E39 M5 Throttle problem...
E39 M5 Throttle problem...
Author
Discussion

andy3781

Original Poster:

158 posts

199 months

Wednesday 23rd March 2011
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Hi,

As per title, recently the car has developed a slight hesitation on light throttle and has been going into ENGINE FAILSAFE PROGRAMME mode. It's an intermitten problem and somes day the car seems to lack power then on others its completly different and feels fine. Had the codes read and it's come back as throttle potentiometer problem. The throttle readings were out of sync with each other on the two banks. So had the throttles reset electronically and all was well for a few weeks and the car felt very rapid indeed compared with before. Now however, the problem has returned! It has had this fault in the past but has usually disappeared of its own accord and never threw up any codes in relation to the throttle. The MAF's have been changed not that long ago so ruled them out at the time. I know there are two Throttle Position Sensor's, is that what the codes referring to? Has anyone done this as a DIY and how much of a pain in the rear is it to do? Also how much are the sensors and where is best to get them from that's not going to cripple my piggy bank? Worth replacing both if not too ££££ heavy?

Any help is much appreciated as the car is now on 194k miles, so i'm going to expect problems like this really but i'm just getting ready to sell the car so need it in good working order for the next owner. But, with this don't want to go and spend X amount on hefty labour rates if its something I could do myself.

Many Thanks
Andy

andy3781

Original Poster:

158 posts

199 months

Friday 25th March 2011
quotequote all
Has anyone got any ideas?

_Neal_

2,891 posts

243 months

Friday 25th March 2011
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Sorry Andy I don't, other than to ask whether you've written the MAFs off having tested them, or just because they're new?

Have you posted the same question on M5Board - good technical knowledge on there? smile


Cemesis

771 posts

186 months

Friday 25th March 2011
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If the codes were for the potentiometer then almost certainly that the problem. My old one had an issue with one of those around 135k so I can believe it will become an issue for high milers.

I think its located at the top of the engine and if you spend a couple of hours taking the plenium off you should be able to find them.

andy3781

Original Poster:

158 posts

199 months

Saturday 26th March 2011
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Found a "semi DIY" on m5 board.com which is basically the start and finish of the job so missing the bits that need to come off in between... Can you remember how much the part was and whether you needed an adaptor lead to fit to the new sensor? Apparently the design of the part has changed and needs a new cable, but then BMW have discontinued the lead so I don't understand how I can get this new part to work.

Thanks in advance.

Cemesis

771 posts

186 months

Sunday 27th March 2011
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I never did the the job myself as mine currently work OK. If the car doesn't work currently then take it apart and see what you find, then take the part into BMW and go from there.

Flamingo27

3 posts

182 months

Friday 1st April 2011
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Good luck!