Blown head gasket scenarios/ diagnosis

[Petros]

a compromised head gasket my not show up if you do a compression test. often it loses coolant so slowly it is difficult to tell if you are loosing it or not.

best way to tell I have found is to remove the spark plugs and with a strong flash light, inspect the piston tops (rotate the engine so each one in turn is at TDC). Coolant leaking into the cylinder, usually #1 or #2, will "steam clean" the top of the piston. Number 1 or 2 piston top will be clean, or almost clean, aluminum. Compare all 4 piston tops, you can tell the difference.

If it is running okay, you can delay action and just keep driving it, and checking the coolant level. Eventually it will become bad enough it is obvious the head gasket is compromised. Be aware however, sometimes it will just blow out all at once. so do not wait too long to correct the head gasket.

[xirdneh]

I use screw in compression tester that has two sets of threads on end for both thread sizes. Each size thread has an “o” ring. Been using it for 20 years and never had a problem unscrewing it. I prefer it cause I work alone and do not need to find someone to turn the key while holding it in place. I just finished a headgasket replace that only had low compression in one cylinder. So one clean sparkplug too. Another way to check for water is to remove all plugs and watch what happens when engine is cranked. If leak is real bad water will fly out of a plug hole.
Once I had a suspected headgasket that was hard to diagnose. I used the hose only from compression checker by unscrewing the tiny valve on the end. That was so I could blow air into cylinder , one at a time (piston has to be up and valves closed) . I removed radiator cap and topped off with water then watched water level when cylinder was pressurized. A leaking head gasket at cylinder will push water out of radiator

[dlb]

I use screw in compression tester that has two sets of threads on end for both thread sizes. Each size thread has an “o” ring. Been using it for 20 years and never had a problem unscrewing it. I prefer it cause I work alone and do not need to find someone to turn the key while holding it in place.

+1

I just finished a headgasket replace that only had low compression in one cylinder. So one clean sparkplug too. Another way to check for water is to remove all plugs and watch what happens when engine is cranked. If leak is real bad water will fly out of a plug hole.

+1

Once I had a suspected headgasket that was hard to diagnose. I used the hose only from compression checker by unscrewing the tiny valve on the end. That was so I could blow air into cylinder , one at a time (piston has to be up and valves closed) . I removed radiator cap and topped off with water then watched water level when cylinder was pressurized. A leaking head gasket at cylinder will push water out of radiator

I've never thought of or heard of this before. I like it a lot, gonna keep it in mind.

[Esaus]

I suspected my car initially had a blown headgasket. The coolant was heavily colored brown. Turns out either someone put just water in the coolant system or the coolant was extremely old. I replaced the radiator which had corroded heavily. I flushed the system several times and even filled it with vinegar. I managed to get it somewhat clean but its still heavily dirty. Ive since then driven maybe 7000km with the car. Compression is 175psi on all cylinders, it doesnt use oil or have contaminants in there or use any coolant. Havent managed to get the rust color out from the coolant. Ill keep changing it and flushing it from time to time.

[dlb]

I flushed the system several times and even filled it with vinegar. I managed to get it somewhat clean but its still heavily dirty. Ive since then driven maybe 7000km with the car. Compression is 175psi on all cylinders, it doesnt use oil or have contaminants in there or use any coolant. Havent managed to get the rust color out from the coolant. Ill keep changing it and flushing it from time to time.

I've used tools like this for that kind of problem:

https://www.amazon.com/acdelco-91002-2- ... ncestog-20

here's a pic in case the link dies:

610iXB2NQKL._AC_SL1500_.jpg

I have one like that I bought years ago, I actually used it just last night. You hook it up to a garden hose and an air compressor. When you squeeze the trigger, it blasts pulses of water out. It should have a rubber end that you hold firmly against the opening of the radiator, block, or heater core. Have the other end open and blast away until the water comes out clear. Do it again the opposite direction. I repeat that a few times. It cleans out scale and buildup. Works amazing.

[Esaus]

I flushed the system several times and even filled it with vinegar. I managed to get it somewhat clean but its still heavily dirty. Ive since then driven maybe 7000km with the car. Compression is 175psi on all cylinders, it doesnt use oil or have contaminants in there or use any coolant. Havent managed to get the rust color out from the coolant. Ill keep changing it and flushing it from time to time.

I've used tools like this for that kind of problem:

https://www.amazon.com/acdelco-91002-2- ... ncestog-20

here's a pic in case the link dies:


610iXB2NQKL._AC_SL1500_.jpg


I have one like that I bought years ago, I actually used it just last night. You hook it up to a garden hose and an air compressor. When you squeeze the trigger, it blasts pulses of water out. It should have a rubber end that you hold firmly against the opening of the radiator, block, or heater core. Have the other end open and blast away until the water comes out clear. Do it again the opposite direction. I repeat that a few times. It cleans out scale and buildup. Works amazing.

Looks cool! I will check it out. I replaced the coolant last week when I had the engine out to replace a bunch of gaskets and the clutch so I dont want to replace it again now but I will check it out later.