BMW still not running well..... advise needed.
Discussion
I still think the boot needs checking. It won't take much of a split. A big one will give idle problems and trigger the EML, but a small one will just give drivability issues. If it's pulling air in it will confuse the ECU as it won't all pass through the MAF. You could try disconnecting the MAF and see if things improve.
The fact that sometimes it's running fine and sometimes it's not would make me think it's an electrical issue rather than a mechanical one. I've just done a load of work on my 330ci, including vanos seals, intake boot, CCV, Disa valve etc.
The car is now running better in that I'm getting more mpg and definitely a bit punchier, but it didn't feel particularly bad before the work and was showing no fault codes. Only when I did the work I discovered the intake boot had big holes in it, the CCV was completely blocked and so for the symptoms you describe I would think it's a different problem.
Is the new MAF that you mention a genuine one?
The car is now running better in that I'm getting more mpg and definitely a bit punchier, but it didn't feel particularly bad before the work and was showing no fault codes. Only when I did the work I discovered the intake boot had big holes in it, the CCV was completely blocked and so for the symptoms you describe I would think it's a different problem.
Is the new MAF that you mention a genuine one?
_Neal_ said:
Definitely another vote for getting a proper diagnostic done - that could either be main dealer or good independent. Whereabouts in the country are you, sure someone on here can recommend a garage?
Well I´m from Denmark, so I don´t know if any of you knows a good garage here :-)ADEuk said:
I still think the boot needs checking. It won't take much of a split. A big one will give idle problems and trigger the EML, but a small one will just give drivability issues. If it's pulling air in it will confuse the ECU as it won't all pass through the MAF. You could try disconnecting the MAF and see if things improve.
Boot is fine.... no holes. MAF disconnected.... no improvements... :-(Rsdop said:
The fact that sometimes it's running fine and sometimes it's not would make me think it's an electrical issue rather than a mechanical one. I've just done a load of work on my 330ci, including vanos seals, intake boot, CCV, Disa valve etc.
The car is now running better in that I'm getting more mpg and definitely a bit punchier, but it didn't feel particularly bad before the work and was showing no fault codes. Only when I did the work I discovered the intake boot had big holes in it, the CCV was completely blocked and so for the symptoms you describe I would think it's a different problem.
Is the new MAF that you mention a genuine one?
I agree.... the Grimlin must be electrical..... but when it does´nt throw any codes ????The car is now running better in that I'm getting more mpg and definitely a bit punchier, but it didn't feel particularly bad before the work and was showing no fault codes. Only when I did the work I discovered the intake boot had big holes in it, the CCV was completely blocked and so for the symptoms you describe I would think it's a different problem.
Is the new MAF that you mention a genuine one?
Monty Python said:
At that age I'd be looking for an independent BMW specialist.
Also, I'm struggling to see how resetting the ECU will affect a manual gearbox.
Add - have you checked the throttle position sensor?
If the problem is of an electrical nature, resetting the ECU will clear the stored faults and the car will run default for a while. A problem with the TPS for an example, will effect shifting... also in a manual..... but TPS is a part of the throttle body which was changed to a new original last week..... helped, but did´nt solve the problem.Also, I'm struggling to see how resetting the ECU will affect a manual gearbox.
Add - have you checked the throttle position sensor?
Edited by Monty Python on Tuesday 24th May 11:47
Edited by Monty Python on Tuesday 24th May 11:48
Check all your grounds are tight, remove and refit battery terminals. A poor ground can upset the electrical system and cause firing issues. Also worth checking coils are all correctly fitted. Would expect coil issue to show up in scan tool but may not depending on software. New coils solved our similar issues. Got no codes on snap on reader, but decent mastertech showed them.
I had similar 2003 E46 330ci. Couldn't find anything wrong and it kept losing power randomly when warm. I had only just purchased the car but privately so no come back.
The previous owner had fitted a fancy air filter thing (don't know make/model). Anyway, I didn't need/want nor see benefit from it so removed it and fitted a normal airbox with a new air filter. Problem disappeared! It was the air filter sucking in warm engine air impacting performance (or aleast I think anyway but the issue definitely went away).
I would check the air filter itself, the boot as mentioned by others and generally the pipework surrounding the air intake system. It's free and easy to check and will help eliminate it from investigations.
Do feedback how you get on.
The previous owner had fitted a fancy air filter thing (don't know make/model). Anyway, I didn't need/want nor see benefit from it so removed it and fitted a normal airbox with a new air filter. Problem disappeared! It was the air filter sucking in warm engine air impacting performance (or aleast I think anyway but the issue definitely went away).
I would check the air filter itself, the boot as mentioned by others and generally the pipework surrounding the air intake system. It's free and easy to check and will help eliminate it from investigations.
Do feedback how you get on.
I had similar symptoms to your throttle issue on my E36 M3. If you went full throttle it felt like it was holding back and if you let off a tiny bit it would almost feel like it got more power.
It turned out to be a kinked fuel pipe so when I was demanding full pressure it was having a freak out.
I'd check your fuel filter. Its not an expensive part and relatively easy to change. Certainly will do no harm on that mileage.
It turned out to be a kinked fuel pipe so when I was demanding full pressure it was having a freak out.
I'd check your fuel filter. Its not an expensive part and relatively easy to change. Certainly will do no harm on that mileage.
padhinbed said:
I had similar 2003 E46 330ci. Couldn't find anything wrong and it kept losing power randomly when warm. I had only just purchased the car but privately so no come back.
The previous owner had fitted a fancy air filter thing (don't know make/model). Anyway, I didn't need/want nor see benefit from it so removed it and fitted a normal airbox with a new air filter. Problem disappeared! It was the air filter sucking in warm engine air impacting performance (or aleast I think anyway but the issue definitely went away).
I would check the air filter itself, the boot as mentioned by others and generally the pipework surrounding the air intake system. It's free and easy to check and will help eliminate it from investigations.
Do feedback how you get on.
Mine is an original air filter, and all the hoses are ok... ???The previous owner had fitted a fancy air filter thing (don't know make/model). Anyway, I didn't need/want nor see benefit from it so removed it and fitted a normal airbox with a new air filter. Problem disappeared! It was the air filter sucking in warm engine air impacting performance (or aleast I think anyway but the issue definitely went away).
I would check the air filter itself, the boot as mentioned by others and generally the pipework surrounding the air intake system. It's free and easy to check and will help eliminate it from investigations.
Do feedback how you get on.
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