1999 E39 523i - Loss of Power and rough Idle/stalls

[arh]

Hi

I have an intermittent issue with my car (E39 523i SE) which is getting worse. First symptoms a few months ago was that the car would start strangely taking less time that usual or take a much longer time to start - sorry cannot explain this any other way! Driving would then feel very sluggish and response was terrible. On leaving the car for a while and starting again the problem resolved itself.

Recently this has been happening more frequently. Symptoms are the same and usually happens when the car is hot. The turning of the image/starter motor takes longer to start and idle seems rough. Sometimes the car will not hold the revs on start and needs to be started several times whilst holding down the throttle. There is lack of power and only once the car has stalled during driving does the power come back on restart. After this the car behaves normally.

Is this a problem with the ICV, MAF or something more serious?
No warning lights are displayed.
I have noticed that the accelarator sometimes feels heavier - could the throttle cable be the issue?
Thanks.

[Boostist]

Please prefix any technical thread titles with

1999 E39 523i -


as per the posting guide

I would say the first thing you need to do is get the fault codes read from the car....

You wont get any warning lights for most of them as they are stored on the ECU and can only be accessed by a diagnostic hardware being connected.

Heres what to do

http://www.bimmerforums.co.uk/forum/...-why-do-t2383/


and then post them up here and we can help you out..a lot

[karl1171]

I have a similar problem with my car. a 99 523. Starting sometimes takes longer than usual and I'm getting an occasional lack of power exactly as you described.

No problems with the idle or throttle pedal though.

Let me know how you get on if you get diagnostics done!

[doug1234]

Have the battery tested to ensure there is enough power to run the cars electrical system.I have noticed lots of posts over the last year where cars had varying symptoms from rough idle to abs warning lights and trans program and a fair amount of these were because the battery had the volts but was not holding the amps.

[karl1171]

Ok, as an update, I've found when this happens if I turn the engine off and re-start, the problem goes away!

[328mark]

have you had any codes read?
there may be a camshaft sensor fault code stored

[webber]

Hi,
Yeah i had similiar syptoms on my 523i se, turned out to be a crankshaft sensor, not to hard to replace and cost a £81. Get the codes read and see what comes up.
Webber

[webber]

Ok, as an update, I've found when this happens if I turn the engine off and re-start, the problem goes away!

Mine did the same, if i turned it off and left for a few minutes everything would be ok, turned out to be crankshaft position sensor.
Webber

[arh]

It turned out to be both camshaft sensors. One on the exhaust and one on the inlet.