krishen 2 Posted January 22, 2011 Have a random cutting out issue (genrally when car is warm). So thought id try cleaing the isv. Is there a guide to taking it out and cleaning? Thanks Quote Share this post Link to post Share on other sites
AlgarveVR6 0 Posted January 22, 2011 very easy unplug wires and hoses spray inside with carb cleaner 2 or 3 times replace. job done, or mine was anyway :clap: Quote Share this post Link to post Share on other sites
fla 9 Posted January 22, 2011 Basically as Algarve says. But make sure you lube after cleaning with carb cleaner though. When you spary with carb cleaner, shake it around and drain the old mucky fluid. Quote Share this post Link to post Share on other sites
jimpy66 0 Posted January 22, 2011 Basically as Algarve says. But make sure you lube after cleaning with carb cleaner though. When you spary with carb cleaner, shake it around and drain the old mucky fluid. I found that the only way I could get it spotless was to dip some cotton buds in solvent and gently 'scrub' the valve clean. The little revolving cylinder had to be rotated by hand and held in the 'open' position so I could clean all the areas. The odd thing is that mine felt as if it was revolving freely without any of this, but once it was cleaned, the idling/cutting out was cured, so I have nothing else to attribute it to other than it must have been sticking a little. Quote Share this post Link to post Share on other sites
RW1 0 Posted January 22, 2011 The odd thing is that mine felt as if it was revolving freely without any of this, but once it was cleaned, the idling/cutting out was cured, so I have nothing else to attribute it to other than it must have been sticking a little. Yeah, you may have had what was happening with mine upto mid summer last year. Running rough at lower RPM and idle not sweet. Didn't clean the ISV. Instead "execised" it using VCDS output tests so it clunked rather loudly, ie. full aperture sweep open/close. Since doing that, the VR6 has run smoothly and like it should do. . Quote Share this post Link to post Share on other sites
fla 9 Posted January 22, 2011 RW1, i pulsed mine with a 12v supply a few times, dont know if this would have done the same as VAGCOM? Quote Share this post Link to post Share on other sites
awright182 0 Posted January 22, 2011 My idling is a bit up and down. Where is the ISV located? Quote Share this post Link to post Share on other sites
RW1 0 Posted January 22, 2011 My idling is a bit up and down. Where is the ISV located? Under the rear ignition lead carrier engine cover to the inboard side of the throttle body. Cover needs to be removed to access. RW1, i pulsed mine with a 12v supply a few times, dont know if this would have done the same as VAGCOM? Effectively yes. But with VCDS, you don't need to disassemble anything other than the gear shift cover panel in the centre console to plug into the diagnostics socket. . Quote Share this post Link to post Share on other sites
jimpy66 0 Posted January 23, 2011 My idling is a bit up and down. Where is the ISV located? Under the rear ignition lead carrier engine cover to the inboard side of the throttle body. Cover needs to be removed to access. RW1, i pulsed mine with a 12v supply a few times, dont know if this would have done the same as VAGCOM? Effectively yes. But with VCDS, you don't need to disassemble anything other than the gear shift cover panel in the centre console to plug into the diagnostics socket. . If dirt and deposits are old and hard (bearing in mind that air from the crankcase breather goes through this) 'exercising' it will give only a temp fix- only a thorough clean will exclude this problem Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted January 23, 2011 Does VCDS step through PWMs? What you need to do is observe what the valve does at various openings. The valve is just a thin blade (~ 10mm) that moves across the apeture visible in the outlet elbow. Full sweep tests don't tell you much but when fully open, have a look inside for any chunks of foam. This comes from the damper box as the oily, hot fumes break it down over the years. My valve was OK at full sweep but would occasionally stick at 50% PWM because of a big chunk of foam stuck in there!! Quote Share this post Link to post Share on other sites
RW1 0 Posted January 23, 2011 A really dirty ISV you do have to clean but the check in VCDS Output Tests does two things. 1) The ISV is working. 2) Confirms the ISV is sticking if the exercising stops poor running. If it fixes temporarily, then you know the ISV is in need of thorough clean soon. 3) The test positively exercises the ISV shutter valve over its full travel, which the ECU while running the engine will not necessarily do. It's making sure the valve shutter will travell through its full sweep. It doesn't step through the PWM. Its the same as applying full voltage to it like Fla was doing by hand with a battery in the above post. Output Test does the same with the injectors, carbon canister valve and other valves if fitted. . Quote Share this post Link to post Share on other sites
fla 9 Posted January 23, 2011 thats useful info. How do you operate it through VCDS? Quote Share this post Link to post Share on other sites
RW1 0 Posted January 23, 2011 thats useful info. How do you operate it through VCDS? Here's a link to VCDS Output Tests . Quote Share this post Link to post Share on other sites
krishen 2 Posted January 23, 2011 My idling is a bit up and down. Where is the ISV located? Under the rear ignition lead carrier engine cover to the inboard side of the throttle body. Cover needs to be removed to access. . So is it easy to remove? I assume just a couple of nuts/botls to undo? I plan on taking it out completely and giving it a proper clean. Quote Share this post Link to post Share on other sites
fla 9 Posted January 23, 2011 very easy - remove the rear ignition lead carrier, you'll see it undreneath, looks like a small coke can. One connector on the base and two pipes with jubilee clips on them. Loosen the jubilees and gently ease the pipes off. Then slide the isv out of the rubber 'band'. Dont be tempted to force the flap open with a screwdriver from the small gap, it actually goes the other way! Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted January 24, 2011 3) The test positively exercises the ISV shutter valve over its full travel, which the ECU while running the engine will not necessarily do. It's making sure the valve shutter will travell through its full sweep. You'd be surprised. The valve will see openings of 100% to 27% during normal cold running and driving. It opens very early (3040rpm) on the overrun and stays open until 16-17 degrees is seen on the throttle angle. 27% is practically closed. Well, as closed as closed can be. VW leave a small gap in the valve at rest as a failsafe. The clunk you hear on full sweep tests is the valve hitting the stop. The stop can be adjusted with an allen key once you've picked out the sealing resin. "Excercising" is a curious description imo :D It's not a muscle that has atrophic, it's a simple PWM motor which either works and does what it's supposed to do, or does not. Quote Share this post Link to post Share on other sites
awright182 0 Posted January 24, 2011 Cheers on the info about location. A job for the weekend I think. Andy Quote Share this post Link to post Share on other sites
jimbobcornwall 10 Posted March 3, 2013 hi sorry to revive an old thread but the link no longer works to show how to do the vcds output tests , anyone know how to do this at all Quote Share this post Link to post Share on other sites
GusPW 0 Posted March 4, 2013 Can't help with the link I'm afraid, just bumping it up as I'm also interested in whether the un-licenced vcds will do the output tests? Quote Share this post Link to post Share on other sites
