Hello my vrs has started to idle at 800 rpm over the last few days I'm sure its always been 900. Its jumping up and down by about 50 rpm constantly when idling. And I feel iv got to give it i little bit more throttle when moving of from a stand still or let the clutch up slower than normal. I also noticed if your round the back end of the car you can hear i faint pop/pfff noise from the exhaust every few seconds abit like a misfire. The car drives the same as it always has the problem is ONLY on idle.

 

Theirs no CEL light on so im not sure where to start.

 

The maf if only about a year old so im thinking idle control valve or something along them lines.

 

Anybody got any ideas where to start?

Welcome to wonderful world of VAG vacuum leaks  :clap:

You recon its a vacuum leak? If it is ill be happy lol where should i start hunting/looking/listening iv never looked it the vacuum side of thing so not got a clue.

I'd say the most common causes of poor idle on VRS's are split boost/vacuum pipes, coolant temp sensor failure. The fact that you state it's seems to have lost a bit of power would have me looking at the pipework aroud the inlet manifold, which is very prone to splitting.

Will have a look at that. The power loss is berly noticeable and only when setting off. If im rolling in first at a junction then foot down there is all the power there should be. Was messing about yesterday and the car was doing 0-60 in dead on 7 seconds. So obv no power loss (would have expected it to have lost a second or so being 11 years old) . Just feels as if it wants to stall when letting the clutch out. But only very very slightly.

Ross, take note that inspecting those small vacumn lines down the back or the engine is a fingertips job; you can not see them adequately to see if one has cracked unless it's actually broken off.

Thanks. Gona go out just now, now the wee one is asleep. My bro can make himself useful and listen out for her lol. Ill report back in an hour or so. Over and out.

Hello my vrs has started to idle at 800 rpm over the last few days I'm sure its always been 900. Its jumping up and down by about 50 rpm constantly when idling. And I feel iv got to give it i little bit more throttle when moving of from a stand still or let the clutch up slower than normal. I also noticed if your round the back end of the car you can hear i faint pop/pfff noise from the exhaust every few seconds abit like a misfire. The car drives the same as it always has the problem is ONLY on idle.

 

Theirs no CEL light on so im not sure where to start.

 

The maf if only about a year old so im thinking idle control valve or something along them lines.

 

Anybody got any ideas where to start?

 

My vrs has idled at 800 (once warm) since i've owned it(3yrs).Never thought there was a problem(until now).In fact on vag com it gives shows 700-820 under the rpm reading.

My idle can depend on what battery drains are in use e.g. heated rear window, air con, lights etc.

 

Seems to vary between 750 and 900. Never ever been an issue though.

Right im back checked all the pipes around the inlet. Took the plate off to see under it properly. The only one that has any damage is going from the underside of the inlet mani to somthing on the end of the fuel rail. Removed and checked it, it was just some chaffing in the material covering the pipe.

 

Where next?

Edited 13 August, 201312 yr by Ross SY

Clean the throttle body?

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Theres two pipes under the inlet manifold that are held together for neatness by a rubber sleeve. Check inside that rubber sleeve. Even cut it off to get a better look

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Right guys its fixed. You think i would be happy about this but im not. After i put all the bits back together i fired up the car just to check if having a fiddle knocked something and was now worse or better. Anyway fired her up and walked round the front were i could hear a puff puff puff type noise. Lent in for a listen and a look sounded like it was coming from the back of the head. As i lent in i also noticed that one of my coil packs was up no big deal as everyone on here knows they ride up from time to time. Went to push it down and it wouldnt go and if i put pressure on it. the engine would idle normaly. Anyone guess were im going with this. Switched the engine off got a spark plug socket and out came the plug not even 1/8 of a turn!! Now yous are thinking what an idiot. IT WASNT ME!!!! My car was serviced by a very reputable garage about 2 weeks ago oil, oil filter, plugs and fuel filter. They couldnt have.. no didnt tightened the spark plug as the washer hadn't compressed. It must have worked loose over the 2 weeks since they had it. Ill be calling into said garage tomorrow for some very strong word. anyway gave the plug a wee rub with a soft wire brush as it was all carboned up plopped it back in tightened it up no bother.

 

Does anybody on here check work that well known garages do to your cars? Right down to the simple stuff like changing spark plugs at service time.

Yes

Another thing to note is the engine will idle higher when the air-con compressor is running, its normally 800rpm when not running.

This is the excact same problem as I am having right now the puff puff noise everything must be the same