E34 coolant sensor

[bimmerholic]

1992 525i sport auto, M50 engine (with over 225,000mls still a dream)

I had a intermittent overheating prob(once or twice every couple of months) but as soon as I put the heating controls on it went straight down to normal temp also the display often came on 'coolant level'; eventually the rad burst, so I replaced the rad, thermostat & coolant sensor but 'coolant level' keeps coming up on the display, any ideas?
(the 2 wires to the sensor broke off, but I was told that they could be connected either way round?)

[sp0rky]

well the rad, tstat and sensor... you still have the water pump (could leak from the weep hole for a while before it totally fails) and you have quite a bit of hoses there.

Intermittent over heating seems like an air bubble - so might as well check the WP and all hoses.


As for my cars it now has 135,500 (shes a 1990 525)
and the "other 5er" (e39) has 110,000 now. (shes a 1998 528)
Guess it's time for a new one!




--I posted this in the how high is your mileage thread--

[bimmerholic]

Thanks for that but I have found the problem i think! The 'coolant level' warning keeps coming up on the display & only went off when i actually had low level in the reservoir. I disconnected the plug from the sensor & it still comes on; i re-connected it & put a meter across the wires & got a tool with a long shaft & grippers at the end which i grabbed hold of the float & lifted it, the meter read zero & the display came on. When I put the float down the meter read high & the display went out. On checking the old one it worked the opposite way round(correct way) so now I just have to remember if the display dont come on i'm in trouble!!(cant be asked to change it again) Is there anything that could make this happen ie dirty/wet contacts?
The concern is that i believe if i take the new one out it will read correctly so my new query is :am I doing something wrong or is it just gremlins?!?