ben951

...or it is for me at least.

I am suspecting a head gasket failure on my car, but i cant be sure, and i guess some of it may be paranoia, but here are the symtoms.

About a month ago i started to smell a faint coolant smell inside the car, coming in through the vents, only when the a/c was on, i smelled it a couple of times and i havent smelled it since, although i havent had the a/c on since either, the coolant smell only appeared just as i was parking up after boost runs, but not real hard boost runs.

After smelling the coolant i checked the plugs, they were real black, from a super rich running problem, but thats another issue (i think) all of them were the same, and at that time i marked the coolant level too. It doesnt seem to have dropped alot, but it may have dropped a little, at that time i routed the coolant overflow hose into a bottle, and to this day there hasnt been any coolant in there.

Then, yesterday when i was drving back from the beach with my brother following he said he saw white smoke when i took my foot off the throttle after being hard on it, like to shift or something, he said it was definitely white smoke, and it was definitely noticeable, now i was hard on the gas the whole way home (60 miles) probably the hardest i have driven the car in a while, would the puffs of smoke be a coincidence? when i got home i checked the plugs again, still black and sooty, and i also looked in the cylinders, no coolant in there, so my question is, am i being paranoid, or should i start preparing for a headgasket replacement?

Thanks in advance

Ben

Ski

How many miles on the car, any mods, what boost level?

If it was blown, you'd be smoking the road behind you like you were fogging bugs. If might be seeping a bit and getting sucked in when you go hard on the vaccum. If you have an MBC, you might try turning it down but if you've got WHITE smoke and the coolant is dropping and you don't see coolant anywhere else, then it's probably not far off, my guess.

You don't want it to blow while hard on the boost because that can loosen carbon from the steam, wash oil off the cylinder walls, scratch walls, and it can get worse from there, like what happens when you forget that the race engine you built, the car still has cheap gas in it from CO.

ben951

wow, thanks, i dont drive it that hard too often, so hopefully it will hold on. it is an 86 with around 87,000 miles, no mods apart from cat bypass and BOV, and i am running stock boost levels. If it is starting to seep, how long do you think i have before i will have to change it?

Oddjob

Coolant smell through the HVAC system could also be a heater core leak.

Smoke out the tail pipe after letting off or shifting can also be oil/combustion smoke from worn compression and/or oil scraper rings - but the smoke will not be pure white, more of a gray puff; but not black or dark. If it is pure white, that is coolant and would be an indicator of a head gasket problem.

Other symptoms would be the milkshake crap on the oil fill cap after long drives (short drives do not heat the oil up enough to burn the moisture out, so you can get a lot of goo on the oil fill cap when taking short trips, especially in cooler weather - normal). After driving the car hard (on boost), a head gasket leak can/will over pressurize the coolant system, so it may belch out coolant past the overflow tank cap.

Ski

Make sure the smoke is white...and not blue. Cars going on vacuum, that puff some smoke could be a valve stem seal or even a scratched cylinder wall - not to try to scare you. If it is indeed white, if you don't want to change it now, I would stay off the boost while driving. Pressure test the cooling system and make sure you don't have any leaks. If the pressure goes down, pull the coil wire, turn the car over a couple of times and see which plug is wet. Once you confirm that, I would change it now. It's a "do it now and pay now or do it later and pay BIG later".

Trucho-951

I believe there is a dye test, you add the dye to your coolant it will react with exhaust gases and change color if combustion gases are getting into the cooling system.

Tony951

When I was losing coolant due to a head gasket (would only lose coolant after hi boost runs ~14psi), my local Porsche tech inserted an exhaust gas analyzer probe into the top of the coolant reservoir with the car running. The analyzer picked up about 25-35ppm of HC's - this confirmed my belief that the head gasket was starting to leak. In this manner you could find out immediately whether or not exhaust gases (esp under boost) are breaching the gasket.

ben951

thats cool, it would be nice to know for sure, i will ask my mechanic then because i have to take it in sometime in the next couple of weeks to get the timing belt re-tensioned. I will ask my brother if he was sure it was white, or if it could have been grey, by the sounds of it though i kinda hope that it was white!!

mutzman951

Hi there,

Smell the dipstick! Change the oil and look for coolant. Look in the reservior for oil. Or you can call me or stop by, or e-mail me. Bankers hours, please! I have a 15 month old son and a pregnant wife!

Oviedo, Florida is close to Orlando, in case you're reallly new here.

doug
407-929-6394
mutzma951@aol.com