Over-revving when changing gear

If it is holding revs, try cleaning the MAF sensor in the air filter box.

T5 TDI wrote: As you mentioned it is possible that the turbo is causing the problem by leaking oil into the intake under hard acceleration.  The engine then runs on this oil.  You ought to get it checked soon because if it gets worse it could lead to the engine being wrecked as it 'runs away' uncontrollably.  Do you see any smoke when accelerating?

Hi all, thanks for the replies. You know my gut feeling says the turbo is starting to play up, but I love the idea of simply cleaning the MAF sensor and all being sorted. Take it this is something pretty simple to do?

ANyhow, this morning when started from cold and I began my drive away (always carefully) a very subtle but new air rushing noise can be heard (guessing from turbo but could be anything). I guess its the turbo 'deciding' whether to fully kick in, but doesn't seem right. Once engine is warmed this is no more. Driving the van normally this morning the revs being held did not reoccur, but applying slightly more effort will surely cause it to repeat. Worried. I really need someone who knows what they are doing to honestly have a look at it. I'm concerned that if I take it to a VW dealer then they will simply quote for a v. expensive new turbo, when frankly it could be anything. I need someone/ an indy garage/ ore trustworthy dealer who really knows their stuff and will give me geniune advice rather than perhaps stating whatever they wish as I fear a main dealer would. We're based just south of Sheffield and close to Cehsterfield also.  Any recommended places?

Oh yes, no I've not noticed any smoke under acceleration. Before the last serive there was certainly alot of black smoke/soot being coughed out under acceleration, but since the turbo pipe was replaced this is no longer evident. Other thoughts, are that there may be a very minor amount of coolant loss, however, this could have been due to the service guys refilling to only just above the level that causes the sensor to say low level on thje dash. I've topped this up but have an inkling it may come on again after a few weeks.

Something else I curious about is what sort of power speed etc. that is to be expected from this pre DPF 2.5 130 engine. It has the standard 16in steel wheels and tyres. Now on the motorway I seem to have transporters with the smaller engine (just the red i in Tdi) thrashing it passed me. Now I'm not up for ragging my van around, but having seen youtube footage of T5's with the 130 engine toppping out at close to 120mph (on speedo), this is something I could only dream of ever managing. Not that I'd want to, but we seem to struggle to maintain 85mph. This is not a speed I'm keen to do often but it serves as an illustration as to what our van seems able to do. Can anyone perhaps indicate what they'd expect a regular serviced and problem free 2.5 130 to be able to manage without too many dramas. This will hopefully let me know whether ours really is struggling for power..

Cheers again  everyone...

My van had the problem of being very slow and over revving as you have described. I did 2 things, one was clean the MAF sensor, a real easy job to do, just get some carb cleaner onto the sensor, clean it all up and then leave the battery disconnected over night to clear the fault (you can do it with VAG-com if you have it). This certainly helped with the over revving and the speed. However, I also had a cracked turbo casing and I can't remember if this was a long time after or not. Go with the cheap option first!

Right, perhaps I'm looking at a dirty MAF as well as a tottering turbo. Or perhaps the MAF could also effect the turbo performance? One thing for sure is that my power is down. Guess that'd good and bad news! I'm off to see if I can find the MAF...

Kitawagon wrote: I'm off to see if I can find the MAF...

There's one available on fleabay....., should give you an idea of what you're looking for.

Edited by fantasam - 18 Sep 10 at 15:31

Hi all again. Sorry for late reply, only I had to walk home! All will be explained....

To answer your replies:

Fantasam. The van has just done 62,000 since late 2004. We also had a new water pump fitted (as we told there was a leak) so the coolant was flushed/refilled etc. You know the van felt great straight after the service and had the kind of oomph you'd expect (and you have), but this so rapidly went unfortunately. It was clear before the service that the turbo setup was leaking pressure in a big way (presumably from the pipe as we were told) due to the very loud hissing. However, the noises coming now are still the faint flutter just prior to 2000rpm at all times of use and the faint perhaps air leakage/stop starting sounds I described only with a cold engine. With reagrds to the MAF (many thanks for the link ), I found it, removed it and had a good look, all the plastics and housing seemed super clean to me but it is not really possible to see the metal. I was on my way to the garage to buy some carb cleaner/rubbing alcohol to do a clean when..........BOOM CRUNCH CRUCH GRIND ARGRHHH!

To T5TDI, if I propped up the bonnet and revved the engine, would the turbo kick in? Or does the turbo kick in under load (i.e. in gear and driving). If so then I think that's what I should have done and wiggled the pipes as you rightly suggested to see if any leak. Unfortunately I am unsure as to where the turbo/intercooler and pipework is !

Anyhow all this is a little imaterial as whilst I headed to the garage and attempted to pull out from a side road on to a busy A road, boom and crunch, suddenly no driving force and instead a horrible crunching and grinding no matter what gear I chose. So a big problem, there's me covering both lanes, stuck. Jump out fortunately get both flows of traffic to stop without incident, someone manages to help push me back onto the side road and both a sigh of relief and swearing can begin! Two hours later my dad has come to the rescue and helped two the fallen chariot back to the drive. Desparate! Now surely this is a total coincidence? My other half is not convinced I haven't managed to reck our pride and joy by fiddliong with the MAF! HAh, you have to laugh, but really what a terrible coincidence I explained . Nope she's not best pleaed.

So what could this latest more catastophic problem be? Clutch, Flywheel, Gearbox, driveshaft???? Who knows! The grinding seems to be coming from the front left mostly, but I'm not seeing sny drive from either wheel. Engine ignition and revving out of gear seems normal. Ivf engine of and placed in 5th gear, the van can be rolled backwards, no resistance, but the front left wheel does seem to click or hit a lsight notch every quarter turn....?? I did mention a new judder when the engine was cold and pulling away in 1st gear over the last couple of weeks, could this be related? Is it possible that the drive shaft (if thats the right term) to one of the front wheels has gone or does this sound more like a catastrophic gearbox or clutch failure?

Sorry to drift this lack of power issue in to a total T5 meltdown! Hopefully this story will end happily, but as it stands I'm now not just keen to find a really decent VW mechanic near to Sheffield, but am in dire need!

Anyone with any further pointers on all this, your advice is really really appreciated. I'll endeavour to keep you posted on any developments and diagnostics etc. when I get it to a garage..

Cheers

Kitawagon..

Hi, the grinding noises only come when in gear with the engine running and foot off the clutch..

Right, bugger, thought as much, rubbish... Thanks for your quick input! At least something like this can be fixed, albeit at a high cost no doubt, however, when I get it back it'll still be lame in the power turbo stakes. Pants. Perhaps it's possible to get the turbo system pressure tested also when in the shop and all can end on a much lighter note (wallet included).

Kitawagon out......for now

Final thought....for all those with problematic T5's would you buy another? I'm starting to feel like never again and that is really gutting as I love it to bits (literally) in many ways, but really such unreliability as covered in this forum is just mind boggling. Totally unacceptable and shocking. Shame. I can only imagine what it must be like to spend towards 40,000 on a California for example and then to have such troubles!

VW master-tech. Thanks for your thoughts, however, would this cause rev peaking at all times or just when the engine is having to accelerate hard?