Rough idle

[Mark_DF05]

Car has been running pretty rough lately and seems to be getting progressively worse. The idle is higher than normal on start up before settling down and fluctuates when sitting in traffic to the point where it almost feels like cutting out and can be real juddery when driving.

These symptoms first appeared a few months ago and I had the boost pressure sensor (MAP) replaced which seemed to fix the issue until now.

Scanned with a cheap code reader and got these:

P0322 Ignition/Distrubutor Engine Speed Input Circuit No Signal

P0322 Engine Speed Sensor (G28) No Signal

I assume the engine speed sensor needs to be replaced, anyone else had similar issues or replaced it?

EDIT: Definitely not the engine speed sensor at fault.

[pudding]

If the crank sensor really is bad, the engine won't rev past 3000-3500rpm.

Clear the codes and see if they come back. Could be historical codes that weren't cleared.  If they come back, it probably is the sensor if the above test is also confirmed.

The sensor is expensive (£130ish from VW) and a pain in the hoop to change as it's buried behind the oil filter housing gubbins.

I've got a spare one off my car that was misdiagnosed as faulty, but is fine, which you can have for £30 if needed.  I fitted a new one anyway as I ordered it in, and you can't return special order parts.

[Mark_DF05]

Ah cheers. I reset the code at the weekend so will see how it goes this week and scan it again. Certainly revs past 3500rpm so must be something else as you say.

 

[Mark_DF05]

Looks like I was barking up the wrong tree with this. Code hasn’t returned, must have been an old one. Still having the same problems so I replaced the PCV with a rev R one, hasn’t solved the issue but was probably due to be replaced anyway. Whilst I was there I unplugged the MAF with the engine running and nothing happened, if anything it ran smoother. Am I correct in thinking that indicates that it’s faulty?

Before replacing it should I get it checked with vcds to confirm? I don’t have it but sure I could find someone local.

[muff1991]

Looks like I was barking up the wrong tree with this. Code hasn’t returned, must have been an old one. Still having the same problems so I replaced the PCV with a rev R one, hasn’t solved the issue but was probably due to be replaced anyway. Whilst I was there I unplugged the MAF with the engine running and nothing happened, if anything it ran smoother. Am I correct in thinking that indicates that it’s faulty?

Before replacing it should I get it checked with vcds to confirm? I don’t have it but sure I could find someone local.

A full scan with VCDS would be beneficial, but if you have unplugged the MAF and the car runs smoother then yes, this usually indicates a problem with the MAF. Its always best to buy a genuine MAF too.. and at the cost of them, it might be worth finding someone local to confirm with VCDS for a couple of beer tokens first before splashing out.

[Mark_DF05]

Great thanks, i'll try get it scanned before shelling out for a new one

[Mark_DF05]

Not had much luck finding someone local with vcds yet although I did manage to swap the MAF over with a working one which made no difference so can rule that out.

[titchy]

A genuine MAF is over a £100 from VW so worth getting it checked I got a brand new one as mine was   damaged. after I bought it I had to get an air box in  it was what looked like a new genuine MAF and a new air filter. The air box had a split in it I contacted the seller he refunded me in full and told me to keep it I fixed it so got a bargain