325ci Throttle Valve Issues?

[CypherP]

Hi all,

Not sure whether anyone can help out a bit here, but i have a bit of an intermittent fault with my 2002 325ci. Upon cold starting, i occasionally find that it suffers a fluctuation in idle speed, with very little response from the throttle. The trouble im having is that once the ignition is switched off, and left for a few minutes, when re-starting, the problem goes away. This has been happening 2-3 times a week for the last fortnight, but doesn't persist.

When it does occur, i have the EML light and engine warning light appear, but they then disappear once the car is re-started and the problem goes. I have had this diagnosed by an independant specialist, and an auto-electrical friend, who both confirm the fault code to be P1632 - Throttle Valve Adaptation - Adaptation Condition Not Met. Before i have to fork out over the odds to get Vines to re-diagnose, i wondered if anyone knew of this fault, or any common causes. BMW have said it could just need a new Throttle Valve, but Throttle Body and other areas have also been mentioned.

Any ideas? I'd really appreciate the help, as i love my car and would be good to have some more advice before i spend more to get her running the way she was again.

Many thanks

[CypherP]

bump..

any help would be appreciated

[sniff diesel]

Is it worth giving the throttle body a bit of a clean?

[CypherP]

I havent tried doing that yet. Not being the most technically minded, is it something thats difficult to do/access, or is it relatively easy to take off and re-assemble?

I have read a few threads about people cleaning them out and throttle response being smoother, but i wouldnt know exactly what needs to be done and what to look for.

I appreciate the help. Any further recommendations are appreciated

[Shropshiremike]

Battery in good nick?

[scott10005]

I think this fault code can also be caused by a bad connection at the electronic throttle housing, guessing its a m54 engine??,there was a modified engine loom that was available that included a new throttle housing connector which looked more like a "L" shape rather than pushing straight onto the housing,the ones i looked at you couldn't see the fault but once a new loom was fitted the fault never re-occured,there is also a small chance it may require a new housing as well but that is very rare. You could try removing the connector from the housing,just one locking tab and try increasing the force the pins are held into the connector with,do not spray with wd40 this will make the problem worse. It would be worthwhile phoning your local dealer and asking if the were able to diagnose the fault and submit a goodwill claim on your behalf

[taznuv]

The battery comment is interesting as my 325 very occasionally has a fluctuating idle, and I believe the battery isn't great. I'll be changing the battery shortly so will report back. Mine does it if I let the revs drop too low when say reversing. You dip the clutch realising it might stall, the engine instead of just coming back up to a smooth idle, revs up to about 1300-1500rpm, then down to 500, back up again, then sometimes stops. You restart and it's fine. Is the theory that when the revs drop if the battery is poor the volts drop to low and can cause a problem? I'm also going to check out the wiring loom.

cheers

[CypherP]

Thanks for the comments guys. I've had the car since June, and i must admit, i havent checked the battery, so that will be step one. I will also have a look at the connectors and possibly clean the throttle body if this is easy enough to do.

The issue I have seems to occur when the car is first started. I don't get any idle fluctuations when im driving and the car is running normally. As I'm unsure how long ago the battery was replaced, i may replace this and see if thr problem comes back. Annoyingly, this problem hasn't re-occured in the last few days, and as its such an intermittent fault, its difficult to try and narrow down the causes.

Do any of you know how easy it is to look at/replace/clean the wiring loom and throttle body? With previous cars, i've found my way around home maintenance without too many problems, but this doesn't seem quite so straightforward

Thanks again for everyones help.

[CypherP]

scott10005 said:

I think this fault code can also be caused by a bad connection at the electronic throttle housing, guessing its a m54 engine??,there was a modified engine loom that was available that included a new throttle housing connector which looked more like a "L" shape rather than pushing straight onto the housing,the ones i looked at you couldn't see the fault but once a new loom was fitted the fault never re-occured,there is also a small chance it may require a new housing as well but that is very rare. You could try removing the connector from the housing,just one locking tab and try increasing the force the pins are held into the connector with,do not spray with wd40 this will make the problem worse. It would be worthwhile phoning your local dealer and asking if the were able to diagnose the fault and submit a goodwill claim on your behalf

Any ideas how much the modified loom would be? Vines thought on first description that it might be the throttle valve itself that could be causing the problem, but seeing as 90% of the time it drives perfectly, i was thinking it may be something else thats making it play up.

[scott10005]

Off the top of my head i think its about £350 for the loom,its the whole engine loom and it looks a bigger job than it is,still takes an expert like me 2 hours. Still think its best to get a dealership to check it,least then u have some comeback if the fault re-occurs,rather than a bunch on speculators in a forum

[CypherP]

scott10005 said:

Off the top of my head i think its about £350 for the loom,its the whole engine loom and it looks a bigger job than it is,still takes an expert like me 2 hours. Still think its best to get a dealership to check it,least then u have some comeback if the fault re-occurs,rather than a bunch on speculators in a forum

Very true. Thanks for the info, its appreciated. Really, i was trying to gain a few rough ideas before taking it to Vines and paying over the odds for them to tell me something i may already know. Think im going to replace the battery anyway seeing as i have no idea when this was last replaced, and also have a go at cleaning the throttle body, as this has been mentioned in a few places ive looked. At the moment, i havent had the problem reoccur, but if this still causes problems, then i'll take it to Vines and see what they think.

Thanks again guys.