BimmerFest BMW Forum banner
1 - 5 of 5 Posts

·
Registered
Joined
·
1 Posts
Discussion Starter · #1 ·
Hi, my name is mike, and I'm new to the bimmerfest forum.

I have a question about my 97 528i.
In the hot days of summer ( 90 degrees or hotter ) when I have my AC on and get stuck in
traffic or at a stop light for two to three minutes, the temp gauge starts to climb. If i turn off the AC, and start to move a little, the temp drops.
I took the car in last year to a BMW dealer and they replaced the water pump. At the time I didn't think it was the problem. And about a week later, sure enough, It started again.
Well, when I took it back in to the dealer, the outside temp was about 80 degrees and of course no problems. Well this year same thing again. I don't want to take it back to the dealer again. I don't trust them.

OK. My questions are, the electric fan should run at high speed when the temp clims? Yes?
Mine dose not, at least not all the time. Some times it does, but today, when it started to over heat, I parked it and check the fan speed. It was running at the slow speed.

What tells the fan to increase speed? Is it the computer, or the temp monitor on the side of the radiator? I think the fan's ok, because it will run at high speed. Just not when I really need it to.

The second question is about the viscosity fan. When does that kick in? At ideal i can grab the fan with no problems. Now I have not revved the motor and grabbed the fan. Dumb but not Stupid. And could this be my problem? A bad clutch fan?

Anyways, I hope someone out their has some info on this problem.
Thanks for you help.
Mike.
 

·
Registered
Joined
·
363 Posts
that's idle. yeah, i'd say a new fan clutch. i'll have to take a look at mine at idle. it's the computer and temp sensor (to tell the fan to increase speed). is there any air in your cooling system? i've heard even a little air can cause an air bubble to take-up residence right under the temp sensor -which prevents it from reading actual water temperatures. though i have a little pin hole leak in my radiator expansion tank and my fan'll still whirl hard if it needs to. maybe they improved the design between 97 and 02.
good luck
 

·
Registered
Joined
·
1 Posts
Have noticed the same syntoms on my 98 528i.
Plan to change the anti-freeze cos it hasn't been changed in years.
Will let u know if it fixed it.
 

·
Registered
Joined
·
641 Posts
It does sound like the fan clutch... Try a couple things. first I would add a bottle of water wetter. then replace the thermostat... then the fan clutch...
 

·
Registered
Joined
·
15,460 Posts
Most likely fan clutch but.........

97528I said:
Hi, my name is mike, and I'm new to the bimmerfest forum.

I have a question about my 97 528i.
In the hot days of summer ( 90 degrees or hotter ) when I have my AC on and get stuck in
traffic or at a stop light for two to three minutes, the temp gauge starts to climb. If i turn off the AC, and start to move a little, the temp drops.
I took the car in last year to a BMW dealer and they replaced the water pump. At the time I didn't think it was the problem. And about a week later, sure enough, It started again.
Well, when I took it back in to the dealer, the outside temp was about 80 degrees and of course no problems. Well this year same thing again. I don't want to take it back to the dealer again. I don't trust them.

OK. My questions are, the electric fan should run at high speed when the temp clims? Yes?
Mine dose not, at least not all the time. Some times it does, but today, when it started to over heat, I parked it and check the fan speed. It was running at the slow speed.

What tells the fan to increase speed? Is it the computer, or the temp monitor on the side of the radiator? I think the fan's ok, because it will run at high speed. Just not when I really need it to.

The second question is about the viscosity fan. When does that kick in? At ideal i can grab the fan with no problems. Now I have not revved the motor and grabbed the fan. Dumb but not Stupid. And could this be my problem? A bad clutch fan?

Anyways, I hope someone out their has some info on this problem.
Thanks for you help.
Mike.
Overheat at stop light but not hwy speed usually means fan clutch being the suspect.
A partially closed thermostat can produce this symptom too.

Better yet, doing the entire cooling system. I did the whole cooling system and posted it at:

http://bimmerboard.com/forums/posts/199986

Read through the post carefully. Everything you need to know is there.

Also read the post that I forgot a few pictures:

http://bimmerboard.com/forums/posts/200161

Hope this helps.

cn90
98 528i 90K
 
1 - 5 of 5 Posts
Top