Lumpy idle

[northyracing]

I keep posting the same problem on here to try get an answer but so far no joy. So far what I have done is new DV new PCV 4 new coil packs and plugs to match them new cam follower cam belt change but still getting the lumpy idle. I then had it plugged in which showed no problems what so ever. MAF was working fine and recorded no misfires either ,is just on idle that's all once driving pulls like a train could the problem be inside the standard map

[Tortaruga]

I keep posting the same problem on here to try get an answer but so far no joy.

I've noticed that. 

I feel your pain, your head must be wrecked by now. Without any fault codes it'll have to be a mechanical search, check, etc.

Is your coolant ok...level wise? I read somewhere that low coolant can affect idling, not sure if it applies to these cars though.

If it was me at this stage I'd talk to a very good technician/mechanic and ask his/her advice. Someone with years of experience will know a thing or two to check.

Hope you get it sorted soon.

[Saintsteve]

Did you get a emissions check done?

[bacillus]

What mileage has the car done?

[northyracing]

I have not had an emission test as of yet but lambda sensors was checked and working fine, the bloke who was doing the checks for me has been a well known mechanic for years and it has baffled him aswell the car has done 65600 miles coolant levels are fine if anything a little too much in there just beating my head against the wall now that's why I maybe thought it could be in the standard vw software

[bacillus]

Cylinders compression and intake valves condition been checked?

[northyracing]

Cylinders compression and intake valves condition been checked?

No not yet as not sure on how to do that. The weird thing is it only happens when car is on idle soon as you give it abut of throttle it's gone

[richtung]

im not sure if a lumpy idle is the same as rough idle but on the mk4, giving the throttle body a clean sorted this? i guess it could be the same thing for you.

[camfollower]

Cylinders compression and intake valves condition been checked?

No not yet as not sure on how to do that. The weird thing is it only happens when car is on idle soon as you give it abut of throttle it's gone

There's a great how to knocking about for cleaning your valves... As you'd appreciate it's quite time consuming, here it is:
http://www.golfmkv.com/forums/showthread.php?t=140523

[GTI-Pirelli]

Something for you to try (maybe):

I have had a bit of what I can only describe as a bit of a stammer on idle. It felt like a bit of a missfire altough VAG-COM stated none. I have had an occasional fault flagged up on previous scans on the Throttle Body so today i thought I would try to clean it.

I bought some Carbaurettor/Injector cleaner from Halfrauds to try to clean it. My thought was to remove the Throttle body to clean it through, but that looked like a right PITA to get it off. So plan B was as per instructions, through the air intake (I originally didn't want to spray through the Turbo & Intercooler but easier than dissassembly).

I removed the connection from the airbox/MAF sensor and sprayed (pulsed) in there as my beautiful assistant held the revs around 2-3k. I also removed the PCV connection and sprayed in there as well (again pulsed). Beware, the engine does not like it if take the vacuum pipe off so don't do this for too long! If you overdo it, it will stall but will restart eventually.

The car now runs great. I don't know if it is a placebo effect but first impressions are that the car feels like it breathes better and the stammer appears to have gone at idle. My car has nearly reached 67k miles.

Just a thought. Oh and I originally wanted to do the above (CAMFOLLOWER) but there was snow forecast and this seemed to be an easier first step.

[Saintsteve]

Something for you to try (maybe):

I have had a bit of what I can only describe as a bit of a stammer on idle. It felt like a bit of a missfire altough VAG-COM stated none. I have had an occasional fault flagged up on previous scans on the Throttle Body so today i thought I would try to clean it.

I bought some Carbaurettor/Injector cleaner from Halfrauds to try to clean it. My thought was to remove the Throttle body to clean it through, but that looked like a right PITA to get it off. So plan B was as per instructions, through the air intake (I originally didn't want to spray through the Turbo & Intercooler but easier than dissassembly).

I removed the connection from the airbox/MAF sensor and sprayed (pulsed) in there as my beautiful assistant held the revs around 2-3k. I also removed the PCV connection and sprayed in there as well (again pulsed). Beware, the engine does not like it if take the vacuum pipe off so don't do this for too long! If you overdo it, it will stall but will restart eventually.

The car now runs great. I don't know if it is a placebo effect but first impressions are that the car feels like it breathes better and the stammer appears to have gone at idle. My car has nearly reached 67k miles.

Just a thought. Oh and I originally wanted to do the above (CAMFOLLOWER) but there was snow forecast and this seemed to be an easier first step.

This is exactly what I did with a can of Wynns EGR cleaner, and I can report, mines improved along with the Terraclean treatment I also did.

(From reply 8 on link below)

@northracing

Read my recent thread titled Terraclean.
http://www.mk5golfgti.co.uk/forum/index.php/topic,61952.0.html

[northyracing]

Something for you to try (maybe):

I have had a bit of what I can only describe as a bit of a stammer on idle. It felt like a bit of a missfire altough VAG-COM stated none. I have had an occasional fault flagged up on previous scans on the Throttle Body so today i thought I would try to clean it.

I bought some Carbaurettor/Injector cleaner from Halfrauds to try to clean it. My thought was to remove the Throttle body to clean it through, but that looked like a right PITA to get it off. So plan B was as per instructions, through the air intake (I originally didn't want to spray through the Turbo & Intercooler but easier than dissassembly).

I removed the connection from the airbox/MAF sensor and sprayed (pulsed) in there as my beautiful assistant held the revs around 2-3k. I also removed the PCV connection and sprayed in there as well (again pulsed). Beware, the engine does not like it if take the vacuum pipe off so don't do this for too long! If you overdo it, it will stall but will restart eventually.

The car now runs great. I don't know if it is a placebo effect but first impressions are that the car feels like it breathes better and the stammer appears to have gone at idle. My car has nearly reached 67k miles.

Just a thought. Oh and I originally wanted to do the above (CAMFOLLOWER) but there was snow forecast and this seemed to be an easier first step.

Mine is the same it feels like a misfire but when plugged in doesn't register as a misfire so it almost feels like on idle someone on the outside of car slightly rocks the car but like I say ever so slightly so maybe could be a dirty throttle body it seems strange it's only happened after I had the coil packs fail

[northyracing]

I got some carb cleaner today and had the car revving at about 2500rpm and sprayed into the intake manifold via where the PCV plugs in and also inti the intake from the MAF to the turbo but still the problem is there so I am defiantly confused.com now

[northyracing]

Could the timing cause a lumpy idle as I had the cam belt done about a 1000 miles ago and seems after I had this done also coils plugs DV and PCV done I had this problem I didn't have it befor all of this done

[Saintsteve]

If the car is one tooth on the timing side of things out , then it would be down on power. perhaps log the MAF to see what the power is doing?

These cars idle quality isn't its strong point. Have you tried comparing it to someone else's Mk5 GTi?