Happihank

95000 miles been servced at Rydell - their best mechanic - passed pressure test , put on new valve cover still get message - topped off this am - not spotting can't see any hose leak
Any thoughts ?

thanks

schpenxel

There is no level sensor on these cars, something is wrong with the temps the ECM is seeing making it think there's a coolant level issue.

Why would he replace a valve cover for this?

What's the coolant temp showing up as?

Any codes?

Happihank

Coolant temp is normal - taking car in today it's definitely losing coolant very slowly
Thanks for your response

mrk1957

He did a pressure test? What was the leak down rate? I wouldn't think you'd pass a pressure test if you're leaking fluid that fast.

4SUMERZ

By passing the leak test, what was the starting pressure and end pressure over what period of time.

The reason I ask, I had a similar experience, losing some coolant, no drips etc. Pressure test did not show anything substantial. A few months later, I noticed a bit coolant on the belt pulleys, but no sign of anything leaking. I tightened and checked every hose clamp, and some were a bit loose, but none leaking.
I did another pressure test, left it on for 24 hrs, noticed a definite drop in pressure, and finally, a small stream of coolant coming from the pump pulley. I changed out the pump...no further issues.

I figure that if the pump pulley stopped in a certain position, it may not of leaked by the seal. If it stopped at a point where it leaked past the seal, the coolant would drip on the hot pulley or engine and either gel up, or evaporate.
Here is what the back of the pulley looked like after I replaced the pump with a new one. Notice the caked on coolant on the inside of the pulley. The problem is that it'a almost impossible to see back there with the water pump installed. maybe a mirror.

Dano523

My guess, one of a few things things,

if you are loosing fluid, then water pump shaft seal mostly likely if there is no signs of DEX-COOL in the motor oil from a blown head gasket.

If you are not loosing fluid, could be either a faulty T stat or temp sensor, ,the impeller on the WP broke free of the shaft/is not spinning the same as the shaft, or the Fan is not coming on instead (burnt connector).

Hell, if the DEX-COOL was just changed, then could be air still in the system that is causing the fault code.

Happihank

Its in the shop right now, and because the coolant temp is controlled by an algorithm its a step by step process they tell me. We shall see. Thanks for your input guys.

H

schpenxel

Coolant temp is pretty simple, just a regular ol thermostat and PWM fan that ramps up when coolant temp gets higher

The decision on whether coolant temp is behaving on the other hand is a bit more complicated

Happihank

Its now going back to the shop for the third time next week. A small leak was discovered but that didn't stop the slow leak problem. So far it hasn't been much $- we shall see what happens next. Very frustrating.