Lumpy idle

[northyracing]

Right I see I will take the car to a local mot centre and see what they say. If I get a high reading what would cause this

[Saintsteve]

If your suffering with High hydrocarbons, means more then likely, you have gummed up inlet valves due to the nature of the engine and the way it recirculates its internal combustion. Because the car is direct injection, the fuel is injected directly into the cylinder , and not sucked in past the inlet valves which would normally wash them to an extent and stop carbon building up,thus causing poor air flow into the cylinder, especially cyl 4 as it gets the least amount of fresh air flow via the inlet manifold.resulting in poor idling..

This would constitute a possible misfire on a cylinder or (s) .vcds would possibly show this, where's your snap on tester may not.
It's well worth doing an emissions check,this will then rule out any mechanical issue causing your problem.

 

[northyracing]

That's shed a lot of light I will get an emissions test done backed up with a vcds reading and go from there at least I will know roughly what to do then. If it is the valves how would I fix this

[Saintsteve]

That's shed a lot of light I will get an emissions test done backed up with a vcds reading and go from there at least I will know roughly what to do then. If it is the valves how would I fix this

If by using intake valve cleaner doesn't do the trick,  ie a couple of cans,  followed by an Italian tune down the motorway doesn't help,  then it's inlet manifold off to access the valves and scrap off the carbon directly.
This problem is becoming more and more of an issue as these engines are starting to hit higher mileages.

[northyracing]

When you say valve cleaner where do you actually spray it into is it the intake where the PCV hose goes into and what's this Italian tune down you mean sorry if I sound dumb lol

[Craigh1983]

Atleast I no there are 3 of us in the same boat now it's actually doin my nut in now can't seem to fix it I have tried changing things but with no results such a shame really. Do either of you notice at low speeds ie around 20 to 30 mph it's feels hesitant when driving almost like not as smooth as they should be

I can't say its hesitant really but from some of the comments that Steve made it seems to tie in with what happened to my car. When I first bought it it was juddering really bad and I had a misfire on cylinder 3. Took it to the garage and it turned out to be a bad injector. Had it changed but he said there was a massive build up of carbon on the piston or valve (can't remember which he said) and he had to scrap it off and clean it. So it makes me wonder if all te other pistons have a build up of carbon and thats where im getting the slight judder from.

My car has actually done about 110000 miles so it could be the age of the car.

Does anyone know if it would be a big job to have it all taken to bits to have it cleaned?

[northyracing]

Lovely stuff so in theory the spray sort of softens the as you would say crap up and the the Italian way should burn it off I have got some wynnes carb and intake cleaner to hand or would you recommend proper egr cleaner in a way a tenner is nothing to lose really so happy days. If it solves my problem. Another thing I forgot to mention is mine only does it when car is warm on start up she don't miss a beat

[Saintsteve]

Lovely stuff so in theory the spray sort of softens the as you would say crap up and the the Italian way should burn it off I have got some wynnes carb and intake cleaner to hand or would you recommend proper egr cleaner in a way a tenner is nothing to lose really so happy days. If it solves my problem. Another thing I forgot to mention is mine only does it when car is warm on start up she don't miss a beat

If your car has done more then 50,000 miles, I would do the above if I'm honest. Only does good and as you say softens the carbon, and with a good blast will try and burn off some of the carbon. cheaper then a cylinder off and decoke 

Terraclean is worth doing the other side of things. I will be doing this yearly from now on. Doing lots of short journeys makes things worse when dealing with gummed up inlet valves.

It cured my idle missfire issues.

Emissions test 1st though will indicate whether you need to look at this ok?.

[northyracing]

I only really do short journeys too makes me now wonder if it was driving while PCV was naffed that might have helped cause this problem I will defiantly give it a try like you say can only do good. Will just get a few cans and see what I can do thanks for your advise fingers crossed will cure it

[northyracing]

Right I done the Italian tune up and sadly hasn't made no difference so another one off the list to try

[Saintsteve]

Right I done the Italian tune up and sadly hasn't made no difference so another one off the list to try

Italian tune up may work if you do the Terraclean and the EGR spray treatment...

By doing the high revs is not gonna cure it unless you've put something through the engine first  

Or have you done this in super quick time??

So what was the emissions test outcome????



Your not following the advise thats put in front of you..

[northyracing]

Sorry was mention to say I sprayed some carb and intake cleaner via the PCV port on intake manifold purely because I had a can spare just thought as there is nothing to lose and I was bored. Not as yet done emission as everywhere was busy today

[Saintsteve]

Sorry was mention to say I sprayed some carb and intake cleaner via the PCV port on intake manifold purely because I had a can spare just thought as there is nothing to lose and I was bored. Not as yet done emission as everywhere was busy today

If your hydrocarbons are low, then that will rule any carbon and mechanical issues out. Then VCDS will be your next purchase or give the car to a dealer to diagnose it properly.

[northyracing]

Above 3k it drives lovely do you reckon it could be something silly like the original map playing up as I had a hesitation in my mk4 r32 which turned out to be the standard vw map

[Saintsteve]

Above 3k it drives lovely do you reckon it could be something silly like the original map playing up as I had a hesitation in my mk4 r32 which turned out to be the standard vw map

Unlikely..