Hi everybody,
I've been experiencing some strange temp behavior with my bus.
During the initial warm up the temperature gauge goes up to about 3/4 of the gauge and hangs around there for about 45min to an hour, afterwards it drops to about 1/2 (around the LED, which I consider to be the normal temperature) and stays there for the rest of the drive no matter how long I drive.
This only happens when the engine is completely cold (for example when it's already "dropped" to about 1/2 and I stop for 30min-1h for whatever reason, when I start again it's still hangs around 1/2, but if it sits overnight it starts again at 3/4 and goes back to 1/2 after the time I've said)
Last month I installed a new Behr thermostat (unfortunately made in China) in the bus. Before the temperature always stayed at about 3/4 of the whole time.
I also noticed residual pressure in the expansion tank, even when the engine is completely cold. Is that normal? No coolant loss or strange levels in the refill tank behind the flap. I had the idea that there should be no pressure in the expansion tank when the engine is cold. (unless the cylinder head gasket is on its way out, but I doubt that, since the engine is almost "new" and the bus has never overheated since the overhaul)
The engine has done about 8000 miles since a complete overhaul.
The cylinder head was checked. It had no cracks at all.
The cylinderbores had deep scratches and even the biggest OS was not enough to remove them, so liners (std 76mm) were installed in the block (all 4 cylinders).
Any ideas? Should I be worried or am I just paranoid?
Over on the German forums i'm told that the likely culprit is the cooling loop is not properly bled for air.
Any ideas?
Cheers and thanks
Is there a small coolant line going to the reservoir?
Can you see if there is coolant flowing through it?
Any air in this line?
How's your fuel gauge?,..
I think it runs off the same voltage regulator.
Update.
Bled the system again on the radiator a bit more toughly and my Temps are fully in the normal now
