E39 M5 Engine Failesafe Mode

[Hedgetrimmer]

Just been out for a sedate drive and the Engine Failsafe Mode came on for the first time. I am nervous about taking it to the stealer and thought about buying a engine diagnosis kit. Peake seems to be a popular one as it is about the price of an hours labour and at least I can use again if another problem occurs.

Anyone bought one and are they good at specifically identifying problems?

Also, just wondering what the general concensus is re typical problems leading to the above message. I assume the main one is the MAF and if so does it identify which bank the problem exists on? What else could cause it. Car was running very smoothly before so hopefully not fuel pump related.

Edited by Hedgetrimmer on Sunday 26th April 18:14

[Hedgetrimmer]

Should read Failsafe not failesafe - cannot work out how to edit title

[Neil.D]

The 'Limp mode' can be triggered by a couple of things. Yes MAF's but more so by CPS (Cam position sensors). These are common.
Presumably your yellow engine light came on too? Sadly the car needs 'reading'. Dealers normally charge £70 or so a time which is just wicked. A specialist will charge half that.
I have a PEAKE R5/FCX(3)which is great. Bought it for £50 from ebay so keep an eye out for one.

But in answer to your question, you cannot really diagnise it without a reader. Plus, MAF's should be replaced in pairs.

[Hedgetrimmer]

Thanks Neil

New inlet and exhaust pulse sensors were fitted nearly exactly 3 years ago (14,000 miles ago). Thanks for the advise on the MAF sensors. Although they are expensive, they seem to be pretty easy to fit.

[Neil.D]

MMM, they of course could have failed again, who knows. If you intend to change the MAFS which I recommend you do yourself, all you need is a T20 security torque. Halfords do the kits.

[humpbackmaniac]

Is it true that the MAFS are the same Bosch Items as VW 1.8 20v Turbo units from 99-06? ie £64 each from VW rather than £204 from BMW?

[Paulburrell]

Click on this link to see what our American cousins experience has been on using the VW replacements.

http://www.m5board.com/vbulletin/e39-m5-e52-z8-dis...

You may have to subscribe to www.m5board.com to gain access to the link. If you haven't already joined then it's a useful source of information on your new toy.

The prices that you have quoted, are they the ones from www.eurocarparts.com as these guys seem to be very competetive for lots of OEM german branded stuff.

Steve

Edited by Paulburrell on Monday 27th April 13:58

[Hedgetrimmer]

Car has Now been into the BMW dealer. Diagnosed as throttle pot on one of the banks. They are going to do the job for £240 after haggling price down by £60 as they were quite!