Goinghuntin Posted July 6, 2010 Report Share Posted July 6, 2010 This happened last year I think, but I can't remember what I did to fix it. Anyway, she drives a '98 Olds van, got the trusty old 3.4 (trusty?) but lately it's been idling close to 2000rpm both in and out of gear. I looked at the throttle body real quick and no cables are sticking anywhere. Gotta be a sensor somewhere I figure. On a side note, dad just repleced the TPS Nathan Quote Link to comment Share on other sites More sharing options...
Ethan Givan Posted July 7, 2010 Report Share Posted July 7, 2010 My moms '03 Montana van has been doing the same thing, but only in Park or Neutral. In gear it drops to normal. No cables sticking on it either. I dont know how to fix it and it doesnt do it all the time so she is living with it for now. Quote Link to comment Share on other sites More sharing options...
Goinghuntin Posted July 7, 2010 Author Report Share Posted July 7, 2010 I dont know how to fix it and it doesnt do it all the time so she is living with it for now. My mom puts up with it too but it annoys me to no end :angry: In fact, she hardly noticed it was running that high until I pointed it out lol She was more concerned with the part rattling that I forgot to pin up the last time I had it torn up under the hood :boo: Nathan Quote Link to comment Share on other sites More sharing options...
Shaun_300 Posted July 7, 2010 Report Share Posted July 7, 2010 More than likely the Idle Air Control valve aka IAC valve. When they fail they can cause high idle, low idle, no idle symptoms. You can try taking it out and cleaning the bore where it sits and giving the valve itself a cleaning. Use brake clean, it works best. If not replace it. If it's not that it could be an upper intake gasket leaking air into the engine. Quote Link to comment Share on other sites More sharing options...
MonsterBuck48 Posted July 8, 2010 Report Share Posted July 8, 2010 start off checking for dry rot on the vacumm lines on the mani, if not then prolly the IAC (idle air control valve) Quote Link to comment Share on other sites More sharing options...
MonsterBuck48 Posted July 8, 2010 Report Share Posted July 8, 2010 start off checking for dry rot on the vacumm lines on the mani, if not then prolly the IAC (idle air control valve) like shaun said above try cleaning the iac first. sometimes they can become clogged Quote Link to comment Share on other sites More sharing options...
Goinghuntin Posted July 8, 2010 Author Report Share Posted July 8, 2010 If it's not that it could be an upper intake gasket leaking air into the engine. Had that done a couple years ago, by a pretty good shop. I trust they did a good job. I totally forgot the possibility of an IAC valve though lol Thanks Shaun I'll be sure to check that out. Nathan Quote Link to comment Share on other sites More sharing options...
Shaun_300 Posted July 8, 2010 Report Share Posted July 8, 2010 You probably had the lower intake gaskets changed for a coolant leak or oil getting into the coolant or coolant getting into the oil. Of course they do change the upper intake gaskets in the process, I would hope. The GM intake gasket set comes with both upper and lower gaskets, along with new lower intake bolts. A way to check for vacuum leaks, gotta be careful! But spray brake clean in light sprays around the upper intake, if you hear the RPM change, you've found your leak. Quote Link to comment Share on other sites More sharing options...
redkneck Posted July 9, 2010 Report Share Posted July 9, 2010 A way to check for vacuum leaks, gotta be careful! But spray brake clean in light sprays around the upper intake, if you hear the RPM change, you've found your leak. An unlit propane torch works good too. Quote Link to comment Share on other sites More sharing options...
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