Clunking when shifting now - just did belt

I recently helped a neighbor with his '02 GA with the 3.4 Replaced the hazard switch, as well as the serpentine belt. Now the motor/trans are clunking quite a bit when shifting into gear.

I'm wondering if one of the trans mounts could have torn when I lifted the engine to remove the motor mount. Has this happened to anyone else? Does a bad trans mount sound like the culprit?

Thanks for any ideas.

Steve H.

You would have to lift the engine very high to break the trans mount(s). Though it is possible one or both were already broken or damaged as they are flimsy.

Are you certain the engine mount is tight & torqued?

You can look down by the firewall on the drivers side and see the rear trans mount. The front one is hard to see because of the wire harness and rad. hose.
With the engine off and cold try rocking the motor back and forth and see if theirs any play.
If you get it up on jack stands you might see them better, you just need to be carefull rocking things when on jack stands. ;) A real PITA to replace btw.

Well I didn't put 2 and 2 together until this morning (I think). When he brought the car over, the check engine light was also on. I used a scanner and got a code for the IAT sensor circuit. Took note of that, then erased the code. Later was checking the sensor and found a nick in the wiring insulation by the connector. Repaired the nick, and taped up the wiring better.

Then the car shifted fine.

I checked all of the mounts thoroughly this morning and they all look in top shape. Not any cracking, dryness, splitting at all.

The car shifts fine right now. My neighbor took it and is going to report back if things change.

So how is the IAT sensor changing the shifting?

Steve H.

Glad it was an easy fix!

Its more along the line of the short causing other issues which in turn caused the shifting troubles. When the PCM gets the signals all jumping around it cant figure out what to do or how to do it basicly.

And both the IAT and MAF can cause similar issues if shorted or faulty.

The check engine light came on again (Tuesday eve) - P0113 Iat circuit. So I replaced the sensor ($12) as well as the pigtail ($14) on Wed. I have no way to check/scan real time info from the IAT sensor (although I could have checked voltages at the connector), so at this point I'm hoping that it's all good. No call back so far.

Steve

p0113 will set if pcm reads -38F for more than 3 seconds, (open in signal wire) :) so pcm was thinking that it is really really cold outside and was adjusting shifting points according to false incoming cold air temp. reading. She could probably notice more power when accelerating.