Another E39 question

[bmwrp8]

guys a little help.Friends e39 was overheating so we bled the rad still the same...checked and saw the aux fan was always in LOW mode and high mode will only kick in if the temp reached 3/4ths which is high! What we did changed the radiator, water pump , thermostat , and fan switch to 81/88'c...still the same. Aux fan will only kick in high mode if the needle reaches almost 3/4ths which is almost overheating. My e34 kicks in high just before the 12oclock position. any thoughts? thanks guys..

[mamilapon]

Check your temp guage against a known good unit..

[bmwrp8]

Check your temp guage against a known good unit..

will try to put in a diff.cluster to see if it changes. will let you know

[bmwrp8]

Check your temp guage against a known good unit..

ok update, just installed a second cluster still the same. 3/4ths before aux.fan kicks in high.bled again still the same. Any ideas??

[rob101]

ok update, just installed a second cluster still the same. 3/4ths before aux.fan kicks in high.bled again still the same. Any ideas??
i am not an expert but i'd be looking to see whether there is a high temp coolant switch that controls the aux.fan. and then seeing whether its working properly.

something like no. 6 http://www.realoem.com/bmw/showparts.do?model=DD52&mospid=47544&btnr=17_0105&hg=17&fg=05

[bmwrp8]

i am not an expert but i'd be looking to see whether there is a high temp coolant switch that controls the aux.fan. and then seeing whether its working properly.

just changed the fan switch(80-88'c) in the side radiator still the same...I wonder if there is a second one...but i guess not.

[rob101]

well maybe, there is a problem with electronic thermostat also.
it shouldn't be going anywhere near 3/4 even if the aux fan is meant to kick in

[bmwrp8]

well maybe, there is a problem with electronic thermostat also.
it shouldn't be going anywhere near 3/4 even if the aux fan is meant to kick in

we've just changed the thermostat too. is there a second one? whats a electronic thermostat?

[rob101]

we've just changed the thermostat too. is there a second one? whats a electronic thermostat?
hmmm i should have really read your first post :-P, no i am pretty sure there is only one :-P

[rob101]

well you've kind of replaced everything but the fan clutch, which means It could be your main fan isn't cooling enough

[bmwrp8]

well you've kind of replaced everything but the fan clutch, which means It could be your main fan isn't cooling enough

how do you check the fan clutch?

[rob101]

how do you check the fan clutch?
http://web.archive.org/web/20060427110524/www.haydenauto.com/fce3.htm
I am pretty sure it should tell you also, on this site if you search. I think that the e39 clutch will be similar in operation to the e34 (bimetallic strip based)

[Bin_jammin]

I'd suspect the fan clutch to be bad. You shouldn't need the aux fan if that's working properly, and the fact that it's coming on late means your primary cooling fan isn't functioning like it should be.

[bmwrp8]

http://web.archive.org/web/20060427110524/www.haydenauto.com/fce3.htm
I am pretty sure it should tell you also, on this site if you search. I think that the e39 clutch will be similar in operation to the e34 (bimetallic strip based)
ok thanks

[bmwrp8]

I'd suspect the fan clutch to be bad. You shouldn't need the aux fan if that's working properly, and the fact that it's coming on late means your primary cooling fan isn't functioning like it should be.

will check..friends e39 is more headache than my e34

[rob101]

will check..friends e39 is more headache than my e34
you wouldn't be the first to say that :-P

[bmwrp8]

guys, fan clutch is new, still the same. aux fan will engage in low speed but temp needle will go as high as 3/4ths then only the aux fan will go high mode.,...any thoughts??? i'm all out of ideas.:(

[bmwrp8]

anyone?