown you are prbably looking at an engine. Almost everytime it pulls the threads out of the block, sure there are time-serts...waste of time....i did time serts on 8 cars 7 come back within the next 3 moths follwoing repairs with the inserts pulled fromt he block...makes sense....just drilling into already weak metal. You can try but i feel it is a waste of time...i ahve owned several cadillacs i have gotten cheap bb/c of blown head gaskets...i as a cadillac tech won't even repair them for myself i got used engines to throw in them and be done with it...9 times out of 10 you can find a decent used motor....also if you do....try to find an engine out of a 98-99 seville they will with with a y or 9 vin...i have done it with no problems....only thing different is the y engine has different cams...for a little extra hp....would not be noticeable

WHAT?????

Many people on the forums have done headgaskets themselves and not being master mechanics and they did just fine with no problems afterwards. This is just plain wrong, your scaring all these people for no reason. If you got 7 out of 8 returned to you, you obviously did something wrong. The timeserts dont weaken anything, infact they are stronger than stock if done right.

[cockmanje]

Bad News... The rattle has increased, I think it is the exhaust line rattling. I have an appointment Thursday to get it fixed, free of charge, by the service department that installed the engine. However, my wife calls today (Monday) to tell me the Check Coolant Level indicator has come on. This is a newly installed engine! Why would the coolant level be low? Could the heads be bad like the previous engine? Would the mechanics not have checked for something like this before they installed the engine? The engine is guaranteed for six months, but the $2300 for labor is not guaranteed!

Question: My brother-in-law says that even though the dealership claims not to guarantee their labor, by law they have to if they are the ones that supply the engine. Is that true? Remember, I still don't KNOW that the engine is bad.