Thermo-Sending unit inquiry

[DSchultz325e]

OK before I go order this part, I've gotta ask this because I just don't get it. OK I've sourced my overheating problems and it turns out its 'supposedly' a faulty sending unit. Now, the Bentley says to disconnect the connector from the sending unit and if the gauge drops, it is faulty. When I disconnect it, it drops to rest position. This is the indicator of a faulty unit? I'm stumped why this would be the answer when it seems like the natural thing for a gauge to do would be to drop when it had no signal...I've also tried to ground the wire to simulate the high engine temp and it pings right to the red. Just seems like this isn't it.

[DSchultz325e]

bdump

[the bob]

Hello,

Hopefully I can help. I am not yet an expert on my new 87 325i but I have read the bentley about 30 times already.

IThey did not give good information on the sending unit with regards to testing the resistance of it at a given temp for reference. So I agree that they left us hanging a bit on that one. Why is it overheating is a better question for you. I would change out the aux fan switch on the radiator and see if that helps. IF not think about changing the fan clutch. Is your radiator clogged up?

I think that it would be an easy starting point to order the switch and see if that cures it. IF you dont mind wasting money order the sending unit as well. What the hell these cars are just hobbies of ours. Sane people dont drive 17 year old german cars. Dont be hung up if you replace a 17 year old 20 dollar part. It wont brake the bank and will satisfy your couriosity.


good luck

buy the switch as after 17 years that surely would not be a foolish purchase.

bob


just remember that when you buy needless parts for your hobby it beats the 2 to 4 thousand a year in depreciation that most people suffer per year