BMW M5 Forum and M6 Forums banner

1 - 9 of 9 Posts

·
Shill account for CNS Racing
Joined
·
435 Posts
Discussion Starter · #1 · (Edited)
While driving in the city I don't notice any issues but on the highway say 6th gear on acceleration the car does not have a smooth acceleration there is occasional what seems to be misfires or hesitation every 2 seconds or so. There are no codes on the ECU and my guess is I need to check my iridium plugs with 30k miles on them. Maybe the oem fuel pump?

Anyone have any ideas?
 

·
Registered
Joined
·
6,642 Posts
Can be ignition,fuel or Vanos related...

I know that is not really a help.

Had that on a few cars,one was loose ground wires of the coils,other one was MAF issue,other one fuel filter,other one Vanos timing off....

I suspect this happens in the 2000-3000rpm range?
 

·
Shill account for CNS Racing
Joined
·
435 Posts
Discussion Starter · #3 ·

·
Shill account for CNS Racing
Joined
·
435 Posts
Discussion Starter · #5 ·
Did that start recently or got progressively worse?
Recently for 2 months and has stayed the same. I cleaned the MAF sensors with no difference. Come to think of it my car had the only other sign which was a the blatty exhaust sound much like when my exhaust cam position sensor needed replacing except it happened twice temporarily. One of the sensors may be on the way out since I only changed the exhaust cyl 1-4. I did get misfire codes when this happened twice recently but no cam sensor codes.
 

·
Registered
Joined
·
46 Posts
I had a similar issue on my beast. It was the Maf's causing it. I tried cleaning mine also, which didn't help at all. After I replaced them everything was back to normal. You should try the MAF test is the cluster and see what numbers you get.
 

·
Registered
Joined
·
7,933 Posts
Agree with Vantaam here

I diagnosed a car with this problem in 08 and it was caused by a bad ignition coil. Replaced all 8 on that car. runs like a dream.
 
1 - 9 of 9 Posts
Top