seanjordan20

History: I've known my AUX pump was not working for about a year. I finally decided to change it out a last month after redoing my a/c system and alternator backer gasket. Now that I've changed it out my cooling fan comes on for around 5 secs at startup (like its doing a systems check). I don't ever remember it doing that since I owned the car in 07. Does anyone else's do that? I put only around 3k on it last year and it will be less this year since I bought a new car last year but I want to check and make sure. I've been fixing all the little things that's wrong with it trying to get it right for a possible sale if the wife wants to get the G31.

The last two things I have to do on it is the upper oil pan gasket and transmission fluid change. If anyone is close to Augusta GA and want to help out on the gasket change hit me up because I'm dreading it. Lol

donpb

I'm not sure if mine even works because I never see it turn on.

Wait, how the heck can I check my fan at startup? Jump out the car real quick?

seanjordan20

I hear it right when I crank the car (when I'm in the car, that's how loud it is). It blows fast then cuts off. Its not extremely loud but loud enough to hear it cut on the of. I think I remember the fan only turning on when the car hits operating temperature which took about 15 to 20 mins sitting at idle on a cold start.

The crazy thing is I look in INPA and ISTA and all is normal (modules all green). When I run a test in ISTA on the fan and pump it comes back good. My temps are running normal.

donpb

Ok you made me go check. Haha.

I started my car and then got out and ran to the front and my fan wasn't running.

But it never does unless the engine is running really hot. Are you sure your coolant temp sensor or wiring is ok?

seanjordan20

Yes I'm sure everything is good on the car. I don't know what's triggering it. I will connect ISTA again but it's green all the across. I posted my last pull from a couple days ago.

seanjordan20

Did another check and no issues. I going to unplug the aux pump in the morning to see if it still does it.

donpb

Are you 100% sure the noise is coming from the fan?

seanjordan20

Yes I hear it coming on and verified it with my brother watching it. I think it started after me taking the front end apart and redoing the compressor and everything in the front of the engine. It may be because I didn't plug the fan plug in all the way or it needs cleaning. I'm going to do some tests in the morning.

seanjordan20

Ok I ran tests on everything I can think of and even cleaned the plug. Still the same thing. I guess I'll have to wait until something goes to figure this out. Next week I plan on doing a coolant flush and changing out the water pump and thermo. Hopefully after that it clears up. It just might be the fan on its last leg but the tests keep coming back good for it.

donpb

I see a dude on YouTube using a MaxiDAS to turn the fan on / off. The control signal is pulse width modulated, so can't measure with a DVM.

You could have an intermittent connection or a wonky fan.