Need opinions on coolant disappearing.

[Liquidity]

Well I mean with the tests I've had done, It would appear as though there's no external leakage... so where else could it go really? If you pump the system with pressure and it holds overnight, it can't be leaking anywhere, right?

What is the head gasket's main function?

[15Michaeljoseph]

Are you doing coolant leak tests with the engine hot? Some leaks open up more when the engine is hot, such as cracks in the block or head. When I worked at Land Rover, we had a particularly hard to diagnose leak due to a crack in the block, INTO A CYLINDER. It only leaked when the block was hot, and another tech finally found it when he ran the engine till it was hot, hooked up the pressure sensor, and stuck a scope into the cylinders to look for evidence of a leaky head gasket, only to see a fine spray halfway down the cylinder.

tests have happened with the engine cold/ cooling down. I see how this could be an issue because when things get hot they expand... so
in theory, there could be a crack in my head, block, or a headgasket issue allowing coolant to dip into a cylinder..... but wouldn't that cause some smoke? especially in the morning? I've got nothing like that, see, unless it's winter. and what about my lack hydrocarbons? I mean that all makes sense, so am I just being dumb?

What is the head gasket's main function?

to provide a sealing surface between the head and block, provide a good seal for compression, and so that the coolant stays where it belongs, and the oil stays where it belongs too.

...right?


I feel like maybe I should get a couple opinions from shops in the area before I go pulling the head, maybe have my exhaust tested again.

Thanks for all the effort so far guys


--Mike

[Liquidity]

to provide a sealing surface between the head and block, provide a good seal for compression

And what happens when the seal leaks between the cylinder and the water passages?

[Andy.B]

And what happens when the seal leaks between the cylinder and the water passages?

Then he would have hydrocarbons in the coolant, which op stated several times he had tested for, and is not the case.

Don't be an ass. Op has clearly taken the correct steps in diagnosing this so far.

[15Michaeljoseph]

Thanks guys. The car has been tested for hydrocarbons, everything was normal.

was doing more research, and thought it might be helpful to mention that the car is manual, so no cooler lines from radiator to transmission or any of that stuff.


--Mike

[Dirty325ix]

The oil is a little lighter brown with tiny amounts of whitish snot on the filler cap and dipstick
--Mike

Wait doesn't that sound like a small amount of coolant in your oil...with the snot color and all

[Dirty325ix]

You do a leak down or compression test