triage400

1994 ls 400 215,000 miles with all services belts pulleys water pumps etc.at 205,000 miles.. has had on going coolant level drops fairly quickly from coolant plastic fill bottle..No water out exhaust pipes..no water in oil..no water in transmission fluid..no water leaking out heater core or the heater valve.no water under car...WHATS UP..head gasket?.The past history of the car has had at least 5 major overheats from bad pump bad radiator..it runs perfect.. .Ive pressure tested coolant system it held 15 psi for like 15 minutes....car runs idles etc perfect...this thing just keeps on running with ice cold a/c in arizona..some say these head gaskets rarely never go out..maybe?

YODAONE

Check your water control valve on firewall

oldskewel

iTrader: (1)

If you have doubts about a head gasket, this simple tool will give you a pretty definitive answer on that:

A few years ago I had some very slow leaks on the radiator on my '91, where it seemed to need heat as well as pressure to make it leak, so the initial pressure tests did not reveal the leaking. You could try removing the intake thing above the radiator so you always have a good view of it (leave it off the car until you get the leak source isolated - it is not needed). Clean everything around there carefully with a garden hose spray. Then every time you finish a drive, pop the hood and look around for wetness or dried coolant residue (little white droplet marks).

dicer

Put florescent dye in the coolant and look for the glow. They sell kits at autoparts stores with dye, black light and glasses to do that.

Michael88

Any white somewhat powdery looking film around the coolant resevoir cap? This might sound strange but have you checked the tranny fluid level? Any belt squeals at start up could direct you to a hose under the intake and over the belts. Dripping on belts and flying around.

triage400

Found the water leak...way up on back side of engine. I cant see yet where exactly....The heat control valve looks good..Thanks for all the insights...