1,6,7,8 - Series and Mini CooperGeneral Chat related to models that do not fit into particular categories above. Please try to put your discussion in more appropriate sections. This section does cover the 1 Series, MINI Cooper and 8-Series vehicles: BMW 830i, BMW 840Ci, BMW 850i, BMW 850Ci, BMW 850CSi, M8, Alpina B12, BMW CS Concept and others.
I was wondering why my car would run much warmer than normal in traffic, so when I got my A/C working, I looked, and the Auxilary fan didn't turn on. I checked it also when it was getting past the middle to about 3/4 of the way before shutting it off, and the fan didn't turn on at all. However, when I jumped out the relays in the fuse box the fan turned on, so I know it works, and it gets power, just never turns on unless I jump it out. So, what sensor controls that fan to tell it to turn on. Oh, and this is a 85 735i.
I jumped out the relay on the fusebox to the fan and it turns on if I jump out relay k1 and relay k6 which are low and hi speeds respectively. THe fuses for both speeds are fine as well. However it doesn't turn on at all when the car is on and getting too warm, on the hi or low speed. So, could the temp switch be shot and not sending the signal to turn it on?
*Edit* Also, when I turn on the A/C it doesn't kick on at that point either, it just stays off.
If you have run through all of the Aux Fan checks on Don Gale's site (the link I gave you) I would then suspect the relay/s. If the fan runs when the temp switch is jumpered then the fan switch is good.
I had an issue with my Aux fan on my e23 as well, but mine made a lot of noise, something was rubbing. I just disconnected mine and drove it for like 3 years like that with no damage to the engine or the components. Just a thought if you can't get it to work!
I have a 96 318IS. I love this car! But I am having a problem. I changed the water pump and the radiator. But for some reason when I let the car sit on with the heat blasted for more then 25 minutes the car starts to over heat and coolant starts coming out of the cap. When this happens I notice the fan does not turn on. If I turn the AC on the fan turns on. WTF!!! If I start driving the overheating issues goes away. Any ideas what this could be. I was thinking the plug thats on the side of the radiator. But I am not sure if this is what tells the fan to turn on when hot. Any help is good help. The fan does turn on every now and then but not consistant. Maybe this switch is bad. How can I jump the switch to test this out. I dont mind my fan being on all the time. I had this on my Integra. But I am new to BMW's and dont want to mess anything up. Help a fellow BMW owner out.
Taking turns on this car far exceeds any front wheel drive car I have ever driven. Can't wait to upgrade to an M3
My 1995 740iL also only overheats in traffic, although a mechanic said it is because the radiator is cracked and leaking.
I am ordering a second hand radiator, but to be on the safe side, can I make my fan also be on the whole time? Would the fan being on the entire time affect anything negatively, ie will it break or burn something out?
In other words, is it safe to jump the fan to stay on the whole time and is it best to make it run at HIGH or LOW speed?
Actually I jumped my fan, and spoke to my mechanic there is nothing wrong with it, expect your wearing the life of the fan quicker. Its great though cause everything is working great in my car now, since doing this. I will need a new Fan Relay, but until I get that I will run it like this. I also here this makes the AC ice cold when you use it. But I guess its really up to you. It works good though.
My experience is that the viscous fan clutch is usually the culprit if she overheats at idle or in traffic. Case in point, I had this condition with my 1988 750 and changing the fan clutch solved my problem. This is a DIY fix and can be done in less than one hour.
A quick way to see if the fan clutch is beginning to fail:
1. Check to see if fluid is coming out from fan clutch. If so, replace clutch
2. Try spinning the fan by hand when the engine is cold. It has to be cold!!
If the fan turns with very little resistance or very difficult to turn, replace clutch.
I'll be posting additional information regarding the fan clutch very soon. I hope this helps for now
I could not find the link to the test but I do have a paper copy with me!!
Overheating can be caused by several things including the thermostat! My assumtion is that you have flushed the radiator as well...
Here it goes...
1. Start the car (cold) with the hood open and note if the fan is turning, increase the engineRPN and note if the fan turns faster and the noise increases. If it does, first good indication, If it does not increase speed/noise, clutch is bad and needs to be replaced. (remember, this must be tested after the car has been off for and extended period, over night , etc).
2. Leave engine running and note if the fan starts the slow down after 2-5 minutes, speed/noise should deminish and even raising the RPM, the fan should not make as much noise as when first starting, if it does slow down, this is the second good indication. If speed /noise doesnot decrease, clutch may be frozen and should be replaced.
3.Leave the engine idle and watch the temperature indicator. When normal operating temperature has been reached, some increase in fan speed/noise should be noted, in particular when the RPM is increased. If temperature is fairly stable and the fan noise/speed increases or cycles, third good indication. If temperature indication continuous to increase, with no increase infan noise/speed, clutch is defective and should be replace.
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