Hi all, hoping to tap the collective wisdom of the forum to see whether I'm going to spend a little or a lotta money to fix my coupe.
Car specifics:
- 3.0si coupe, late 2006 (N52 w/ plastic VC)
- manual
- 163k miles
Symptoms:
- rough idle, not crazy but fluctuates between 680 and 720rpm. Car doesn't stall while idling.
- fluctuations in MAF reading at idle. Wavers between 4.5g/s and 3g/s. Very light pressure on the accelerator causes the MAF reading to immediately drop and stabilise around 3g/s
- weird jerky acceleration ONLY after an extended period on cruise control at motorway speeds.
- feels a little weak below 1500rpm
- revs drop sharply lifting off so gear changes can be a bit lumpy particularly at low speed/revs
- intermittent codes for lots of random stuff - MAF signal, O2 sensors, seat heating under voltage, window anti trap, parking sensors voltage, disa valve self diagnosis, throttle valve, and then today eccentric shaft sensor guide, reference, and plausibility.
Stuff I did already:
- replaced VVT gasket as there was the typical leak and I suspected possible vacuum leak. Maybe improved things a tiny tiny bit, could be placebo. Did the VVT relearn multiple times, sounds normal and works each time
- replaced all 6 Delphi coils with a set of Bosch coils that came with the car. No idea the age of either but car is the same with both sets.
- used contact cleaner on MAF and ESS connections - no difference
- replaced oil filler cap as it had a small leak - no difference
- new air filter and oil change including Mann filter + new o-rings on the cage and cap (wasn't expecting a difference)
I have a launch creader elite scanner which can do quite a lot in terms of reading data and various service functions like relearning VVT etc.
My thoughts:
- ESS definitely suspicious because of the symptoms and code. Especially because my fists of ham meant I snapped off one of the little clip things on the top of the socket - maybe the connection is not great.
- BUT could it be the battery just starting to give up?? The plethora of random other codes, especially the voltage related ones is interesting. It reminds me of when I had an R52 mini with a dying battery. It would start every time no problem but had loads of weird electrical issues and errors that went away with a new battery.
Forgive the long post, but hoping someone might take the time to read and point me towards the right things to look at to identify what needs fixing. Car seems pretty much ok aside from the issues above. Fuel economy is fine, engine is smooth and pulls hard above 1500rpm, no lights on the dash currently etc.
Thanks hugely in advance!
Car specifics:
- 3.0si coupe, late 2006 (N52 w/ plastic VC)
- manual
- 163k miles
Symptoms:
- rough idle, not crazy but fluctuates between 680 and 720rpm. Car doesn't stall while idling.
- fluctuations in MAF reading at idle. Wavers between 4.5g/s and 3g/s. Very light pressure on the accelerator causes the MAF reading to immediately drop and stabilise around 3g/s
- weird jerky acceleration ONLY after an extended period on cruise control at motorway speeds.
- feels a little weak below 1500rpm
- revs drop sharply lifting off so gear changes can be a bit lumpy particularly at low speed/revs
- intermittent codes for lots of random stuff - MAF signal, O2 sensors, seat heating under voltage, window anti trap, parking sensors voltage, disa valve self diagnosis, throttle valve, and then today eccentric shaft sensor guide, reference, and plausibility.
Stuff I did already:
- replaced VVT gasket as there was the typical leak and I suspected possible vacuum leak. Maybe improved things a tiny tiny bit, could be placebo. Did the VVT relearn multiple times, sounds normal and works each time
- replaced all 6 Delphi coils with a set of Bosch coils that came with the car. No idea the age of either but car is the same with both sets.
- used contact cleaner on MAF and ESS connections - no difference
- replaced oil filler cap as it had a small leak - no difference
- new air filter and oil change including Mann filter + new o-rings on the cage and cap (wasn't expecting a difference)
I have a launch creader elite scanner which can do quite a lot in terms of reading data and various service functions like relearning VVT etc.
My thoughts:
- ESS definitely suspicious because of the symptoms and code. Especially because my fists of ham meant I snapped off one of the little clip things on the top of the socket - maybe the connection is not great.
- BUT could it be the battery just starting to give up?? The plethora of random other codes, especially the voltage related ones is interesting. It reminds me of when I had an R52 mini with a dying battery. It would start every time no problem but had loads of weird electrical issues and errors that went away with a new battery.
Forgive the long post, but hoping someone might take the time to read and point me towards the right things to look at to identify what needs fixing. Car seems pretty much ok aside from the issues above. Fuel economy is fine, engine is smooth and pulls hard above 1500rpm, no lights on the dash currently etc.
Thanks hugely in advance!
