overheating troubleshooting

[LightlyToasted]

'07 X5 4.8i. Recently overheated in stop 'n go traffic when it was 27C outside. Radiator fan was not on. After it cooled down I was able to drive home on the highway as there was no traffic.



No loss of coolant. When idling the coolant temperature as measured by the hidden dashboard diagnostics climbs steadily past 100C to about 120C before I shut the engine off. Fan does not run (even with AC switched on), and both upper and lower radiator hoses top out at about 99C. One time when I was doing this test I heard a rattling noise which appeared to come from the vicinity of the water pump (which I replaced preventatively 3 years ago), but I haven't been able to reproduce it and put a stethoscope to it.


Suggestions for how to troubleshoot? How can I know for sure that the water pump is working? Can I jumper the fan with 12V to see if it is working, or does it require a signal on the signal wire? Should there be 12V present at the fan connection at all time?

[getty150]

I've been researching this very problem...the fan will not respond to the signal sent from the dme.
Simply put is that fan has an internal component (second stage unit) im sure it can be repaired but with all the trouble one would have to go through, best to simply purchase another fan. Fans are not cheap$$$. Aftermarket fans are hit or miss...I'm sending one back today ($187). I read a lot of posts, general solution...purchase new fan!
I've even tried the boneyard, no luck there -for me-. I've inquired at an electrical repair shop...they were familiar but they informed me the parts can't be purchased and is unique only to bmw.
Haven't called the dealer yet..
we know whats there$$$$!
However, I could inquire with the indy repair shops.

My e83 has been down for a month now...with work and no time for experiments and trials, ive got to bite the bullet....$280 plus bucks...however, I take solace in the fact I've been meeting the bmw repair challenges over the last 6 years successfully. I've saved a considerable amount of money on my own ingenuity.

[LightlyToasted]

Replaced radiator fan. All good now. Fan comes on at idle, and coolant temperature stays at about 102C.


As an added benefit, I had been experiencing sluggish acceleration recently, similar to what was described in this post. I had recently changed the ATF, reset adaptations, and did the adaptation learning routine. I thought maybe I had screwed up the learning routine, as it was hesitant to upshift from 2-3 and 3-4. After replacing the fan, vehicle accelerates normally now. Much better.

[andrewwynn]

1-2 shift sucks when xm is cold maybe also when too warm? Nice feedback though.