ISV Cleaning

[Hutty 10]

My VR6 has a lumpy idle and random flat spots at low revs, especially when cold. I've got a long list of culprits but thought I'd start with cleaning the ISV. Having got under the bonnet I see the hose clamps are what look like single use Oetiker ones. Any idea how to get them off and is there any problem replacing them with screw type jubilee clips?

[fendervg 32]

The clips will come off when you compress the join with some flat nosed pliers. Standard jubilee are fine as replacements, and some carb cleaner will do the cleaning for you.

 

Unfortunately VR idle problems can be tricky to diagnose - you could also check:

- The ISV baffle box, you'll see it to the right of the ISV

- The vacuum lines from the brake servo, to the right of the inlet manifold and then below the air box from the throttle body to the PCV valve assembly

- The plastic intake boot between the air box and TB

[robrado974 1]

Bad weather has stopped play on my bad idle problems . Good luck with finding the culprit.

[Hutty 10]

Thanks for that. Sounds like people on the forum have also had some success by cleaning the MAF, so I'll be spraying electrical contact cleaner on the MAF if I don't cure the issue with the ISV work.

[fendervg 32]

If it's an early MAF it's supposed to be self-cleaning (the element should burn off any contamination) so it's generally not recommended to clean them that way as they are very expensive to replace - best to test by swapping in a known good one if you can find one.

[robrado974 1]

Fendervg is correct about the MAF . It wouldn’t hurt to spray contact cleaner on the plug though. Finding the idle problem can be difficult. you could find a split in a vac hose and you are on to a winner . I’ve been trying to solve mine for a while now.

[_Matt_ 32]

What sort of idle symptons are people seeing - mine hunts (can't see on the tacho but can feel it in the cabin). VAG-COM live readings say it idles between 640-680RPM. Sort of every second or two it drops 40RPM and recovers.

 

When driving it seems to sort itself out and I don't notice flat spots.

 

I shall check out the 3 things mentioned in fendervg post (ISV, vac leaks and the airbox to TB plastic). Is carb cleaner OKAY to spray around vac hoses when searching for leaks?

 

Edit to add - just went out and inspected - my black suitcase damper box thing attached to ISV makes a bit of racket - in fact when I put my hand over it I can feel air at the seems. Need it get it off an inspect. Maybe this is of some use to other hunting idle issues. Part number: 021 133 429 A

 

Cheers

Matt

Edited December 7, 2018 by pfnsht

[Hutty 10]

Sounds like your ISV silencer box. I know the guys in the USA on the VR6 Vortex forum are quite keen on removing it. There are quite a few videos on it under "ISV Delete". Personally I prefer to keep things standard but it's an option if you narrow it down to that cause.

[fendervg 32]

They are cheap enough to replace as they are also found on the 2.8 VR6 engines.

[robrado974 1]

Other than checking mine for splits, I haven’t really seen a problem with the damper box , but if they are cheap enough I will just replace it, it’s another thing crossed off the list.

[_Matt_ 32]

Where is the best place to buy the damper box? Everywhere I look is out of stock.

 

What’s the deal with getting rid of it?

Edited December 9, 2018 by pfnsht

[skid 1]

You can get specific MAF cleaner spray. I also spray a light lube into the ISV once I clean mine.

I replaced my Damper box from VAG this year.

Spray all the vacuum hoses with carb or brake cleaner and see if the revs rise, if the do you have a leak.

Even better get a local garage to smoke test the vacuum system if they have the right equipment.

[Hutty 10]

I just get my car running well and a backfire has shattered the muffler/silencer attached to the ISV! Can anyone tell me the part number of this component? Google searches are only coming up with the metal ISV on its own.

[_Matt_ 32]

Yeah I posted it on the last page - it’s 021 133 429 A but I’ve been unable find a new one on internet searches. Figure we need to contact VW parts or TPS

[fendervg 32]

Where are you looking on the web? A google for that part# throws up lots of results, first one is on fleabay:

https://www.google.com/search?client=firefox-b&ei=RHQVXPmELobmrgSF6aiQDQ&q=021133429A&oq=021133429A&gs_l=psy-ab.3...18818.22263..23780...0.0..0.104.298.2j1......0....1..gws-wiz.q_xQ6FTQi3w

[_Matt_ 32]

That’s weird, I’m doing the same and only see stuff from America (out of stock) and some vwparts international (out of stock too!)

 

There is one for sale for 69 quid from America on eBay. Hmm I might need to try another computer

[fendervg 32]

Try ebay.de as well - I think I paid about 40 for a genuine one - a lot considering it doesn't really do very much.