Rough idle

[JimmyH]

Was wondering if anyone has had similar problem to this. I searched and didnt find anything too similar. My car is an 08 Jetta 2.0TFSI DSG.

Over the past few days ive noticed that whenever I pull up to a stop light the car will idle quite rough and sound like its about to die. I also feel like its been holding gears for too long when slowing down sometimes. Tonight while driving home from work I noticed the rough idle more than usual. When I got home I parked it in the garage and turned it off and then back on, and after starting the idle is rough for a few seconds then flattens out back to normal. But if I rev the car, once the revs come back down, it once again idles rough for a few seconds like its about to die then flattens out.

Not sure if its related but my housemate noticed that when I turn the car off, it sounds like theres a slight hissing coming from the engine for about 5 seconds straight after (not the normal wind down whine, it sounds like air leaking or something?)

I have the car booked in on wednesday morning to get looked at but thought id check here to see if anyone could shed some light on the matter!

Cheers!

[Umai Naa!!]

Sounds like it could possibly be the PCV, which is fairly common.

[JimmyH]

I saw someone mention that in another thread. Should I pull out the dipstick to check if its sucking air? What does a problem with the PCV entail? Thanks for your help!

[JimmyH]

Ok from what I can see looking it up on the net it sounds exactly like a PCV issue. It is sucking air when I pull out the dipstick. I hope it is an easy fix! However this is just another problem on the list of things that have happened to my car, and its making me contemplate selling it unfortunately.

[vdubmotorworx]

manifold pressure valve for sure... if you have it at idle and try to remove the oil filler cap it won't move because of the pressure, turn the engine off and it will release easy, when its popped you get the hissing and I've also heard the flywheel screem !.Think the valve is 200-300 bucks or so, 20 mins fit if you can get the engine cover off, that's the only hard part especially if you have not removed one before.....VDUB...

[h100vw]

manifold pressure valve for sure... if you have it at idle and try to remove the oil filler cap it won't move because of the pressure, turn the engine off and it will release easy, when its popped you get the hissing and I've also heard the flywheel screem !.Think the valve is 200-300 bucks or so, 20 mins fit if you can get the engine cover off, that's the only hard part especially if you have not removed one before.....VDUB...

Audi Volkswagen Manifold Pressure Vacuum Check Valve 07C133529A NEW VW | eBay

This thing or something similar?

Gavin

[vdubmotorworx]

no not that... hard to explain. .. but its held on with 4 torq screws. has 2 clip push on pipes and a flat dome on top..also has a red rubber gasket that i would reuse as they are 50 bucks for the gasket!

[Fixxxer]

Its the PCV, mine just died a few weeks ago. Once the engine was warm, mine would whistle all the time.
Pull the dipstick out a little and the whistle would stop. Mine didn't have any bad idle problems, but felt sluggish.

Replaced with Golf R PCV, revision N.

Mine is a 2008 Golf GTi, so I gather yours is same engine (BWA).
Should be around $90-100 from VW parts, or u can buy off the US sites for less.
Easy to replace if you know what your doing, 20mins.

Fixxxer

[Umai Naa!!]

The item that's highlighted.

[The One]

It's called a pressure relief valve, just tell them it's connects to the front side of the rocker cover, they will know exactly what it is considering they quote them up on a day to day basis.

[JimmyH]

Thanks for all the info guys! Im not the most mechanically minded person, so I wouldnt have a clue how to change it, but ill see what VW says when I leave them my car and if they quote me something ridiculous, I might consider trying haha

[Splashalot]

JimmyH, did you get this issue resolved? My 2007 GTI is exhibiting exactly the same symptoms.

[JimmyH]

Sure did! It was the PCV as most people said =)

[Splashalot]

Cheers

This is good info - means I can go into the dealer informed.

[Rxticle]

Yep. Had mine replaced today.