Idle trouble, only when fan is on
 

At first I thought it was only when the A/C was on, but it happens when ever the fan is turned on. It could be the A/C or the defrost, or the heater, it doesn't seem to matter-when the fan is on it makes a little skip in the idle. I get a miss in the idle (a drop by about 600 rpms) every 6 seconds. Any ideas on what I need to do?

Also, my Bravada doesn't idle very quietly. There's a squealing sound that is very noticeable (but not a really loud screech that would be indicative of a needed belt change). It does seem to be coming from the belt area, though. Any suggestions? I have thought about just replacing the belt anyway. Any tips on doing that?


1997 Oldmobile Bravada

RE: Idle trouble, only when fan is on
 

Replace the belt anyway as you suggested, will atleast eliminate that as a prob. It could also be pully bearings on their way out. You can check those when you change your belt.

As for your Idle prob it sounds like a draw on power. When was your last tune up?

RE: Idle trouble, only when fan is on
 

I'm unsure how to tell if the pully bearings are on their way out. Could you give me some follow-up on that? Thank you.

I recently bought the Bravada (5 months ago) and as a result I have no idea when the last tune-up was. I am getting ready to do a tune up.

RE: Idle trouble, only when fan is on
 

Benado,

I have a similar problem with my 2000 Blazer I can hear a difference in idle like yours but the tach does not move...it happens when the A/C clutch engages and draws power from the altenator. Doing a Tune-up will reduce the problem but not make it go away, because you will be replacing cap, rotor, plugs and maybe wires depending on mileage on your Bravada. I would recomend new wires if the factory wires are still on there and the truck has more than 100K miles on the odometer.

When I did my Tune-up I replaced cap,rotor,plugs and wires. It helped the idle but it did not fix completely.

Just recently while upgrading to the new spyder injection system my friend was watching my A/C clutch engage and he said that he thought my clutch needed replacing because it was engaging lazily...the A/C works also with the defrost settings to speedup the defrost process by dehumidifing the cabin air so the heater works better...this has been done for many years...this is why you can mistake the fan for the problem with your idle...

RE: Idle trouble, only when fan is on
 

Guys don't forget that the AC is going to draw power when it engauges. thats normal. If its trying to engauge alot then it may need a recharge. My Blaze has needed a recharge ever since I bought it. It was trying to engauge all the time, so I unplugged it.

To check the bearings just give the pullies a spin when the belt is off. They should spin freely and quitly.

Benado

For ****s and giggles, try unplugging your AC and then see if it still gives you issues.

RE: Idle trouble, only when fan is on
 

TPS

RE: Idle trouble, only when fan is on
 

---To check the bearings just give the pullies a spin when the belt is off. They should spin freely and quitly.

Benado

For ****s and giggles, try unplugging your AC and then see if it still gives you issues. ---

Thank you. I will try unplugging the AC to see what happens.


Let's say for a minute that the AC clutch is the culprit, is that hard to fix?