N52 Hesitation/flatspot 5000 RPM+

T

thecookie125

Member
Morning all, strange issue my car seems to have developed recently, occasionally beyond 5000rpm it will suddenly hesitate with an audible change in exhaust note like the cars holding back, if you keep the throttle depressed it will come back on song but not all the time, as soon as you change gear it goes away.

Recently changed the CCV, one of the post cat O2 sensors and cleaned and rotated the Vanos solenoids as preventative maintenance, one of the solenoids did sound like it was moving freer than the other when I had cleaned them but you could still hear movement. The car also has no codes pending or stored.
 
thecookie125 said:
Recently changed the CCV, one of the post cat O2 sensors and cleaned and rotated the Vanos solenoids as preventative maintenance, one of the solenoids did sound like it was moving freer than the other when I had cleaned them but you could still hear movement.
Click to expand...
Did the problem occur only after you'd done this?
 
enuff_zed said:
thecookie125 said:
Recently changed the CCV, one of the post cat O2 sensors and cleaned and rotated the Vanos solenoids as preventative maintenance, one of the solenoids did sound like it was moving freer than the other when I had cleaned them but you could still hear movement.
Click to expand...
Did the problem occur only after you'd done this?
Click to expand...

The solenoids where cleaned about 6 months ago and the CCV was changed 700 miles ago, this issue started within the last 200 miles.
 
It could be plugs or coils, although if that was the issue I would not expect the engine to pick up again after 5,000rpm under hard acceleration. I had this issue in my 3.0l N52 and it brought up no fault codes.

Which engine do you have?
 
AveZ4coop said:
It could be plugs or coils, although if that was the issue I would not expect the engine to pick up again after 5,000rpm under hard acceleration. I had this issue in my 3.0l N52 and it brought up no fault codes.

Which engine do you have?
Click to expand...

Sorry should have been clear it’s a 3.0 N52, was yours intermittent too? Some days it’s fine others it will do it every other time I accelerate hard, I only noticed it come back yesterday and that was when it had reached 6500 rpm so its revved all the way out at that point.
 
AveZ4coop said:
It could be plugs or coils, although if that was the issue I would not expect the engine to pick up again after 5,000rpm under hard acceleration. I had this issue in my 3.0l N52 and it brought up no fault codes.

Which engine do you have?
Click to expand...

Also just to be clear under that high rpm range the car drives perfectly fine.
 
Mine was intermittent too, sometimes it would not happen for a week or two, sometimes it would happen repeatedly. It gradually got worse, and eventually was happening almost every day. Managed to replace all the coils and plugs for under £200 and it has run well for the last two years. It seemed to occur most frequently when under hard acceleration.

Did you say your plugs are not very old, if so they probably aren't the cause? Might be worth buying a replacement coil pack and moving it from one plug to another to see if you can clear the problem and identify if this is the cause? If it is, I would replace the remaining coils as if one goes, the others are normally close behind.

I hope this helps?
 
AveZ4coop said:
Mine was intermittent too, sometimes it would not happen for a week or two, sometimes it would happen repeatedly. It gradually got worse, and eventually was happening almost every day. Managed to replace all the coils and plugs for under £200 and it has run well for the last two years. It seemed to occur most frequently when under hard acceleration.

Did you say your plugs are not very old, if so they probably aren't the cause? Might be worth buying a replacement coil pack and moving it from one plug to another to see if you can clear the problem and identify if this is the cause? If it is, I would replace the remaining coils as if one goes, the others are normally close behind.

I hope this helps?
Click to expand...

That makes sense, plugs are 4 years old but only about 7000 miles and the coils look original so will be getting ready for replacement, it doesn't feel like it's misfiring more like it's closing the throttle almost.
 
You must log in or register to reply here.
Back
Top Bottom