BimmerFest BMW Forum banner
1 - 20 of 20 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter · #1 ·
Hey Guys,

Hope someone had this problem and was able to fix it.

Well this has been happening for some time now. I blew my valve springs and I brought the car in to get it fixed. it was supposedly fixed and everything was replaced. but now I get this car shaking problem. When I first start the car, it works fine, no shaking but when I leave it on for a period of time... maybe 15-30 mins. the car just starts to shake out of no where. It doesn't always happen but it's just random when it happens. I could be driving fine but when I get to a stop light or just stop for a second. It'll start shaking. my RPM while idling is at less than 1000.

Also, when the car starts shaking. and I'm about to go after stopping at the red light. when I step on the gas pedal. for some reason the RPM goes negative (meaning if its at 1000k it'll decrease as I step on the pedal), If I keep pressure on it while it's going down, my car stalls out if I dont release it.

The car starts shaking hard. I dont know, maybe it can be a bunch of numerous things? another I noticed is that, after I do a oil change on the car, it rarely happens but when it comes time to change the oil again... the car starts the shaking again?

Anybody have this problem or maybe could help me figure out whats wrong with it? :eek:
 

·
Registered
Joined
·
7 Posts
I have an 02 540 with similar problems. After an expensive trip to the dealer and a crankcase vent valve change, still have the problem. With the car in D, at a complete stop with a foot on the brake, the problem is most severe, but it does not happen all the time. Several replies have suggested it is a vacuum leak. I am going in for service to check.
 

·
Registered
Joined
·
15,784 Posts
Take it back to the guy who did the valve job. Something is not right. If the car ran OK before the job, it's something he did wrong.
 

·
Registered
Joined
·
7 Posts
Thanks for the reply. Unfortunately, the problem was there before and after the expensive CCVV replacement. Given the sporadic occurance and only at idle, it seems like it would be vacuum related. I was surprised the dealer in Nashville was unable to correctly diagnose the problem. I am not a mechanic, but I would assume a BMW dealer could dial into the problem in short order.
 

·
Powered by BMW
Joined
·
249 Posts
make sure fuel system is not clugged..check on vacume leak.and ignition system.
vibration on happens when the car is at idel,right?once u give it some gas,it runs smooth and fine,right?
 

·
Registered
Joined
·
13 Posts
i had a problem on my 540 for a while and it was a vacuum leak... the car would shake at idle and run really roughly but at higher speeds it wasnt a problem. would also dip negative rpms when i pressed on the gas but the leak on my car was so bad with mine that it would actually stall every once in a while.
 

·
Registered
Joined
·
628 Posts
does the check engine light possibly light up? if so, might check to see what system/s are being affected. you should be able to plug a standard OBD reader in and find something to point you in the right direction. but if you arent so handy with engine problems you might as well take it to an auto tech.
 

·
Registered
Joined
·
61 Posts
Good advice so far...

I worked at an indy German shop for 5+ years and have seen this symptom caused by several different things.

First, you need to eliminate the ignition system from potential causes. Clearly, the car needs to display the rough idle while you perform these tests. Pull the cover so you can see the coil packs. Unplug the connectors one coil at a time. If the idle gets worse, that cylinder is functioning. If the idle is unchanged, the associated cylinder is not functioning.

Once you identify the problem cylinder, swap coil packs with a functioning cylinder and see if the miss moves to the new one. If so, it is the coil/plug wire. If the miss stays on the original problem cylinder, look for a vacuum leak around the intake plenum serving the misfiring cylinder.

To do this, you can spray brake cleaner along any suspect seals with the engine running (have a fire extinguisher on hand just in case). If the cylinder picks up, the vacuum leak is present at the location you just sprayed. Then it is a matter of replacing the appropriate gasket.

If none of this works or helps, try using deoxit d5 cleaner on all of your sensor connections (a little goes a loooonnnng way) Start with your MAF sensor.

http://www.amazon.com/CLEANERS-LUBR...8&s=musical-instruments&qid=1269970343&sr=8-1

This is magic in a can and has solved many electrical problems when other shops wanted to replace electronics.

Hope this helps.
 

·
Registered
Joined
·
4 Posts
Discussion Starter · #10 ·
i had a problem on my 540 for a while and it was a vacuum leak... the car would shake at idle and run really roughly but at higher speeds it wasnt a problem. would also dip negative rpms when i pressed on the gas but the leak on my car was so bad with mine that it would actually stall every once in a while.
DoBeMotors - That is the exact problem that I am having! where was the vaccum leak at? I'm not good with cars but I do love to try to work on them. My apologies that I'm a newbie but I would really be happy fixing the problem myself instead of bringing it into the shop and having to pay so much again for it. Not being cheap but I don't make that much anymore. Did you fix the issue yourself DoBeMotors?

Thanks you guys for all the advice given!!!!
 

·
Registered
Joined
·
7 Posts
Thanks for the continued great ideas. Based on all I have read, but not yet taken in for diagnosis, a vacuum leak sounds most like everyone else who has experienced the problem. Is it safe to assume that if I take the car to a qualified, non-dealer mechanic and tell them I am looking for a vacuum leak causing the described problems they will know what to do?

Interestingly, I read another thread about someone experiencing hard downshifts into 1st (automatic) and I experience the same intermittent, but frustrating problem. His suggested cure was to increase the RPMs with the AC off and car in D. As an experiment on the way to the office this morning, I increased the RPMs to about 650 with the car in D and the misfires and rough idle stopped. I know that does not fix the initial underlying problem but sure makes for a more enjoyable commute. Are there any risks to just increasing RPMs?
 

·
Registered
Joined
·
7 Posts
There are several references on this thread to the SES. Interestingly, it has not come on. I did check, during start, to be sure the bulb is good, which it is. Just rough idle that does not occur above 650 RPMs.
 

·
Registered
Joined
·
4 Posts
Discussion Starter · #13 ·
oh yea, this is another thing that I noticed when it does start to "shake" when I come to a complete stop at a light. it'll idle and start shaking. when I take off while it "shakes" I shift gears (I have a stick), I have to actually get at a higher speed before I can shift to the next gear up. like for say for 2nd gear, I'd have to be at 35 mph or higher before shifting into 3rd gear or else the car will start shaking really bad and so forth. but when im at 5th gear (last gear) and I'm going at 70 or so, it's fine. I hope it's a vacuum leak. I have no clue about fixing it but I'll probably have to do some research to see where the vacuum leak could possibly be if that is the cause.
 

·
Registered
Joined
·
34 Posts
Sounds like a vacuum leak to me but I also think you should heed the advice of Topgear 454. That will go a long way to pinpointing the exact problem. don't rule out your cam positioning sensor and also your ICV. Like topgear said use the process of elimination to determine the problem .Good Luck
 

·
Registered
Joined
·
17 Posts
I have a similar problem with my 2001 525i wagon. It will run like silk, and then all of a sudden start shaking, and dropping rpm at idle. The engine stalled out a few times while this was occurring.
I also notice an occassional "popping " sound, like it is backfiring. I sprayed some cleaner around the plenum, and hear a "click"in the plastic armature atttached to the head, and suddenly it runs smooth as silk again. Then, when it seems the cleaner has worn off, it starts to show the same symptoms again.
I just changed the fuel filter, and couldn't believe the black crud that was in there. I plan on cleaning the injectors, and then see what happens. Does this sound familiar to anyone? Any suggestions? Air flow problem? Is there a solonoid that could be the problem?
Thanks.
 

·
Premium Member
Joined
·
17,427 Posts
In addition to the obvious vacuum leak, it can also be the Camshaft Positioning Sensor (CPS).

mw
 

·
Registered
Joined
·
17 Posts
Would it make more sense to first replace the CPS that applies to the intake cam or the exhaust cam, or both? 130. vs. 37. Thanks. :dunno:
I noticed when I sprayed cleaner around the manifold adjusting unit, I heard a click, and the car ran smooth until the cleaner wore off. Can anyone tell me if this part could cause these symtoms?
Thanks. :eeps:
 

·
Registered
Joined
·
7 Posts
2002 540i rough idle

Thank you to all for the advice, direction and assitance solving the problem with rough idle on my 2002 540i. After spending money to replace the CCVV, only to find that it did not need to be replaced, thanks BMW of Nashville, I carried the car to a trusted local independent shop. After several hours of diagnosis, it was determined the number 2 ignition coil was bad. Following the replacement the car is running like new.

The local servicer was stummped when he got into the diagnosis because there was no SES light on and no faults were being thrown. When in P and idling, there is no detection of a problem. It was not until the technician put the car in R to pull it out of the garage for a test drive did the misfire start. At that point he was able to reconnect the computer and determined the problem. After some manipulation of ignition coil 1 and 2, he pinpointed it to 2 and repaired.

I know this is a very frustrating problem based on the number of threads. Best of luck to all who are still working toward a solution.
 

·
Registered
Joined
·
173 Posts
Thank you to all for the advice, direction and assitance solving the problem with rough idle on my 2002 540i. After spending money to replace the CCVV, only to find that it did not need to be replaced, thanks BMW of Nashville, I carried the car to a trusted local independent shop. After several hours of diagnosis, it was determined the number 2 ignition coil was bad. Following the replacement the car is running like new.

The local servicer was stummped when he got into the diagnosis because there was no SES light on and no faults were being thrown. When in P and idling, there is no detection of a problem. It was not until the technician put the car in R to pull it out of the garage for a test drive did the misfire start. At that point he was able to reconnect the computer and determined the problem. After some manipulation of ignition coil 1 and 2, he pinpointed it to 2 and repaired.

I know this is a very frustrating problem based on the number of threads. Best of luck to all who are still working toward a solution.
Thanks for the thread

I'm going through it with my 93 740iL

Already replaced the fuel pump and filter
(still idles rough and up to 1500 rpm it stumbles)
cleaned the MAF, IAT, ICV, and throttle body
(same results)

Check for vac leaks and no issues
ran the car with the MAF, and then the o2 sensors unplugged with no change

I suspect one of the coil packs is giving a weak spark
although no CEL, (I don't have a code reader for BMW OBDI anyways)

so I'll do a test tomorrow by unplugging one coil at a time :thumbup:
if not that, then the CPS would be the next bet

not sure how to test that

oh and I already put in new plugs
 
1 - 20 of 20 Posts
Top