My ls 400 has 250k miles heat guage goes up , fluid comes out overflow. I took the t-stat out installed a washer. Changed the water pump; I can see bubbles in the plastic tank. Used head gasket sealer but still heats up. No water in the oil. Does this sound like a head gasket? The electric fans don't come on unless the ac is on. My plan today is to disconnect the sensor wire which keeps the fans on 100% and try again. Whats the flat rate on the head gasket.

 

heh... without looking, I think head gasket job is like 16-20 hours for both heads...

thats $2000 easy...

you'd be better off sourcing a motor...


and it does sound like head gasket to me... could also be a very plugged up radiator too though...

 

i havent heard of a 1LS having a BHG.

 

You need to check for debris between condenser and radiator. You have to remove the plastic cover to get access to the radiator mounting bracket, remove the two 12 mm and push the radiator toward the engine. You may be surprise how much craps collected in there and prevent the good air flow.
Then check the operation of the fan clutch and blockage in the cooling system

 

With that kind of mileage. I think it's time for a new radiator seriously. The fan should kick on correctly. Make sure you don't have a bad fan relay. GL.