ahacme

Just got the radiator and thermostat replaced. No coolant visible on the surface or the pavement but it disappears almost 1/4 from the reservoir every day. I visually inspected all hoses but no leak is visible. Any insight on where the coolant might be going? Anything I can do to diagnose the problem?

ES 300, 1996

Lexmex

I am taking it you replaced your coolant, too, when you had the other things replaced. This happened to me with my RX300, and I had to fill it up to the full line each day for 3 days, and then it was back to normal. Otherwise, the only other place it can be going is via a leak, and I would check all around for a wet spot immediately after driving it...don't wait for puddles or the next day.

Pheonix

Ditto. Otherwise, warm the engine & check the compression.

ahacme

Thanks, I'll fill up the coolant again upto the max line and see if it stays that way. Another question, how can I check the compression?

Pheonix

Run the engine until it comes completely up to temp, take the plugs out & screw in a compression gauge. Watch the gauge while you turn the engine over (take out the EFI fuse so it wont squirt fuel at you)


Or hook in a more expencive leak-down gauge & do the same thing.

or take it someplace nice & have a pressure test of the cooling system done.

amf1932

Before you go to the bother of doing a compression test, do a pressure test of the cooling system. There's always the chance of a leaking head gasket which allows a bit of coolant to be drawn into the combustion chamber.
Sometimes you can see white vapor coming out of your exhaust pipe, but if the leak is very small you probably won't see it.

1993ES300x

as for the blown Head gasket.... i had this happen to my ES300(now sold)... make sure no white smokes are coming out the tail pipe or your engine oil looking muddy... good luck and pray it's not a blown head gasket......