E39 M5 misfire
Discussion
Hi all,
In my quest for an M5 (and not a Golf GTi) I looked at a mint condition W plate with only 55k miles, FBMWSH and comms pack etc last week. The leather wasn't even worn on the driver's bolster AND I averaged about 23mpg for the first part of the test drive.
Reaching for my cheque book as we turned back on the country road to head back, the road was now clear - so I did what the M5 was made for and set about ruining the fuel economy.
Second gear, foot to the floor from low speed at it pulled to 5,000 rpm as it should, then the engine management light lit up and it felt like 300bhp had been robbed from the engine from there to the red line and at any revs after that had happened.
There was a significant misfire when I applied throttle from this point on.
Has anybody experienced anything like this? Any ideas what it might have been?
We arrived back at the seller's premises and turned the engine off and back on again, misfire gone...
Looking at the service invoices it looked like the previous owner had spent about £500 every other month at a main dealer to cure a similar problem, the last of which IIRC was simply replacing a spark plug over a year ago...
The seller took it to a "normal" garage whose diagnostic machine did not recognise the fault code and so they reset the memory.
My question is, should I be running a mile?
I wanted to take it to the local dealer to examine, but will they still be able to call up that fault if the memory was reset?
The car really is in nice condition, the clutch is the best I've come across. The previous owner clearly spent loads. Any views would be greatly appreciated... Otherwise I'll be calling VW to put a deposit on a lovely two year old 20k mileage GTi. Hmmm.
In my quest for an M5 (and not a Golf GTi) I looked at a mint condition W plate with only 55k miles, FBMWSH and comms pack etc last week. The leather wasn't even worn on the driver's bolster AND I averaged about 23mpg for the first part of the test drive.
Reaching for my cheque book as we turned back on the country road to head back, the road was now clear - so I did what the M5 was made for and set about ruining the fuel economy.
Second gear, foot to the floor from low speed at it pulled to 5,000 rpm as it should, then the engine management light lit up and it felt like 300bhp had been robbed from the engine from there to the red line and at any revs after that had happened.
There was a significant misfire when I applied throttle from this point on.
Has anybody experienced anything like this? Any ideas what it might have been?
We arrived back at the seller's premises and turned the engine off and back on again, misfire gone...
Looking at the service invoices it looked like the previous owner had spent about £500 every other month at a main dealer to cure a similar problem, the last of which IIRC was simply replacing a spark plug over a year ago...
The seller took it to a "normal" garage whose diagnostic machine did not recognise the fault code and so they reset the memory.
My question is, should I be running a mile?
I wanted to take it to the local dealer to examine, but will they still be able to call up that fault if the memory was reset?
The car really is in nice condition, the clutch is the best I've come across. The previous owner clearly spent loads. Any views would be greatly appreciated... Otherwise I'll be calling VW to put a deposit on a lovely two year old 20k mileage GTi. Hmmm.
Mass air flow sensors, and crankshaft or camshaft position sensors are the usual suspects with this sort of thing. None are big jobs, but the air flow sensors are quite expensive, there are two of them and they're £200+ each from BMW. Also possible, but less likely, is a failing fuel pump.
I would keep looking. As has been said, it could be something really minor, or it could be a persistent electrical gremlin, which are notoriously difficult to track down. My own guess would be the MAF (there are 2), failing. Can be replaced for VW (Bosch) parts for around 55 pounds a piece, but let the seller fix it at his cost, before even going further with this if you are still keen. I would personally go for a face-lift car...
Broccers said:
Buy the VW unless you want to spend large.
Well call me a chicken, but today I put a deposit on a two year old MkV GTi with less than 20k on the clock, the 18inch Monzas and a 3 year VW warranty included. Oh and they've thrown in a free ipod connection.Think I will save for an M5 to use as a second car...
Thank you all though!!
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