| Author | Message | ||
     Jon Dyer (Jmd) New Member Username: Jmd Post Number: 5 Registered: 11-2003 |
on the weekend I removed and cleaned the IAC (stepper motor) after reading a few of the posts on IDLE problems. I also replaced the fiber gasket between the stepper motor and the plenum. However, now there is a high pitched whine coming from the motor when it reaches 3k rpm - I'm wondering if this is an air leak from the gasket I replaced.. If anyone has any suggestions on how to check this they would be appreciated. Cheers, JD | ||
| Jason McCombs (Jasonmc) Member Username: Jasonmc Post Number: 157 Registered: 06-2003 |
i think i have this same whine..Is it more or less quiet but persistant? while you are in the cabin does it sound like its coming from the area behind the radio? i have no idea what causes the whine in my rig but i would love it to go away.. | ||
| Jon Dyer (Jmd) New Member Username: Jmd Post Number: 6 Registered: 11-2003 |
that sounds like it exactly - it kicks in around 3k and yep kind of sounds like it's behind the radio in the engin bay. (ie. where the stepper motor is fixed to the plenum) | ||
| Jason McCombs (Jasonmc) Member Username: Jasonmc Post Number: 163 Registered: 06-2003 |
ok john we got the same damn whine. any other folks got the same sound? where does it come from? | ||
| Don Johnson (Dl_johnson) New Member Username: Dl_johnson Post Number: 2 Registered: 02-2004 |
From your descriptions sounds like an air leak. I am assuming both y'all have 3.9s with the stepper in housing that attaches to the back of the plenum, not the new style on the throttle body. You can spray carb/throttle body cleaner, while the engine is running, around the stepper and housing to check the gaskets; if the rpms rise gasket(s) are definitely suspect. Also might check to see that the bolts securing the housing are good and tight. Might be worth removing the housing to check the gasket between it and the plenum. I have read on lrx.com of a case where that gasket failed. Hope this helps. | ||
| Jon Dyer (Jmd) New Member Username: Jmd Post Number: 8 Registered: 11-2003 |
thanks Don - I was thinking that it might be an air leak.. (especially as it was me who pulled out the stepper motor - in the first place) Jason - let me know if you manage to fix the whine.. I'll give those fixes a try this week. | ||
| Jason McCombs (Jasonmc) Member Username: Jasonmc Post Number: 164 Registered: 06-2003 |
don mines a 96, its a 4.0. john are you sure your 96 has a 3.9? i thought all 96's were 4.0 the stepper on the 96 is on the front side of the plenum. | ||
| Don Johnson (Dl_johnson) New Member Username: Dl_johnson Post Number: 3 Registered: 02-2004 |
Jason, I did think all 96s were 4.0s with the stepper at the front. But I still think it is probably a air/vacuum leak, so the carb cleaner test still applies, just use it at all places air can get into the system. Also might check all the vacuum lines for cracking/deterioation. I focused on the stepper with Jon since the whine appeared after replacement. I am just spewing my best ideas since it is hard to diagnose w/o hearing the sound. | ||
| Jon Dyer (Jmd) New Member Username: Jmd Post Number: 9 Registered: 11-2003 |
Jason - actually my truck is a '95 I made a mistake when I entered the user profile - I should change that... I haven't yet fixed the whine - I seem to be having trouble locating the right replacement gasket - that is the one for the stepper motor, not the stepper motor housing.. |
