Guest GrandPrixlover1 Posted November 11, 2008 Report Share Posted November 11, 2008 I was just wondering if loose motor mounts could cause my engine to idle rough...I have a 3100. It runs good and gets great mileage, the only thing is, is that when the car is idling, sometimes it idles a little rough. Ever since I tightened up the motor mounts a couple days ago it has stopped, but what else should I look for(besides vacuum lines) as far as causing the engine to rough idle if it continues? My roomate who knows quite a bit about cars says that my bushings on the mounts(dogbones) could be going out. Any suggestions.... it doesn't happen everytime the car is idling either...some days it does it, and some it doesn't. thanks for any help. Quote Link to comment Share on other sites More sharing options...
spiderw31 Posted November 11, 2008 Report Share Posted November 11, 2008 It could be the mounts (including the dogbones), although bad mounts won't cause a rough idle, they will just transmit more of the movement / vibration when they can no longer control it. When you say rough idle, do you mean that you just feel / hear the engine more than before? Or do you mean that the engine moves and rocks noticably more and possibly sounds different? If the first, it could be the mounts. If the second, you might have a bit of a misfire, and I'd start hunting that down. Also don't discount the fact that you may have bad mounts that are more visible as such with a misfire. Quote Link to comment Share on other sites More sharing options...
Guest GrandPrixlover1 Posted November 11, 2008 Report Share Posted November 11, 2008 the engine sound is different...revs to a thousand then back to 700 rpm on it's ownm for a few minutes and doesn't stop until I give it some gas. and I can feel it vibrate the whole front end of the car. Quote Link to comment Share on other sites More sharing options...
spiderw31 Posted November 11, 2008 Report Share Posted November 11, 2008 Yeah that doesn't sound to healthy. Your mounts may be bad, but they aren't causing your issue, merely amplifying it. How recently have you performed maintenance, and what was done? Quote Link to comment Share on other sites More sharing options...
GP1138 Posted November 11, 2008 Report Share Posted November 11, 2008 the engine sound is different...revs to a thousand then back to 700 rpm on it's ownm for a few minutes and doesn't stop until I give it some gas. and I can feel it vibrate the whole front end of the car. If you need help give me a call and we'll look at it, since I know you're local. Check the IAC valve, unplug it and see if the engine smooths out. Also run some injector cleaner through it, and possibly seafoam it. Quote Link to comment Share on other sites More sharing options...
Guest GrandPrixlover1 Posted November 11, 2008 Report Share Posted November 11, 2008 last oil change which was about three months ago I ran Sea Foam through the gas tank, crankcase(before I changed the oil), and pcv valve. Plugs were changed a little before that and the wires. about another 3 months before that I got some throttle body cleaner and cleaned the Throttle body and throttle plate...the plate and inside the throttle body still looks shiny and clean . "cs1138"...I live in Athens now...as I am attending Ohio University and living on campus...but I'm coming home for winter break next Friday, and I'll be home for the next six weeks(until the 3rd of January). And thanks, if it continues and I've got some time I'll come on over(I'd call first, but I don't have your number) and let ya take a look at it. I don't know if this might be a helping cause the problem but when I changed the three front plugs, somebody cross threaded the #2(old plug)...even though we had a little trouble getting the new plug in we got it. Quote Link to comment Share on other sites More sharing options...
Guest GrandPrixlover1 Posted November 16, 2008 Report Share Posted November 16, 2008 bump Quote Link to comment Share on other sites More sharing options...
spiderw31 Posted November 17, 2008 Report Share Posted November 17, 2008 Oh sorry... somehow lost track of this thread Anyways, does it only run poor at idle, or does the problem also randomly occur off idle as well? If you are having this issue at closed throttle only, my old 6000 had a problem very similar and it turned out to be a cracked vacuum line. I know you said originally "other than vacuum lines", but just lettin ya know where the problem was with mine. It could be something vacuum related for you as well. Also it could be the IAC is failing or dirty. When you cleaned the throttle body, did you clean it and its passages as well? Quote Link to comment Share on other sites More sharing options...
Guest GrandPrixlover1 Posted November 17, 2008 Report Share Posted November 17, 2008 i'm kind of ignorant on this but what is an IAC...maybe I can clean it, if I knew what, and where it is, and how to clean it. Yeah I said other than vacuum lines to try and rule out vacuum lines, but yo umay be right. I've been thinking vacuum lines for a while, I just wanted to know if it was something other than that. Well everything will be fixed before I sell the car so. Once school lets out and I get home and get a job I'm gonna save up some money to fix her, and then give her a good home. I don't sell lemons...PERIOD!!! Quote Link to comment Share on other sites More sharing options...
spiderw31 Posted November 17, 2008 Report Share Posted November 17, 2008 IAC = Idle Air Control, and you should find it on the back of the throttle body. Quote Link to comment Share on other sites More sharing options...
Guest GrandPrixlover1 Posted December 15, 2008 Report Share Posted December 15, 2008 I just figured out what was causing my rough idle. It wasn't vacuum lines, or my IAC etc... It was my fuel filter! I was changing my rear struts today, and they were SHOT!! And I decided to change the fuel filter as well since Grismer said it needed to be changed, well I checked it first and it was clogged. So when he put one on and I drove around a bit it was gone Quote Link to comment Share on other sites More sharing options...
5speedz34 Posted December 15, 2008 Report Share Posted December 15, 2008 Wow! I bet it was original or nearly original! Quote Link to comment Share on other sites More sharing options...
Guest GrandPrixlover1 Posted December 15, 2008 Report Share Posted December 15, 2008 yeah and it was rusty, not totally, but it sure was clogged...probably due to not having enough money for gas and running the gas tank almost to empty, more than once. Now I just have to see about my Tranny pan. I pulled the car out of the garage and there in front of me was the most smallest puddle of red lying there on the floor. First I'm going to see if the bolts on the pan just need tightened up, then if it still leaks or if the bolts are already tightened, I'm most likely gonna have to replace the gasket and repack the CV joints, which is only about a seven-ten dollar DIY. Quote Link to comment Share on other sites More sharing options...
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