A/C and idle problem (hopefully the last time)

[sflamedic]

I have been having a problem with theengine stumbling at idle for quite some time. I have changed the plugs and wires twice. The a/c is blows cold but when it starts to stumble at idle the air gets hot. i asked a guy at work who used to be a mechanic and he thought it was low freon. I bought the kit to refill and when i connecte it the reading was in the red and when the a/c cycled it went off the gauge. When i started looking into this problem i checked the fan and it was moving. When he looked at the car for me the fan was not moving. He got a hose and let it run down the front of the radiator and whaaalaaaa the engine ran smooth for the first time in a long time. Do i need to replace the whole fan assembly? Any ideas on what to do from here? Also the car runs fun without a/c on.

[NewPTCruiserInPA]

We got our 06 Cruiser at the end of March, and the first time we turned on the A/C 3 weeks later we had the stumble/shudder in idle. It would blow cold though. It didn't do it at all when the A/C was off. We took it to the dealer who said it was the compressor. After that was replaced, it continued to do the stumble in idle (the rpms would rev up to over 1000, shoot down to 400, and then go back to it's normal idle at 750. It did this every couple of minutes). Only this time, now it was blowing hot air when doing it too!

We took it back and they then said it was the fan module. One of the speeds (I forget which one) was burned out. They replaced the whole thing. We haven't had a problem with it since. Everything blows cold and no more stumble!

[CREWZIN]

Originally Posted by sflamedic

Do i need to replace the whole fan assembly? Any ideas on what to do from here? Also the car runs fun without a/c on.

You don't have to replace the whole fan assembly and motor but you do have to take the whole housing out to replace the motor. I've never seen the motor on sale myself when mine burnt out but someone said Auto Zone sold just the motor so I would think other places like NAPA or Discount Auto would sell it also.

If your handy with tool and don't mind getting your hands dirty, it should only take a couple hours the first time to replace the fan. Do a search on "overheating" in these forums and you'll see plenty of advice on changing out the fan.

[sflamedic]

Would it gradually go out? Like i said it has been doing this for a while and when i checked the fan before it was spinning. Then today it was not. The car isnt overheating either but did a few months ago and i replaced the thermostat housing and refilled the coolant and havent had a problem since. Would it still be a fan motor? i hope that finally fixes this problem.

[sflamedic]

Okay so today i went out to check the fuses, relays, ect. Everything looked good so i started the car to see if the fan was still not working. And to my surprise it was on. It was spinning fast, blowing alot of air and the motor was not hesitating at idle at all. A/c stayed cold too. So i left it in gear, nuetral, reverse and still ran fine. I drove it around stopped for a while at idle and no problems. Is that normal for the fan to work, not work, and work again? Any ideas? How does the low / high speed work on the fan? When does each come on? Thanks for the help. This is driving me nuts and i cant wait to finally fix this.

[CREWZIN]

I've never actually found an answer to when each speed of the fan comes on but I would think (without AC) the low speed comes on when the water temperature sensor first sees the temp rise to a certain temperature and sends a signal to the ECM to turn on the fan. Then if needed, the ECM brings on the high speed fan at a higher water temperature. Both high and low fans are cut off at 35 mph as there is supposed to be enough air through the radiator and condensor to keep the water and AC running well.

With the AC on, either a sensor or the ECM turns the high speed fan on no matter what the water temperature is.

Personally, it doesn't sound like a fan problem that you have. Maybe a sticking thermostat?

[sflamedic]

Okay it worked fine before. Then i just drove it a few miles away and figured let me check the fan again. I looked and sure enough the fan is not on and the car started to do the idle thing again. Any ideas on what causes it to be intermittant like that? Also when i start it the belt kind of chirps for a little bit until the car is warmed up. Any ideas on that? Thanks for all the help so far.

[CREWZIN]

Think your going to have to hook it up to one of the scanners to get a more detailed readout. Not one that just gives the codes but an in-depth readout. One of the modules could be going bad (ecu, pcm or ecm) or maybe it is the fan with an intermittent fault.

Good luck.

Gotta go now, heading back to Florida (from Virginia) early (4am) in the morning.

[sflamedic]

When the fan motor goes, does it go all at once or would it start to fail? Just wondering if thats my issue. If it started to fail then that would make it do what i am experiencing.

[NewPTCruiserInPA]

Ours would do that too. My husband would drive home for lunch and it wouldn't do it when the car had been sitting for half a day, but when he'd leave a 1/2 hour later to go back to work it would start with the stumbling again.