Temp gauge playing silly buggers (not electrical)

[crazyhorse]

The journey continues...

After 2 weeks of driving, temp gauge has been behaving like it should. Sitting just under half way.

Last couple of days Ive noticed it doesnt sit where it has been. Now it just sits above the first white mark. (really really low). It does move a tiny bit but not enough. So its reading really cool.

Its not been as warm in the van either, warm air still coming from heating vents but it doesnt feel as warm (I know its really bloody cold outside). Incidentally, the van is running a bit rough... feels like its holding back.

Few questions.

1. Is it the thermostat?? Have orderd one just in case from Heritage
2. A have a late cooling system.. can I change this without bleeding??
3. I have a 500 mile round trip this weekend, Can I do this without changing the thermoststat if it doesnt arrive in time.

As always thanks

[Ant-t]

It sounds like your thermostat is stuffed, I recently changed mine after a long time reading very low, by the white box, far left. Straight after installing a new one, c/o brickwork, it reads just shy of 12 o'clock consistently.

[AngeloEvs]

Changing my thermostat I lose about half a litre of coolant. (I place a bowl under to get an idea of the amount lost.)

When I have checked the header tank it appears full so I bleed the system just to make sure it is full but I don't jack the van up making it fairly quick to do. With someone revving the engine I release the rad bleed screw, wait for coolant to appear, tighten up, then top up at the header tank to replace that half litre.

Half a litre isn't a lot but you need to make sure the coolant was fully topped up before you changed the thermostat and try to measure how much you lose if you are going to use the van without bleeding it afterwards.

[crazyhorse]

Thanks both.

Changed this morn. Lost about a half litre.

Temp gauge back to middle. Running well. Cant manage to get the half litre back in though. Havent bled. Should i?

Let it run for 20 mins all seems good. Will let it cool down and see if i can put it cold

[crazyhorse]

Just did a small bleed.

Waited for engine to cool. Put old coolant in header tank, any leftover into expansion tank. Went to rad a let some air out. Coolant came out.

Got it up to temp, just over half way and fan came on so i think thats it.... hopefully

[Ant-t]

Glad that you got it sorted, also think it's a good idea to bleed the system after working on it. Its always good to have a responsive temp gauge.