Welcome to Bimmerfest -- The #1 Online Community for BMW related information! Please enjoy the discussion forums below and share your experiences with the 200,000 current, new and past BMW owners. The forums are broken out by car model and into other special interest sections such as BMW European Delivery and a special forum to voice your questions to the many BMW dealers on the site to assist our members!

Please follow the links below to help get you started!

Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > 5 Series > E34 (1989 - 1995)

E34 (1989 - 1995)

Reply
 
Thread Tools Display Modes
  #1  
Old 10-29-2012, 06:15 AM
Beats4bimmers Beats4bimmers is offline
Registered User
Location: Tallahassee,FL
 
Join Date: Oct 2012
Posts: 10
Mein Auto: 90 525i, 00 528i
Weird Engine Stutter When Idling?

Whats up Everybody! I am the new found owner of a 1990 BMW 525i, I picked it up for $1000 bucks and while it's not perfect, I have brought it back to life at least to daily driver status. It was slow as hell and grumpy at first, struggling to get to 50 - 60 mph even. Paint looks REALLY good minus the rear bumper and a little rust on the bottom passenger side front door.

Front seats need some love, could use a headliner but it's not horrible or an immediate concern. Dashboard and door panels are surprisingly near mint. My brother has a 92' and his door panels are pretty much gone. I have come to the conclusion that someone loved on the car for a long time before giving up on it. Now on to the mechanical issue...

When I first picked it up, the car would give a rough "jerk" when sitting at red lights or stop signs, and sometimes it would even stall but fire back up immediately. Since purchasing a month ago I have replaced the fuel filter, spark plugs, plug wires, intake boot, blower motor and drier filter(has nothing to do with engine issue) all blown fuses, Oil and filter with some restore, a radiator flush because there was straight water in it, and i'm waiting on a distributor cap and rotor.

Since doing all of these things, the car will now at least drive and shift through the gears very smoothly when accelerating. Highway driving will cruise the car along at 80-85 mph with ease. It's when you're in the city and sitting in constant stop and go traffic when all hell breaks loose.

I can't seem to figure out why the car does the jerking when idling, and only when idling. When I reach a red light, I put the car in neutral to keep it from cutting off. But once I'm back in drive, everything's all good again? What do you guys think could be causing this problem? I've ruled out a bad fuel pump since it starts everytime, and usually fuel pumps either work or they don't. It seems more electrical, but outside of the distributor cap and rotor that I'm waiting on, I'm clueless as to where the problem might be coming from. Plus since all of the minor maintenance that I have performed, the jerking is not so bad, kinda intermittent. Its like I have ironed out most of the wrinkles with a few pesky ones left.

Please thrown me some insight! Peace.
Reply With Quote
Ads by Google
  #2  
Old 10-29-2012, 07:05 AM
BMR_LVR's Avatar
BMR_LVR BMR_LVR is offline
Humble E34 lover
Location: Asheboro, NC
 
Join Date: Dec 2008
Posts: 5,264
Mein Auto: 1992 525i
Welcome to the Fest!

I'm not all that familiar with the M20 engine, but I suspect that your idle control valve either needs to be cleaned (likely) or replaced (less likely).

Do a quick search on this forum for the Bentley manual. It will help you with this and almost all problems you will encounter with these fine automobiles.

Again, welcome.
__________________
Most problems are usually something simple !

Quote:
Originally Posted by noego View Post
It's Deja Poo - as in, I've heard this **** before.
Steve

Calypso Red 1992 525i with 200K miles

1991 735i - Sold
1992 525i - Sold
1995 325is - Sold
2000 528i - Sold

Reply With Quote
  #3  
Old 10-29-2012, 11:44 AM
down19992000 down19992000 is offline
Officially Welcomed to the 'Fest
Location: nc
 
Join Date: Feb 2010
Posts: 116
Mein Auto: 1995 525i
Quote:
Originally Posted by Beats4bimmers View Post
Whats up Everybody! I am the new found owner of a 1990 BMW 525i, I picked it up for $1000 bucks and while it's not perfect, I have brought it back to life at least to daily driver status. It was slow as hell and grumpy at first, struggling to get to 50 - 60 mph even. Paint looks REALLY good minus the rear bumper and a little rust on the bottom passenger side front door.

Front seats need some love, could use a headliner but it's not horrible or an immediate concern. Dashboard and door panels are surprisingly near mint. My brother has a 92' and his door panels are pretty much gone. I have come to the conclusion that someone loved on the car for a long time before giving up on it. Now on to the mechanical issue...

When I first picked it up, the car would give a rough "jerk" when sitting at red lights or stop signs, and sometimes it would even stall but fire back up immediately. Since purchasing a month ago I have replaced the fuel filter, spark plugs, plug wires, intake boot, blower motor and drier filter(has nothing to do with engine issue) all blown fuses, Oil and filter with some restore, a radiator flush because there was straight water in it, and i'm waiting on a distributor cap and rotor.

Since doing all of these things, the car will now at least drive and shift through the gears very smoothly when accelerating. Highway driving will cruise the car along at 80-85 mph with ease. It's when you're in the city and sitting in constant stop and go traffic when all hell breaks loose.

I can't seem to figure out why the car does the jerking when idling, and only when idling. When I reach a red light, I put the car in neutral to keep it from cutting off. But once I'm back in drive, everything's all good again? What do you guys think could be causing this problem? I've ruled out a bad fuel pump since it starts everytime, and usually fuel pumps either work or they don't. It seems more electrical, but outside of the distributor cap and rotor that I'm waiting on, I'm clueless as to where the problem might be coming from. Plus since all of the minor maintenance that I have performed, the jerking is not so bad, kinda intermittent. Its like I have ironed out most of the wrinkles with a few pesky ones left.

Please thrown me some insight! Peace.
Possibly a vacuum leak? Do you hear a kind of whistling sound when you accelerate?
Reply With Quote
  #4  
Old 10-29-2012, 11:57 AM
BMR_LVR's Avatar
BMR_LVR BMR_LVR is offline
Humble E34 lover
Location: Asheboro, NC
 
Join Date: Dec 2008
Posts: 5,264
Mein Auto: 1992 525i
Quote:
Originally Posted by down19992000 View Post
Possibly a vacuum leak? Do you hear a kind of whistling sound when you accelerate?
Good call Down.

OP, you can test for this by spraying carb cleaner in the areas of the intake boot and associated hoses while the car is idling. If the idle suddenly goes up, then you have found the area of a vacuum leak.
__________________
Most problems are usually something simple !

Quote:
Originally Posted by noego View Post
It's Deja Poo - as in, I've heard this **** before.
Steve

Calypso Red 1992 525i with 200K miles

1991 735i - Sold
1992 525i - Sold
1995 325is - Sold
2000 528i - Sold

Reply With Quote
  #5  
Old 10-29-2012, 01:20 PM
Beats4bimmers Beats4bimmers is offline
Registered User
Location: Tallahassee,FL
 
Join Date: Oct 2012
Posts: 10
Mein Auto: 90 525i, 00 528i
Hmmm... The intake boot is brand new, but I did not spray the hoses associated with the intake boot when replacing it. I only checked for cracks etc. However, when accelerating, there is no whistling or weird engine noises at all.

The car accelarates perfectly, which to me is weird being that the moment you come to a stop is when the intermittent jerking happens. And it somewhat subsides, I say somewhat because it does not stop altogether, maybe 97% when I put the car in neutral. I assume its because the engine revs a little higher in neutral than it does in drive, so that's what I have been doing when I come to red lights to keep the car from jerking/stalling lol. It's annoying, but it'll have to do until I get this thing figured out.

Luckily the radiator and water pump were already replaced I assume, being that those things look newish. As does the starter. Either way, I love this car, and I have hopes of doing a full restore on it inside and out. Once I get past this jerking issue.
Reply With Quote
  #6  
Old 10-29-2012, 01:51 PM
BMR_LVR's Avatar
BMR_LVR BMR_LVR is offline
Humble E34 lover
Location: Asheboro, NC
 
Join Date: Dec 2008
Posts: 5,264
Mein Auto: 1992 525i
Quote:
Originally Posted by Beats4bimmers View Post
Hmmm... The intake boot is brand new, but I did not spray the hoses associated with the intake boot when replacing it. I only checked for cracks etc. However, when accelerating, there is no whistling or weird engine noises at all.

The car accelarates perfectly, which to me is weird being that the moment you come to a stop is when the intermittent jerking happens. And it somewhat subsides, I say somewhat because it does not stop altogether, maybe 97% when I put the car in neutral. I assume its because the engine revs a little higher in neutral than it does in drive, so that's what I have been doing when I come to red lights to keep the car from jerking/stalling lol. It's annoying, but it'll have to do until I get this thing figured out.

Luckily the radiator and water pump were already replaced I assume, being that those things look newish. As does the starter. Either way, I love this car, and I have hopes of doing a full restore on it inside and out. Once I get past this jerking issue.
Your description here again leads me to lean toward a dirty or faulty idle control valve (ICV). However, double check all of the other hoses and spray them with carb cleaner as well. On the M50, The ICV is buried under the intake and pretty difficult to get to without removing the intake assembly (it can be done but is very difficult so I've heard). Again, I'm not too familiar with the M20. It may be easier to get to. Perhaps it would only require a good cleaning. Google "BMW M20 idle control valve cleaning" and you should get some good resources. It may even be on youtube. Also, get a hold of that Bentley manual. It will be extremely helpful.

Good luck and I hope this helps.

EDIT: I pulled up the Bentley manual and on page 113-2, it shows a picture of the idle control valve (#2) on the M20 and looks to be a piece of cake to get to. Page 130-12 tells how to check it.
__________________
Most problems are usually something simple !

Quote:
Originally Posted by noego View Post
It's Deja Poo - as in, I've heard this **** before.
Steve

Calypso Red 1992 525i with 200K miles

1991 735i - Sold
1992 525i - Sold
1995 325is - Sold
2000 528i - Sold


Last edited by BMR_LVR; 10-29-2012 at 02:26 PM.
Reply With Quote
  #7  
Old 10-29-2012, 04:26 PM
BMWFatherFigure's Avatar
BMWFatherFigure BMWFatherFigure is offline
Old School
Location: Perth, Western Australia
 
Join Date: Aug 2012
Posts: 2,171
Mein Auto: E23;E30;E38;E32;E34 +
+1 on ICV. Leaks don't come and go.
__________________
Good - Fast - Cheap: Pick any two.
Current:
E23 735i; E32 735iL (X 2 - 1 Alpine White and 1 Glacier Blue); E34 535i; E38 735iL; R50 Cooper; R55 Cooper Clubman.
Previous:
E21 318i; E30 318i; E32 735iL; E34 535i; E38 730iL; E53 4.4i
Reply With Quote
  #8  
Old 10-29-2012, 05:16 PM
robertobaggio20 robertobaggio20 is offline
Banned
Location: earth
 
Join Date: Oct 2009
Posts: 3,403
Mein Auto: car
While doing the ICV (which is indeed child's play on the m20, relative to the m50), it might be good to clean out your throttle position switch and its sensor. You merely need contact cleaner for this. It is unlikely to be a contributor to this situation, but it takes less than 5 minutes to do and it occassionally causes some problems so please do get to that along the way.
Reply With Quote
  #9  
Old 10-29-2012, 05:31 PM
Beats4bimmers Beats4bimmers is offline
Registered User
Location: Tallahassee,FL
 
Join Date: Oct 2012
Posts: 10
Mein Auto: 90 525i, 00 528i
You guys are the best! I'll get to these things this weekend! Thanks a million, I have hope...
Reply With Quote
  #10  
Old 10-29-2012, 05:39 PM
Beats4bimmers Beats4bimmers is offline
Registered User
Location: Tallahassee,FL
 
Join Date: Oct 2012
Posts: 10
Mein Auto: 90 525i, 00 528i
Check the pics, i'm no photographer! Iphone camera is okay I guess!
Attached Thumbnails
Click image for larger version

Name:	IMG_1099.jpg
Views:	34
Size:	233.7 KB
ID:	347698   Click image for larger version

Name:	IMG_1105.jpg
Views:	32
Size:	217.8 KB
ID:	347699   Click image for larger version

Name:	IMG_1109.jpg
Views:	26
Size:	254.2 KB
ID:	347700   Click image for larger version

Name:	IMG_1110.jpg
Views:	25
Size:	225.6 KB
ID:	347701   Click image for larger version

Name:	IMG_1112.jpg
Views:	29
Size:	236.0 KB
ID:	347702  

Click image for larger version

Name:	IMG_1113.jpg
Views:	31
Size:	252.6 KB
ID:	347703  
Reply With Quote
  #11  
Old 10-29-2012, 06:15 PM
BMR_LVR's Avatar
BMR_LVR BMR_LVR is offline
Humble E34 lover
Location: Asheboro, NC
 
Join Date: Dec 2008
Posts: 5,264
Mein Auto: 1992 525i
Quote:
Originally Posted by Beats4bimmers View Post
Check the pics, i'm no photographer! Iphone camera is okay I guess!
Nice. Post 'em up on the pictures sticky
__________________
Most problems are usually something simple !

Quote:
Originally Posted by noego View Post
It's Deja Poo - as in, I've heard this **** before.
Steve

Calypso Red 1992 525i with 200K miles

1991 735i - Sold
1992 525i - Sold
1995 325is - Sold
2000 528i - Sold

Reply With Quote
  #12  
Old 10-29-2012, 09:23 PM
BMWFatherFigure's Avatar
BMWFatherFigure BMWFatherFigure is offline
Old School
Location: Perth, Western Australia
 
Join Date: Aug 2012
Posts: 2,171
Mein Auto: E23;E30;E38;E32;E34 +
Good looking! Now to make it RUN as good as it looks!
__________________
Good - Fast - Cheap: Pick any two.
Current:
E23 735i; E32 735iL (X 2 - 1 Alpine White and 1 Glacier Blue); E34 535i; E38 735iL; R50 Cooper; R55 Cooper Clubman.
Previous:
E21 318i; E30 318i; E32 735iL; E34 535i; E38 730iL; E53 4.4i
Reply With Quote
  #13  
Old 10-30-2012, 11:18 PM
hollywood95 hollywood95 is offline
Registered User
Location: Tallahassee
 
Join Date: Dec 2011
Posts: 12
Mein Auto: 2002 BMW 325CI
Wow I'm in Tallahassee & having the exact problem. I have no mechanic skills at all but I have some hope by reading this tread.
Reply With Quote
Reply

Bookmarks


Forum Navigation
Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > 5 Series > E34 (1989 - 1995)
Today's Posts Search
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On



Forum Jump


All times are GMT -7. The time now is 02:19 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
© 2001-2011 performanceIX, Inc. All Rights Reserved .: guidelines .:. privacy .:. terms