Let me know if i shouldn't start a new thread,

My Corolla 2003 coolant level drops slowly when not driving. Already had mechanic checked, they put some sort of pressure pump thing to test, but no leaks observed. changed the radiator cap but still dropping.

The behavior is very weird, when driving everyday, it doesn't drop at all, even driving from jb to kl it doesnt drop anything. But when I park my car there for 2 or more days, it starts to drop. Sometimes my friend fetch me during weekend(Sat & sun) for like 3 weeks (total 6 days over 3 weeks) then it drops below the 'LOW' level.

Some says it's engine consuming the coolant, but it doesn't explain driving from jb to kl doesn't drop any level. It's really annoying as it only drop sometimes when not driving.

Any sifus can help? Thanks.

I just bought original long life coolant and really keen to put it in asap but it's leaking now.

This post has been edited by NoobHacker: Mar 18 2019, 01:06 PM

You can try to check whether the hose got leaking, or connection between hoses and radiator/thermostat/water pump/etc got leaking. Worst, your radiator leak

Try another mechanic. Maybe the one that check for you didn't do a thorough checking. The fact that it leak when idle already means somewhere it is leaking. If few days only leak until low means the leakage is quite serious. Is there no watermark at all the bottom of the car where it is parked? If not then where does all the water gone to? Evaporate to thin air?

Actualy what is an acceptable coolant lost level? I topup every half year to a year, even then its not at low level yet, just not max level anymore.

When mechanic check the car with the pressure thing.. was the engine warm or cold ?

You say only leak after few days right ?.. means it's leaking only when cold.

You probably have a leakage when some part of the system shrink when cold.. hot it expands, then no leak lah...

hmm if its like what you said.. maybe try changing mechanic..?

TS,
Go get a 2nd opinion. That said, loosing coolant when an engine is not running/cold should leave signs on where its leaking, have you checked the radiator hoses and connections?

Or have you looked under your engine oil and radiator/spare tank cap and maybe even d ATF dip stick to see if there's any water residue, in case of leaking gaskets or a cracked radiator?

Water jacket cracked maybe.

Sound like a very slow leak which is very hard to detect by pressure test alone.

If you think the 'engine consuming the coolant', does the exhaust smell sweet?

put UV tracer into coolant and cheap,UV light from China

immediately see where leak is