» Site Navigation | | » Recent Threads | 1999 M3 Swap 09-07-2023 10:10 PM 05-02-2024 08:18 PM 6 Replies, 330,664 Views | | | | | | | 06-14-2010, 10:32 PM | #1 | Senior Member Join Date: Apr 2010 Location: Roanoke, VA Posts: 472 | Rough idle - yes I searched As the title states I've read all that I could on the rough idle but still not 100% what im after. As you can guess my car has a rough idle but to an extent also continues as I drive. I can barely feel it as im driving. Almost like a slight shimmy or something. As I sit and idle its an in and out rough feel. Ny finace says she dosnt notice it but I do. The hotter it is outside the less it does it. This morning at around 70° it was slightly more noticable than this afternoon at around 90°. Just seems smoother as it gets hotter outside. Ive checked all hoses and replaced the plugs. Havnt gotten to the wires yet since im broke paying for my wedding. Ive pulled the PCV valve and cleaned it inside to where it was spotless. Still nothing has changed. Any ideas would be appreciated since I will be taken the 318 on my honeymoon and dont want to be stuck on the highway. Thanks in advance!! EDIT: What im asking is that if you have had the exact same problem and replaced 1 certain sensor to solve it or made an adjustment please let me know. I hate to go and dish out a bunch of money and replace different things when all I needed was one item. EDIT: Also, the previous owner was only runing 87 octane. I switched to mid grade and have only been useing Shell gasoline since all the others around here are garbage and stalls out other cars including my fiances. I put some seafoam in the gas in hopes of cleaning any injectors that might be clogged. Last edited by Bobtail_Bimmer; 06-14-2010 at 11:11 PM. | | | 06-14-2010, 11:01 PM | #2 | Senior Member Join Date: May 2005 Location: PA Posts: 1,906 | I'm no expert but I kinda had a rough idle issue too. Not as you describe but nonetheless, I check my spark plugs to find oil with every plug, after changing them, the idle was smooth as can be. Now, it starting to act up again because I haven't solved the issue (valve cover gasket). Plan on doing that this weekend. Hope that helps a little! __________________ | | | 06-14-2010, 11:08 PM | #3 | Senior Member Join Date: Apr 2010 Location: Roanoke, VA Posts: 472 | LOL I was just reading about the oil on your plugs. My car is not leaking oil and when I changed the plugs the old ones were clean. They were worn but useable. I just make it a point that when I buy a used vehicle that I change all fluids, plugs, wires, ect. I just get real anal about how my cars run and this is driving me crazy. It should be smooth and purring like a kitten!! Thanks for the heads up though. | | | 06-15-2010, 06:06 AM | #4 | Senior Member Join Date: Mar 2005 Location: Portland Or Posts: 2,666 | Vacume leaks. Take the rubber air tube between the throttle body and the air flow meter off, and clean it, you'll likely find little cracks in the bellows, its like 29 bucks at the dealer and raises hell when it wears out. Dave __________________ Dave - PDX 1995 318ti - Active Black and Tan. 2005 330xi - Mtech 1 - 6spd - Orient Blue/Black | | | 06-15-2010, 10:35 AM | #5 | Senior Member Join Date: Apr 2010 Location: Roanoke, VA Posts: 472 | That was one of the first things I checked and I did find some cracks. I used a rubber epoxy and sealed them up for the time being. Guess I should look at replacing. Thanks. | | | 06-16-2010, 10:49 AM | #6 | Senior Member Join Date: Apr 2010 Location: Roanoke, VA Posts: 472 | Anyone else? Ideas? New boot was not the issue. | | | 06-16-2010, 05:24 PM | #7 | Member Join Date: Feb 2006 Location: Montreal Posts: 63 | There's a tiny vac hose that makes a 90 degree downwards comming out from a tube from the upper intake in the front. It's so small that perhaps you may be missing it ot it got unplugged. | | | 06-17-2010, 01:20 AM | #8 | Senior Member Join Date: Apr 2010 Location: Roanoke, VA Posts: 472 | Thanks ti. I will go and double check that! | | | 06-17-2010, 03:43 PM | #9 | Member Join Date: Mar 2010 Location: chicago Posts: 42 | check the hoses and check the belts, my belt went bad and it gave an impression of rough idling when it was just really a noise making me paranoid lol | | | 06-17-2010, 11:25 PM | #10 | Senior Member Join Date: Apr 2010 Location: Roanoke, VA Posts: 472 | Thanks for the response. Belts were checked first thing and its not a sound. Its an actual feel. I believe I might have found it. There is a hose running from the back of the upper manifold to the idle controle valve that is cracked. I didnt catch it on my first inspection since its hidden pretty good. Local BMW dealership says they will have the hose for me by Monday. Guess I will see if its the culprit once it arrives. | | | 06-24-2010, 12:14 PM | #11 | Senior Member Join Date: Apr 2010 Location: Roanoke, VA Posts: 472 | Just a heads up to those not in the know. Im sure all the verterans here have either delt with it or know about it. I found that one thing and it was a hose that runs from the back of the upper intake manifold directly underneath it to the idle controle valve. I have the M42 if your wondering. Takes less than an hour to replace if you know what your doing. Just remove one end of the hose that runs from the PCV valve, remove your intake boot then your upper intake manifold. Try not to lose or damage your IM gasket or just replace it while you are there. You dont have to disconnect everything from the IM. Just move it enough so that you can get under it. Be sure to put everything back and dont over torque your bolts. That simple. | | | 06-30-2010, 09:36 AM | #12 | Junior Member Join Date: Jun 2010 Location: Honolulu, Hawaii Posts: 7 | | | | 07-03-2010, 11:50 PM | #13 | Senior Member Join Date: Apr 2010 Location: Roanoke, VA Posts: 472 | Nice link. Thanks! | | | 07-04-2010, 10:11 PM | #14 | Junior Member Join Date: Jun 2010 Location: Honolulu, Hawaii Posts: 7 | did mine .... changed the two hoses connecting to the icv changed the hose from the engine valve cover to pcv valve sprayed the icv with throttle body cleaner and lightly brushed engine does run smoother... | | | 07-06-2010, 01:46 PM | #15 | Senior Member Join Date: Apr 2010 Location: Roanoke, VA Posts: 472 | Quote: Originally Posted by kidashley25 I get rough idles on cold mornings but my M will smooth out after 20- 30 seconds of warm up at idle. I would check the rubber intake boot that goes to your intake manifold they tend to dry rot and split on the bottom if you have any holes or cracks in it it would cause your car to run crappy. ___________________________________________ K&N 63 SERIES AIRCHARGER COLD <link removed> AIR INTAKE KIT | I already replaced the boot with a new one. All it ended up being was a hose running from the back of the upper IM running to the ICV. After I fixed that it was fine. I went back yesterday and pulled the ICV and cleaned per the suggestion above for good measure. Last edited by 1996 328ti; 09-07-2010 at 02:34 AM. Reason: link removed | | | | | Currently Active Users Viewing This Thread: 1 (0 members and 1 guests) | | Posting Rules | You may not post new threads You may not post replies You may not post attachments You may not edit your posts HTML code is Off | | | |