Thread: 'interesting' temp gauge readings

I'd be checking/cleaning all the earth points you can find to start with, especially in the engine bay.

I think I solved the problem....must have as it has not done it again....the higher than usually heat I think was due to an 'air lock' or similar, I did replace the temp sender and by doing so water did come out of course and I think that created an air pocket.
I removed the sender again, letting water out once again, also with the header tank cap off, then I squeezed the hoses to try and get rid of any possible air pocket, there was a lot of bubbling and gurgling going on when I was squeezing the hoses, I then let it settle for a while, topped up the header tank and its been fine since then, so here're a set of crossed fingers!!

I too have found that they can be a right pain to bleed. I've found that having the car facing uphill helps (maybe that's just my car though).

However, that doesn't explain your rapid guage fluctuations.

Originally Posted by Scouse

I too have found that they can be a right pain to bleed. I've found that having the car facing uphill helps (maybe that's just my car though).

However, that doesn't explain your rapid guage fluctuations.

yes very true...it could still be a bad earth problem that is intermittent....great!?!?!

Head gasket? Hopefully not.

hhhmmmm....don't think so, oil looks clean, no traces of water.....

just an update...after eliminating the 'air lock', things did work better, but I noticed that the gauge would sometimes still move erratically.....I then swapped the pressure cap on the header tank and it now seems to be all OK...I drove during the last weekend when the heat here in Melbourne was severe to say the least with aircon running, no more erratic movements and steady on the halfway mark....so it looks as though a combo of a possible air lock and a dodgy pressure cap

i had same problem once with temp gauge ,once outside temp showed 28 or higher on your climate control lcd display in cabin next to gearshift it would go into the red ,but i know use to sit between 1/4 and 1/2 .again like you had no heating isues (never had ),but had slow starting problem it was time for new battery .put in a new battery same slow turnover ,harry at bossley park auto eletrical put a new earth cable from battery to alternator bracket,but left original earth cables alone (have extra dual earth now)after that extra earth cable temp gauge sits between 1/4 (cold days ) under 1/2 (hot days , running frount twin fans when air con swiched on ,makes hell of a difference cooling ) so now back to normal and as a bonus starter motor spins faster and car feels faster ( computor not starved of electical current now ) so if you still have bad readings do what i did worked for me ,cheers.