Blown Head Gasket??

BlackMark8

Registered
Im not sure about it but its not looking good...

Car keeps overheating, the water is pouring out of the cap. It had a new radiator, new water pump and thermostat removed. Ran fine for long time then started to overheat. Water coming out the sides of the cap... again. So , i figured what the hell maybe the cap is no good... got a new one.. and wala, worked fine again for several more days.... then it started again, i got real sick of pulling over every 10 miles to cool off and add water. it only had water...

i said screw it... modified the cap so it would never leak again and bang ! radiator blew apart the plastic on passenger side.

The last two times it overheated (when i say overheated i mean its passed the "M" on the "NORMAL" section of the gauge.)

THE HIGHEST IT EVER GOT WAS THE TOP OF THE "R".
The car never actually red-lined... but

I noticed a terrible sound and the oil light came on.... sounded like the engine was running backwards (like old cars do sometimes when you shut them off)


Now im in the process of installing new radiator (brand new) and t-stat. Do you think that not having a t-stat could make it put more pressure on that res. box and make it keep popping the caps ?

Your info is greatly apreciated.
 
That 'terrible sound' would be a rod knock. When old (or sometimes not so old) cars do that it is called 'dieseling' - it is when their is an excess of fuel in the combustion chamber, and the car is running without spark - just like a diesel!

So, if you had a rod knock in combination with an oil light (low oil pressure) - I would be finding a new motor, not radiator.
 
yes but cars can overheat and make that sound, i dont think its a rod knock, because on cold startup its fine. and continues to be fine forever as long as you can keep coolant in it.
 
Is there coolant in your oil?

Is there oil in your coolant?

Do you see white smoke in the exhaust when you start it?

Have you looked at the sparkplugs and comapred what they look like cylinder to cylinder?

Of course, do you fill your coolant at the crossover pipe?
 
One of the signs of a blown head gasket is the cooling system boiling over even when it isn't hot. I have seen one that "boiled over" when the coolant was barely warm to the touch. What happens is cylinder pressure is being directly leaked into your coolant system, radically overpressurizing it.

I'd check your oil and see if it is "chocolate milk" looking. Also, if you have mysteriously missing coolant, that's where it is going: into your cylinders.
 
A good garage will be able to chemically detect exhaust in the coolant if that would be the case. Usually if it's extreme, you can smell coolant in the exhaust.
 
i said screw it... modified the cap so it would never leak again and bang ! radiator blew apart the plastic on passenger side.

Ok, who gave you this idea!?! Lol! :eek:

Like everyone has touched on, you could have several different issues going on but a tell tale sign of a bad headgasket is either coolant in the oil or exhaust gases in the coolant.
 
One of the signs of a blown head gasket is the cooling system boiling over even when it isn't hot. I have seen one that "boiled over" when the coolant was barely warm to the touch. What happens is cylinder pressure is being directly leaked into your coolant system, radically overpressurizing it.

I'd check your oil and see if it is "chocolate milk" looking. Also, if you have mysteriously missing coolant, that's where it is going: into your cylinders.

I have exactly the same issue you have. I've been dealing with it for about two months. I replaced the tstat and the radiator, but the fluid keeps leaking away and my mechanic tells me that the head gasket is blown between a water passage and a cylinder. I have no oil in the coolant, or coolant in my oil. He ran a chemical test on the coolant and it definitely has hydrocarbons in it.

It is sometimes (but not always) hard to start. I attribute this to the fact that after it gets shut off, depending on the temp, it sometimes leaks coolant directly into the cyylinder. Actually, it starts, then cuts off immediately. It does this a couple of times, then runs badly for a few seconds, then runs fairly well. I guess it takes a few seconds to flush the water out through the valves. Since water doesn't compress, this is probably not a good thing.

If anyone out there wants to make a few bucks, I'm looking for someone to fix it. I've found a 70K '96 Mark VIII engine for what sounds like a good price, and I may either swap in another engine, or, if cheaper, just change the gaskets.

If you're interested, you can send me an email at markviii@dslextreme.com

Cheers
 
I have exactly the same issue you have. I've been dealing with it for about two months. I replaced the tstat and the radiator, but the fluid keeps leaking away and my mechanic tells me that the head gasket is blown between a water passage and a cylinder. I have no oil in the coolant, or coolant in my oil. He ran a chemical test on the coolant and it definitely has hydrocarbons in it.

It is sometimes (but not always) hard to start. I attribute this to the fact that after it gets shut off, depending on the temp, it sometimes leaks coolant directly into the cyylinder. Actually, it starts, then cuts off immediately. It does this a couple of times, then runs badly for a few seconds, then runs fairly well. I guess it takes a few seconds to flush the water out through the valves. Since water doesn't compress, this is probably not a good thing.

If anyone out there wants to make a few bucks, I'm looking for someone to fix it. I've found a 70K '96 Mark VIII engine for what sounds like a good price, and I may either swap in another engine, or, if cheaper, just change the gaskets.

If you're interested, you can send me an email at markviii@dslextreme.com

Cheers

Best of luck with that, and your mechanic is correct: you are burning up your coolant in your cylinders.

I don't actually have this problem with my Mark and hopefully never will, but I did see nearly that exact scenario with a 98 Bonneville I owned for a time.
 
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