S40 Cooling Fan Questions

Post by **drvolvo** » 11 Jul 2009, 12:03

I have a few questions regarding the cooling fan (s) in my 2001 S40. I say fans because I see two fans under the hood. One towards the passenger side that is white and runs when I turn on the car and turn on the blower in the car. The other fan is closer to the driver side and it is black and it turns on when I turn on the AC. This fan will cycle for 12-18 seconds on and then 12-20 seconds off. Is this cycling normal?

I occasionally notice the engine temperature above the 3 o'clock position when I run the AC. I recently had the engine temp sensor and the thermostat replaced, but just the other day the engine was running a bit hot when I had the AC on. (It couldn't have been more than 80 degrees out, so it wasn't a sweltering day to begin with).

I am wondering if my cooling fan (I assume its the black one?) might not be coming on when it should. Someone told me it could be the fan relay.

Also, the last time I flushed my coolant was at 105K and I am at 140K now, and that was prob 2 years ago. Could I have weak coolant that isn't doing the job?

I am moving to Maryland soon ( I am in RI now) so if the car doesn't like the heat here it sure won't like the heat and humidity there.

Thanks for your help.

Post by **MadeInJapan** » 15 Jul 2009, 10:45

Cycling on and off of that fan does not sound normal... at least like that- if your temp gauge goes above 3:00 then it's time to change out your thermostat and probably your coolant temp sensor right under it...with these replaced, I'd say you'll find things back to normal.

Post by **drvolvo** » 15 Jul 2009, 11:48

That's the weird thing. I just had the the thermostat and sensor replaced and the fan still does that cycling. I'll keep an eye on it. Any ideas as to what might be causing the weird cycling?