Viewing 19 posts - 1 through 19 (of 19 total)
  • VW Tdi Experts, your help please..
  • woody2000
    Full Member

    I have a 2007 B6 Passat 2.0TDI with ~67k on the clock which has developed what can only be described as a momentary stutter/hesitation at about 1800-2000rpm and is difficult to hold it at that speed due to the hesitation. Sometimes it’s worse/better but I can’t pin down any consistency. It clears as soon as you speed up and the car seems fine otherwise but it’s obviously a niggle. Fuel economy does seem to vary quite a bit and I’m wondering if that’s linked somehow.

    It’s well serviced, both by me and the previous 1 owner. So well serviced in fact I’ve had to get a new service record! No fault codes are logged (as far as I can tell – I have a cheap OBD scanner + app)

    It gets pretty regular motorway runs, but is mostly used for commuting and running about locally. It’s had a fuel system cleaner (Forte) put through it more than once, injectors were replaced in a recall at about 30k miles. No DPF on this car.

    Any thoughts STW before I take it to a local diesel specialist?

    molgrips
    Free Member

    I think that’s my car. I had a stutter when cold – it would cut in and out a bit at that speed but only when relatively cold. There was a recall on the injectors which I think may have been related. Talk to the dealer. EDIT ah I see that you have.

    I’ve done so much to the car that I honestly can’t remember if I did anything specific to fix it. There’s been reports of problems with the injector wiring – might’ve just wiggled that and sprayed it with WD40. It was ages ago anyway and it’s now gone.

    Sorry, not very helpful.

    craigxxl
    Free Member

    Could be as simply as the fuel filter that needs changing, also the EGR valve or a split boost pipe.

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    woody2000
    Full Member

    Cheers molgrips 🙂

    I wondered about the EGR valve Craig, is that easy enough to remove and check? Does a split boost pipe have any other symptoms?

    Fuel filter changed at every service I’ve had done (4), including the one done in the last couple of weeks.

    Suggsey
    Free Member

    Also check air mass meter although if that’s failed completely they normally go into limp mode but the hesitation is similar in a failing one.

    brassneck
    Full Member

    Sounds just like the issue I had with my S Max (well, one of many) – fuel filter replacement cleared that up.
    Check they did it – mine actually hadn’t been once, hence it took a while to find!

    Coincidentally its final issue before I binned it was a split boost pipe – this was very obvious though, it went into ‘limp’ mode and had engine management lights on.

    danradyr1
    Free Member

    Sounds like my van 6 months ago, 07 transporter with 160k on the clock. They took ages to find the fault but eventually found it was the EGR valve and an earthing fault. Anyway, all up it was about £1k.

    Just checked, cost was £610.

    joshvegas
    Free Member

    split boost pipe.

    It wouldn’t get better with speed though just smokier and smokier.

    That’s my experience of my tdi

    craigxxl
    Free Member

    Split in the boost pipe can cause flutter as the turbo spins up to peak. As Josh said normally accompanied with dark exhaust emissions.
    EGR Valve can be cleaned without removal via removing the pipe at on side and spraying the internals with something like Mr Muscle, however I would remove and clean properly. EGR failing feels like a dead spot in the rev range that suddenly clears.
    If the fuel filter hasn’t been replaced within the last 20k miles then replace that first to rule it out before worrying about any of the other possible causes.

    molgrips
    Free Member

    I’d expect codes if the EGR was failing though. I think it’s quite well instrumented…?

    woody2000
    Full Member

    I’m pretty happy the fuel filter will have been changed, I take the car to a local garage that is owned and run by some biking buddies of mine. I trust them to have done what they’ve said they’ve done. However, no harm in checking I guess!

    unovolo
    Free Member

    Had a similar issue on my Renault Modus always at around the 2k Rev mark, didnt seem to matter what gear.

    Turned out to be the contact track/Potentiometer thingy inside the fly by wire throttle pedal being dirty or worn.

    One quick replacement part later(£15 off ebay) and it was fixed.

    jimbobo
    Free Member

    Is it a bkd (140) engine? Egr is at the front, easy enough to remove and have a good look at, it’ll be pretty gummed up even if it’s not the problem, the Cost of removing and cleaning is minimal (brake cleaner shifts it)

    Sundayjumper
    Full Member

    Our old car (2006 B6 Passat 2.0TDI) went through a phase of stuttering & going limp. Fault codes pointed first to MAP & then to MAF, but replacing them made no difference.

    It turned out to be a slightly iffy earth near the n/s headlight. There’s a couple of wires bolted down to an earth point. Undo, wire brush, tightened back up and we had no more issues. Got to be worth a try, it’s easy and free !

    molgrips
    Free Member

    Yeah I’ve had a few iffy earth connections too. Right hand side of the engine, remove air box, battery, and the ducting for the wiring you should see two obvious earth points and one right at the back you can only just reach, by the ABS module.

    woody2000
    Full Member

    Cheers chaps, few things to at least check 🙂

    benjamins11
    Free Member

    Is it a bkd (140) engine? Egr is at the front, easy enough to remove and have a good look at, it’ll be pretty gummed up even if it’s not the problem, the Cost of removing and cleaning is minimal (brake cleaner shifts it)

    The throttle body and egr actuator valve is at the front, the egr cooler is on the back.

    I had similar symptoms to this on my bkd, I went through all this stuff – taking the throttle body off and cleaning , checking the egr turned out it was a sooted up turbo – vw 2.0 tdis have a variable vane turbo that gets gummed up – causes the car to run too much boost.

    Try reving the nuts off it in third up a hill and see if it overboosts? i.e goes into limp mode because of the overboost condition. A recon turbo is about 400. Not too hard to fit if you have the time.

    Sundayjumper
    Full Member

    Funny thing with the earths was that they didn’t *look* dodgy in the slightest. Some of the electronics must be very sensitive.

    molgrips
    Free Member

    Gummed up turbo vanes shouldn’t need a new turbo surely?

    Some of the electronics must be very sensitive.

    Aye – the one near the ABS seems to be the one that grounds the map/boost sensor. I was getting readings slightly out which threw an implasuble sensor code and also slightly affected shifting on the auto because there was slightly more power than it thought there was.

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