YACPT: Yet Another Car Problem Thread

[Doggiedog]

My car temperature when idling seems to increase to about the 75% level. But when I start moving, it goes down to about the 50% level. I'm wondering if this is a sign of a potential problem. I just noticed this yesterday evening. The outside temperature was about 75 degrees and I had my AC on.

Car is a 95 BMW 325i 5 speed w/75K miles.

 

[txgixer]

That happened to me two years ago. The electric fan that comes on with the AC was not working.

You might check your electric fans. Other things to check are your coolant level, over flow level, look for leaks. You might also have a bad thermostat or a weak water pump.

 

[Doggiedog]

Thanks for that tip. One of my friends also said it could be the fan because BMW uses cheap plastic clips to attach the fan and they are prone to breaking. My onboard computer also keeps telling me to check my coolant level but the coolant level is fine so I don't know what to make of that.

 

[Thegonagle]

That's the definitive classic symptom of an electric fan malfunctioning. If the fan comes on when the AC is turned on, you can rule out the motor and most likely, the motor relay. If the fan is controlled by the ECM, then the engine temp sensor is probably bad. If the fan is controlled by a seperate thermo-switch, that's your most likely culprit. Once you locate either of these parts, replacement is generally extremely easy. (See your dealership parts department to find out which part applies to your car.)

 

[Doggiedog]

Thanks Garfang! I'll take a look at it but since I am all thumbs when it comes to cars, I'll probably have to take it into the shop. Know how much it might cost?

 

[Thegonagle]

Probably under or around $100 parts and labor if you have someone else do it.

ED: Assuming the fan, motor, and relay are fine.

ED2: If the fan comes on with the AC, you can run the AC in traffic until you get it fixed properly.

 

[Thegonagle]

Doh! I just re-read that you did have the AC on. Hope for a relay, because those fan motors are 'spensive, probably a dealer-only part.