Mk V, 05 plate, Engine idle problem !

[Saint Steve]

Thank you, could you tell me a little bit more about the PCV valve ?? what is it, where is it etc ! thanks......

Its under the airbox, basically its a rubber diaphragm which helps keep the crankcase pressurized. If it splits, especially if your car is remapped, its known to split and vent via a tiny hole in the PCV housing into the engine bay, you would smell it in the cabin if it was leaking. I had to change mine with this very issue. I noticed a tiny hissing sound AFTER the ignition was shut off under the airbox. PCV was £29 from VW dealer.

What sort of smell would you get in the cabin?

Also, what affect would a dodgy PCV have on performance at road speeds? My car is sometimes lumpy on start up, but has never had a misfire or lumpy idle.

i didnt have issues with performance, only idle and start ups

[jaydubveedub]

@ Saint Steve - thanks for replies.

I've had the car a year now (it's done 55k miles) and in all the time i've had it, it's always had an intermittent issue of being a bit lumpy on start up, although only for a second. I changed the plugs but it made no differnce. I've never had issues with a lumpy idle.

I don't get an engine oil smell in the cabin, but I have noticed over the past few months that when the engine is warm (i.e. after a journey) there is a slight engine oil smell from the outside of the car, particuarly if I lift the bonnet. The engine bay appears to be dry, it doesn't leak on the driveway (or undertray) and oil consumption is normal. Could this be the PCV causing the smell? Perhaps early stages of failure?

Not sure if it's connected, but the cambelt was done recently.

All in all, the car drives A1 though.

[Saint Steve]

The Rubber diapragm on mine was leaking to the outside of the casing and had not actually torn. But i kept getting engine vapour smells into the cabin.

Its really easy to replace, hardest part if you havent before is removing the airbox. The valve is under £30 from vw, and if it hasnt blown, its worth also checking it cus it normally gunks up with congelled oil and sludge which does aid the engines breather system.

Mine had done 45k when i changed mine.

I helped someone else with simular issues and his was cured by this aswell..

http://www.mk5golfgti.co.uk/forum/index.php/topic,15111.0.html

[flyingzard]

I get the exact same problem. Cold start is so lumpy that i have to give her some gas to get her going in the morning.

I don't get the idle problems though. It does idle ever so slightly high - a little over 1000 RPM. I also have not noticed any smells in the cabin.

Would you think this is a PCV related as well Steve?

Saw you on the road again the other day btw 

[johnford60]

Might starts up ok, little squeak, think its the Alternator belt.. But once warm, the idle is a little jumpy and all over place, not loads , but enough to hear the engine and exhaust note flutter.

Might just change my PCV valve anyway, probably clogged.

[Saint Steve]

^^squeek will be the cambelt tensioner johnford60 . Goes when warm, but sounds like a loose fanbelt when cold.

Since ive changed my Pcv shes fine on cold starts now, but mine always used to hate waking up in the morning, used to stuter and fart for a few seconds, and then it would settle, and thats just me, let alone the car


Where abouts flyingzard. Gota feeling i clocked you aswell, 58 plate black isnt it?

I remember thinking i saw you but dam if i can remember where it was

[johnford60]

Its only a 1/2 secound squeak sound? While engine is turning over

[flyingzard]

^^squeek will be the cambelt tensioner johnford60 . Goes when warm, but sounds like a loose fanbelt when cold.

Since ive changed my Pcv shes fine on cold starts now, but mine always used to hate waking up in the morning, used to stuter and fart for a few seconds, and then it would settle, and thats just me, let alone the car


Where abouts flyingzard. Gota feeling i clocked you aswell, 58 plate black isnt it?

I remember thinking i saw you but dam if i can remember where it was

Sholing end of Hinkler road. I did wave 

These PCV thingy's easy to fit - i aint no mechanic 

[Saint Steve]

easy peasy. Takes about 20 minutes all in

[winrya]

easy peasy. Takes about 20 minutes all in

Any guides around steve, mine is getting more shaky by the day.  I get the occasional smell of oil, its really shaky at 1200rpm when cold and a little bit shaky once warm.  Not noticed any performance losses or an increase in fuel consumption but I'm thinking this is worth changing especially as its just had a service and cambelt and waterpump change and its not changed at all