OK so my LS VTEC is losing coolant. About a liter per week being used every day.

I don't see milky oil. I don't see oil in water either.
I don't see white smoke coming out of the exhaust.
I don't see any water leaks and I have checked many, many times.

Compression test turned out great (which is what really confuses me)

235 232 235 232 (psi)

The engine has power and runs fine, won't overheat (unless, of course, if it runs out of coolant, but that is obvious), has a smooth iddle and no obvious problem.

I don't have an easy and quick way to perform a leakdown test at home.

With all that info (specially the compression test) is it still possible that my headgasket is blown???

Thanks in advance

 

Wow - that's a lot. If you were losing that much through a bad head gasket, you'd have some serious issues (or at least see it in the oil and exhaust steam), so I'm not leaning in that direction.

Do you smell coolant in the engine bay or interior when the car's running? I'd keep an eye out for leaks both after the car's been sitting, and after it's been run for a while. Aside from the obvious places (radiator, hoses, water pump), I'd look under the dash at the heater core, or maybe even the freeze plugs in the block.

 

Well I actually cut the heater hoses long time ago, the car only runs like 3 water hoses, from head to radiator, from radiator to thermostat housing, and an U-like water hose to bypass the TB. The rest have been plugged. The radiator is a RS Machines aluminium radiator, radiator cap is fine, I guess.

Is a liter too much? Considering the car is used every day and since fuel in Venezuela is practically free (and the city I live in has a lot of mountains), I floor it all day long.

Could it be a leak so small that water evaporates just after leaking out of the system thus not letting me easily detect the leak?

Can't think of anything else, and of course I don't want to take the head off, 1st because I don't have time and 2nd because it was nicely built with a Cometic headgasket, and the GSR headbolts I used have been torqued like 3 times now.

 

Pressure test the cooling system.

 

I would pull the spark plugs and check their color.
If one looks especially clean it could be burning coolant.

 

Turns out I found a way to do a leakdown test and bubbles came out the radiator as soon as I pressurized cylinders.

So, CONCLUSION

A compression test DOES NOT say whether you have a blown headgasket or not.