Sprytny
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| posted on 23/3/10 at 09:53 PM |
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BMW engine problems (overheating...)
A friend of mine has a BMW 3-series (2.5 ci). The car initially had a faulty fan; this meant that it did not actuate when the engine was becoming very
warm. The engine therefore overheated.
Upon replacing the fan (an aftermarket replacement was used), the fan worked for a around 1 week when it then failed again.
Is this a known problem on this car, and is there a known cause for this problem.
I am thinking along the lines of relay, wiring or thermoswitch causing this fault. What would be the most likely reason why the fan keeps failing and
how can it be tested?
It should be noted that the expansion tank has split letting the coolant out. I am not sure if this related, but the overheating probably caused the
expansion tank to split with the over-hot coolant.
Please let me know what people think this might point to.
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locostbuyer83
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| posted on 23/3/10 at 10:42 PM |
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If the tank is split you need to replace it. Dont want your coolant running out as it'll lead to even more problems
Is the fan coupling working properly?
These go quite often and will cause overheating issues...
http://cgi.ebay.co.uk/NEW-Viscous-cooling-rad-fan-coupling-BMW-3-5-7-series_W0QQitemZ250471975857QQcmdZViewItemQQptZUK_CarsParts_Vehicles_CarParts_SM?
hash=item3a514b0bb1
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Sprytny
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| posted on 23/3/10 at 11:03 PM |
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Thanks
Yes, I was thinking this was a well known problem. It is strange though that the fan has failed twice now.
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britishtrident
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| posted on 24/3/10 at 08:07 AM |
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The reason the the expansion tank split is likely to be because the pressure relief valve in the filler cap is stuck and over pressurised the tank.
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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Sprytny
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| posted on 27/3/10 at 02:54 PM |
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fixed...
The thermostat was changed, the radiator exchanged and all seems to be well. Amazing what a faulty thermostat can do!!!
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Chris_
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| posted on 28/3/10 at 01:02 AM |
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????????
The fan is controlled by an output from the ECU. Which takes it's temperature readings from a temperature sensor on the thermostat housing
(depending on model, probably the brown one, the blue is for the instrument cluster)
It would be good to know the details of the overheating (and the vehicle) ie, how hot, how long, what conditions (motorway, traffic etc)
M20's have a tendancy to crack. M50's warp. Either could lead to headgasket problems in the not to distant future.
Oh and the expansion tank really shouldn't have split from pressure.
Sorry to sound down, but these six pots can get a little fragile and i think its best you know. Might be worth getting your mate to take it to a good
garage and ask there opinions.
Chris
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