engine management light on. car stutter between 1 & 3000 rpm

[mk5 polo]

Hey people

Looking for some info on this fault and hopefully how to sort it.

Recently the engine management light has come on and the car will but not always splutter and choke between 1000 & 3000 rpm and after that it revs fine in every gear.

The light can sometimes go off or come on. can start the car one day and it will be off but fault remains.

the splutter varies in ferocity.

Any ideas???

Thanks

[Tim_GTi]

I'd first try and give the throttle body a good clean out. Get some 'carb cleaner' from halfords. for this.

Remove the air box
spray some carb cleaner onto a rag and clean the throttle body and butterfly valve.
start the car and get someone to rev the car up and down continuely so the valve opens
spray around a third of the can on anf off into the throttle body
leaving the car running take it for a good spin to burn off excess cleaner

[mk5 polo]

The fault lies with a engine breather pipe. the pipe comes from the bottom of the engine and goes to the air filter it has become squashed and has lost its shape and as a result the engine stutter. played around with it and got its shape back and it work as normal but soon went back to being squashed the same way if you where to extract air from a hose pipe.

solution buy a new pipe.

[alexperkins]

If its getting squashed, id think you have a pressure problem that is causing a vacuum in the pipe making it shrink. Sounds like a blockage in the oil return valve on the back of the block.

[mk5 polo]

Hey alexperkins

I fitted the new pipe and it has solved about 99% of the problem but there is sometimes a small stutter. Whats the oil return valve on the back of the block? how do I check this?

thanks

[alexperkins]

Basically it seperates the oil and the vapour to stop the oil being pumped into the throttle body...its not something that can be easily accessed unless you are up behind the back of the engine. I would leave it and see how it goes.