2002 ATX very rough idle

mastershake · Post by **mastershake** » Mon May 25, 2009 3:18 pm

My GF just got a 2002 base ATX last week. Unfortunatly I've been out of town since we picked it up, so i haven't had a chace to go through and do all the standard "tune up" items that you do with a used car, so that may fix the issue we're having, btu i was curious if this is a simple enough fix that yal may know right off what the issue is.

She idles very rough, almost like the idle is too low. To the point that the vibrations inside are so bad the steering wheel shakes, and you can hardly talkover it at a traffic light. But the second you drive off, she runs smooth and quiet like there are no issues!! It does this reguardless if it's in park, neutral or drive.

I'm assuming the usual, vacume leak, IAC, PCV valve, plugs, or a combination of all of those. I'm new to the 2nd Gen so i was hoping this would be a matter of a simple fix that you all know is a common culprit for these cars.

Thanks!!

FYI She has 82,000 miles, is bone stock, and from what i can see the motor mounts look good.

Adionik · Post by **Adionik** » Mon May 25, 2009 4:00 pm

If you're talking about the idle dipping down to as low as 500rpm's at stop lights and such, mine does it as well. I think it might be the IAC, but I have yet to replace it.

mastershake · Post by **mastershake** » Mon May 25, 2009 4:24 pm

Adionik wrote:If you're talking about the idle dipping down to as low as 500rpm's at stop lights and such, mine does it as well. I think it might be the IAC, but I have yet to replace it.

She doesn't have a tac (base model) so i can't tell the exact RPM. But yeah, that's basically what it sounds like it's doing. Nothing seems to make it better untill you drive off.

Paul56 · Post by **Paul56** » Mon May 25, 2009 4:36 pm

mastershake wrote:
Adionik wrote:If you're talking about the idle dipping down to as low as 500rpm's at stop lights and such, mine does it as well. I think it might be the IAC, but I have yet to replace it.
She doesn't have a tac (base model) so i can't tell the exact RPM. But yeah, that's basically what it sounds like it's doing. Nothing seems to make it better untill you drive off.

Have you tried putting it into neutral or twisting the wheel enough to engage the power steering... to see what effect that has?

mastershake · Post by **mastershake** » Mon May 25, 2009 4:51 pm

Nope. I'll try that as soon as i get back in town.

01N3ON · Post by **01N3ON** » Mon May 25, 2009 5:58 pm

My 2001 SE does the same thing. It drops down to 550RPM until I put it in neutral and back to drive. It is kinda like the tranny isn't downshifting as it should. I think I am going to try to replace the tranny fluid and filter. Maybe that will help. I really don't think it is a problem with anything other than the tranny. Once it is back in drive ti idles at 750RPM. What is the proper idle speed for a ATX neon?

Sorry to hijack your thread!!

Daniel

mastershake · Post by **mastershake** » Mon May 25, 2009 6:33 pm

01N3ON wrote:My 2001 SE does the same thing. It drops down to 550RPM until I put it in neutral and back to drive. It is kinda like the tranny isn't downshifting as it should. I think I am going to try to replace the tranny fluid and filter. Maybe that will help. I really don't think it is a problem with anything other than the tranny. Once it is back in drive ti idles at 750RPM. What is the proper idle speed for a ATX neon?

Sorry to hijack your thread!!

Daniel

It's all good. Maybe we can both get our issue fixed!!

I don't think my issue is tranny related though. It does it reguarless what position the shifter is in.

Adionik · Post by **Adionik** » Tue May 26, 2009 2:25 am

The issue is not tranny related. But I can tell you that twisting the wheel will usually get it up, and IMO it doesn't seem to affect anything so I just live with it.

Now the balljoints are another story

mastershake · Post by **mastershake** » Tue Jun 02, 2009 7:51 am

little update. We installed a cluster with the tach yesterday and it appears that i'm idling at the correct RPM (Looks like between 750 and 800 RPM in gear). I checked all the motor mounts and they look like new. Changed the plugs. Ran some injector cleaner through.

Everything seems fine. She runs fantastic. I'm starting to think it's just something we are gonna have to get used to. I did notice the tranny fluid was a little low (just under the hash marks), so i'm gonna top it off since it needs it, and who knows it may make a difference.

srtjesse · Post by **srtjesse** » Thu Jun 11, 2009 7:49 pm

my car does the same shit its really annoying what i do is set it to neutral then put it back in gear i did change the motor mounts and plugs and wires and its stoped doing it then it started to do it again the next day its really frustrating i think it could be a vac leak or iac sensor

Post by **occasional demons** » Thu Jun 11, 2009 8:27 pm

The PCM just readjusted the idle. It prolly picked up a little from the better components. A vacuum leak would make it idle faster/smoother. (Unless it was similiar to the brake booster hose missing)
You could adjust the throttle stop open a bit more to get it to idle slightly higher. It might also seem a bit more responsive when first hitting the go pedal. When I had the IAC on backwards (Mustang TB) it was leaking by the seat. Made throttle response all kinds of jumpy. I think a little more air via the throttle plate would be more controlled.