Idle Problems - BMW Forum - BimmerWerkz.com
5-Series (E12,E28, E34, E39, E60) Chat relating to the BMW 5-Series of all generations. Specific models include: BMW 518, BMW 520, BMW 520i, BMW 530i, BMW 528i, BMW 530i, BMW 518i, BMW 524d, BMW 525i, BMW 525e, BMW 528e, BMW 540i, BMW 535i, BMW 520d, BMW 525td, BMW 525d, BMW 530d, BMW 525i/xi, BMW 530i/xi. (BMW 5-Series Forum)

 
LinkBack Thread Tools Display Modes
#1 (permalink) Old 07-07-2005, 10:42 AM
5th Gear Member
 
Join Date: Jul 2004
Posts: 1,028
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
BeelZibub is an unknown quantity at this point
(Thread Starter)
For the last couple of weeks my 98 523 (2.5 ltr m52) has been running crappy at idle. I sprayed a bit of carb cleaner around the inlet manifold and the revs increased slightly - obviously needed a new manifold gasket then!! I've had this replaced today and tried the old carb cleaner test again - no leak, then why the bloody hell does she still idle like a bag of crap???? Idle control valve is likely a culprit but the thing is sometimes she will settle at idle perfeclty and I have to keep revving her to get the bad idle again, other times she will just consistently idle badly - does this sound like an idle control valve issue??? I thought they just died or can they just get a bit sticky? I disconnected the MAF and the idle problem went away, however after driving home with the MAF disconnected the idle problem returned. This might sound stupid but the problem always seems worse when I put her on my steep drive nose facing down <wtf??

Also there is an incessent rattle from the exhaust somewhere which started about 7-8 weeks ago as a little tinkling but now is a major rattle when the engine is started/revved. Last week I had a new hi flow Stainless cat, center box and rear box fitted not just because I thought it would aliviate this problem but because I had promised myself a stainless system for a while. The exhaust was a custom job and uses the down pipes from the original cat, is there anything in these down pipes that could cause a rattle - ie are they double skinned or something or can anyone think of a possible problem with the manifolds??? She had new manifold gaskets about 3 months ago. Just to let you know what the rattle sounds like, it really sounds as if a heat sheild is loose, but this isn't the case, all are in place firmly.

Any help appreciated
BeelZibub is offline  
Sponsored Links
Advertisement
 
#2 (permalink) Old 07-07-2005, 12:36 PM
5th Gear Member
 
Join Date: Sep 2003
Posts: 1,176
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
sp0rky is an unknown quantity at this point
I dont have much time so I'll be quick. I also didnt get to read the exhaust part of your post entirely, so I'll read that and reply (if I can) later.

ICV CAN cause that problem that you are talking about. It's rare for it to be sticky, but it can be .. especially if it's just going on it's way out. Have you checked other vacuum areas? The MAF can definately cause the issue too. But that would cure the idle problems WHILE the engine is cold (each time it was cold) and would go back to crappy when it was warm. Even that, that doesn't garauntee the MAF, because the whole DME reverts back to many default settings.

Another rare issue is the ICM. (Idle control module - controls ICV)

I know the ICV isn't the EASIEST of jobs (not entirely difficult either) but you should try swapping it with a known working unit.

good luck.

sp0rky is offline  
#3 (permalink) Old 07-07-2005, 12:40 PM
5th Gear Member
 
Join Date: Sep 2003
Posts: 1,176
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
sp0rky is an unknown quantity at this point
Ok.. I have more time than I thought

Exhaust - does it happen while driving? Can you locate the sound?
Often times a defective (or broken) catalytic converter can make the heatshield - type thin rattle.

If not, I would just suspect loose or non-existant rubber pieces in the exhaust hangers.

sp0rky is offline  
#4 (permalink) Old 07-08-2005, 08:25 AM
5th Gear Member
 
Join Date: Jul 2004
Posts: 1,028
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
BeelZibub is an unknown quantity at this point
(Thread Starter)
Thanks for the reply.

As far as the idle problem is concerned I don't know which way to go yet - Is it strange that she is not storing any fault codes though. Also when I disconnect the MAF the check engine warning light doesn't come on is this normal, I thought the MAF was quite an important part of the system. Also last week I pulled off each pluglead individually and started her up each time - no fault codes stored!!! Surely running on 5 cyls should create an error???

The exhaust still points to something in the downpipe/manifold. I am getting new stainless downpipes fitted next week to see if this cures the problem - if not it will be new manifolds - then if it should still rattle I will be hanging from a tree by the neck.
BeelZibub is offline  
#5 (permalink) Old 07-08-2005, 09:44 AM
5th Gear Member
 
Join Date: Sep 2003
Posts: 1,176
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
sp0rky is an unknown quantity at this point
ICV will often not throw a code, but it's hard to garauntee.

The MAF doesn't always throw a check engine light, either. Usually only if it's been disconnected for a long time or if it has broken.

As for disconnecting plug leads - as long as they are firing properly - the ECU wont store a misfire code. Disconnect the coil pack completely and thats a different story

sp0rky is offline  
#6 (permalink) Old 07-08-2005, 12:09 PM
5th Gear Member
 
billB's Avatar
 
Join Date: Aug 2004
Location: New Jersey
Posts: 1,635
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
billB has a reputation beyond repute billB has a reputation beyond repute billB has a reputation beyond repute billB has a reputation beyond repute billB has a reputation beyond repute billB has a reputation beyond repute billB has a reputation beyond repute billB has a reputation beyond repute billB has a reputation beyond repute billB has a reputation beyond repute billB has a reputation beyond repute
Send a message via Yahoo to billB
Beelzebub:

Idle control valve is likely a culprit but the thing is sometimes she will settle at idle perfeclty and I have to keep revving her to get the bad idle again, other times she will just consistently idle badly - does this sound like an idle control valve issue???

DEAR Beelz

1st Welcome back to our forum......long time no see.

You remember way back when my engine got flooded and I had to replace it.....the good news I do have an extra ICV sitting somewhere in my garage; the bad news is to find it.....how about this: I will look for it; once found will take a pic or two for you, also I will send you the part number ( I am not so sure if it fits your 523!!!!!...so check it out...it came out of 97 528i......Let me know f it fits please...and it is yours.....

regards

billb
billB is offline  
#7 (permalink) Old 07-08-2005, 12:19 PM
5th Gear Member
 
Join Date: Jul 2004
Posts: 1,028
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
BeelZibub is an unknown quantity at this point
(Thread Starter)
Quote:
Originally posted by billB@Jul 8 2005, 06:09 PM
Beelzebub:

Idle control valve is likely a culprit but the thing is sometimes she will settle at idle perfeclty and I have to keep revving her to get the bad idle again, other times she will just consistently idle badly - does this sound like an idle control valve issue???

DEAR Beelz

1st Welcome back to our forum......long time no see.

You remember way back when my engine got flooded and I had to replace it.....the good news I do have an extra ICV sitting somewhere in my garage; the bad news is to find it.....how about this: I will look for it; once found will take a pic or two for you, also I will send you the part number ( I am not so sure if it fits your 523!!!!!...so check it out...it came out of 97 528i......Let me know if it fits please...and it is yours.....

regards

billb
[snapback]360735[/snapback]

Thanks Bill
BeelZibub is offline  
#8 (permalink) Old 07-08-2005, 12:27 PM
5th Gear Member
 
Join Date: Sep 2003
Posts: 1,176
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
sp0rky is an unknown quantity at this point
As long as both engines are the M52TU, the ICVs are directly interchangeable.

sp0rky is offline  
#9 (permalink) Old 07-08-2005, 02:06 PM
5th Gear Member
 
billB's Avatar
 
Join Date: Aug 2004
Location: New Jersey
Posts: 1,635
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
billB has a reputation beyond repute billB has a reputation beyond repute billB has a reputation beyond repute billB has a reputation beyond repute billB has a reputation beyond repute billB has a reputation beyond repute billB has a reputation beyond repute billB has a reputation beyond repute billB has a reputation beyond repute billB has a reputation beyond repute billB has a reputation beyond repute
Send a message via Yahoo to billB
Thanks Sporky for the good input..I have found it in my garage...reading the black sticker on the ICV:

Bosch
0 280 140 545
1 744 713

Beelz if you are interested in the ICV just PM me with a mailing address (physical or P.O.BOX) and it is my pleasure to give it to you as a gift for a member and a friend who contributed alot of good info. to this forum.......

regards

billb
billB is offline  
#10 (permalink) Old 07-09-2005, 12:59 AM
5th Gear Member
 
CosmosBlack's Avatar
 
Join Date: Jul 2003
Location: Florida
Posts: 1,286
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
CosmosBlack has a reputation beyond repute CosmosBlack has a reputation beyond repute CosmosBlack has a reputation beyond repute CosmosBlack has a reputation beyond repute CosmosBlack has a reputation beyond repute CosmosBlack has a reputation beyond repute CosmosBlack has a reputation beyond repute CosmosBlack has a reputation beyond repute CosmosBlack has a reputation beyond repute CosmosBlack has a reputation beyond repute CosmosBlack has a reputation beyond repute
What about O2 sensors? They cause bad idling when they are turning bad.
And I'm surprised you could still drive the car with the MAF sensor disconnected!? When mine was faulty, the engine kept stalling!

CosmosBlack is offline  
#11 (permalink) Old 07-10-2005, 04:56 AM
5th Gear Member
 
Join Date: Jul 2004
Posts: 1,028
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
BeelZibub is an unknown quantity at this point
(Thread Starter)
Quote:
Originally posted by CosmosBlack@Jul 9 2005, 06:59 AM
What about O2 sensors? They cause bad idling when they are turning bad.
And I'm surprised you could still drive the car with the MAF sensor disconnected!? When mine was faulty, the engine kept stalling!
[snapback]360927[/snapback]
Lol, when the MAF was playing up a bit back I just disconnected it for a couple of days til I could be bothered to sort out the problem - as Sporky said they realise the MAF isn't operating and revert to a set of default parameters which is a "best guess" by BMW when the cars were manufactured. She ran much smoother with it disconnected than with a faulty MAF.


Thanks for all the input, here's an update.

After a week of having mechanics poking bloody great screw drivers around my heat shields, others telling me "it's definetly the down pipes want replacing", others "the manifolds must be rattling somehow", I decided to take off my collar and tie and revert to getting my hands dirty again (It's been a while). Within 60 seconds I had found the source of the rattle - the o2 sensor had somehow come loose and was sitting there rattling and vibrating like a bitch - HOW DID THEY ALL MISS THIS???? Anyhow, I now have a bloody great blister on my thumb from grabbing a hot o2 sensor but after a turn of the spanner I now have no rattle.

The idle problem is definetly on the inlet manifold somewhere. I had the gaskets changed but the problem is still there - A new can of carb cleaner and a couple of squirts around the inlet manifold brings the revs up just a little - it seems to be around cyl 5. I guess this means there is a crack in the manifold :-( I'm not quite sure what to do yet as I haven't got the premises for doing things like removing inlet manifolds and inspecting them - probably wouldn't be able to see a crack anyway.
BeelZibub is offline  
Sponsored Links
Advertisement
 
Reply

  BMW Forum - BimmerWerkz.com > BMW Model Specific Forums > 5-Series (E12,E28, E34, E39, E60)


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
Erratic Idle / Misfire / Cutting out makdolby 3-Series (E36) 12 02-05-2012 07:57 AM
Idle Problems Ronanom 3-Series (E36) 2 11-07-2005 03:24 AM
Idle Problems '95 325is Burnettm 3-Series (E36) 3 04-26-2005 12:41 PM
Idle Problems, Intake Service Bulletin? rhansen162 5-Series (E12,E28, E34, E39, E60) 1 03-06-2005 07:18 PM
318ti Idle Problems losichu 3-Series (E36) 2 10-20-2004 03:44 PM

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 Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome