The Brick-yard Homepage Brickwerks
Forum Home Forum Home > T5 Section > T5 Chat
  New Posts New Posts RSS Feed - Over-revving when changing gear
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Over-revving when changing gear

 Post Reply Post Reply Page  <123>
Author
Message
VW master-tech View Drop Down
Yardie
Yardie
Avatar

Joined: 28 Aug 09
Location: bedfordshire
Status: Offline
Points: 407
Post Options Post Options   Thanks (0) Thanks(0)   Quote VW master-tech Quote  Post ReplyReply Direct Link To This Post Posted: 19 Sep 10 at 00:13
would cause it at all times however would be alot more noticeable during hard acceleration as you described like the clutch slipping would give the disconnect route a go costs nothing to check and rules something else out
Back to Top
energysolutions View Drop Down
Vanorak
Vanorak
Avatar

Joined: 02 Dec 08
Location: Earth (For Now)
Status: Offline
Points: 3684
Post Options Post Options   Thanks (0) Thanks(0)   Quote energysolutions Quote  Post ReplyReply Direct Link To This Post Posted: 19 Sep 10 at 00:15
Originally posted by VW master-tech VW master-tech wrote:

would cause it at all times however would be alot more noticeable during hard acceleration as you described like the clutch slipping would give the disconnect route a go costs nothing to check and rules something else out
 
Good adviceClap
 
 
!!Never Eat Yellow Snow!!
Back to Top
VW master-tech View Drop Down
Yardie
Yardie
Avatar

Joined: 28 Aug 09
Location: bedfordshire
Status: Offline
Points: 407
Post Options Post Options   Thanks (0) Thanks(0)   Quote VW master-tech Quote  Post ReplyReply Direct Link To This Post Posted: 19 Sep 10 at 00:16
Thanks energy not all us at a dealer are there to pull your pants down!!LOL
Back to Top
Kitawagon View Drop Down
Groupie
Groupie
Avatar

Joined: 26 Jun 10
Location: Bath
Status: Offline
Points: 168
Post Options Post Options   Thanks (0) Thanks(0)   Quote Kitawagon Quote  Post ReplyReply Direct Link To This Post Posted: 19 Sep 10 at 00:20
Hah! A dealer, so I should choose my words carefully! Would you're average punter know where the clutch switch is or is it a Haines job etc...
Back to Top
VW master-tech View Drop Down
Yardie
Yardie
Avatar

Joined: 28 Aug 09
Location: bedfordshire
Status: Offline
Points: 407
Post Options Post Options   Thanks (0) Thanks(0)   Quote VW master-tech Quote  Post ReplyReply Direct Link To This Post Posted: 19 Sep 10 at 00:22
Kita you will need to disconnect the switch as i cant off hand remember which way the switch works open/off or open circuit/on try running the van with it disconnected if the fault still occurs take a piece of wire and join the 2 wires in the plug and try again if it sorts your fault then a new switch awaits easy to change just untwists and pops out
Back to Top
energysolutions View Drop Down
Vanorak
Vanorak
Avatar

Joined: 02 Dec 08
Location: Earth (For Now)
Status: Offline
Points: 3684
Post Options Post Options   Thanks (0) Thanks(0)   Quote energysolutions Quote  Post ReplyReply Direct Link To This Post Posted: 19 Sep 10 at 00:24
Originally posted by VW master-tech VW master-tech wrote:

Thanks energy not all us at a dealer are there to pull your pants down!!LOL
 
In my opinion the guys "out back" with a spanner in their hand usually arent, its the suave, economical with the truth suits "out front" who wouldnt know the difference between a cam shaft and a calm day that like to try out the Dick Turpin routine 
 
 
!!Never Eat Yellow Snow!!
Back to Top
VW master-tech View Drop Down
Yardie
Yardie
Avatar

Joined: 28 Aug 09
Location: bedfordshire
Status: Offline
Points: 407
Post Options Post Options   Thanks (0) Thanks(0)   Quote VW master-tech Quote  Post ReplyReply Direct Link To This Post Posted: 19 Sep 10 at 00:25
switch under the dash top of the clutch pedal pedal mounts in the bracket, yes i work in a dealer but am on here to help people out and learn some things myself this site is a great source of info and has a wide range of knowledge we could all do with a little help sometimes
Back to Top
energysolutions View Drop Down
Vanorak
Vanorak
Avatar

Joined: 02 Dec 08
Location: Earth (For Now)
Status: Offline
Points: 3684
Post Options Post Options   Thanks (0) Thanks(0)   Quote energysolutions Quote  Post ReplyReply Direct Link To This Post Posted: 19 Sep 10 at 00:27
Master can the switches operation be viewed on VAG COM/VCDS?
!!Never Eat Yellow Snow!!
Back to Top
VW master-tech View Drop Down
Yardie
Yardie
Avatar

Joined: 28 Aug 09
Location: bedfordshire
Status: Offline
Points: 407
Post Options Post Options   Thanks (0) Thanks(0)   Quote VW master-tech Quote  Post ReplyReply Direct Link To This Post Posted: 19 Sep 10 at 00:30
not sure with vag com on the vw system there are a number of 0 and 1 which can be monitored through the live data much like testing the good old faithful brake pedal switch but the switch operation can easliy be tested with a multimeter for continuity whilst being operated it is just an on/off switch
Back to Top
Kitawagon View Drop Down
Groupie
Groupie
Avatar

Joined: 26 Jun 10
Location: Bath
Status: Offline
Points: 168
Post Options Post Options   Thanks (0) Thanks(0)   Quote Kitawagon Quote  Post ReplyReply Direct Link To This Post Posted: 19 Sep 10 at 00:30
Exactly, your advice is sterling, along with everyone else Beer
Back to Top
VW master-tech View Drop Down
Yardie
Yardie
Avatar

Joined: 28 Aug 09
Location: bedfordshire
Status: Offline
Points: 407
Post Options Post Options   Thanks (0) Thanks(0)   Quote VW master-tech Quote  Post ReplyReply Direct Link To This Post Posted: 19 Sep 10 at 00:31
ahhh the good old brake pedal switch another fine piece of engineering LOL
Back to Top
VW master-tech View Drop Down
Yardie
Yardie
Avatar

Joined: 28 Aug 09
Location: bedfordshire
Status: Offline
Points: 407
Post Options Post Options   Thanks (0) Thanks(0)   Quote VW master-tech Quote  Post ReplyReply Direct Link To This Post Posted: 19 Sep 10 at 00:34
Thanks kita just hope it helps and keeps some money in your pocket for a bit longer unfortunatley the driveshaft and stub shaft repair will soon have those pennies not a cheap repair make sure that you get the modified grease from VW and throughly coat the splines when replacing the stub shaft and driveshaft (dont ask me whats modified about grease have no idea but seems to work LOL
Back to Top
Kitawagon View Drop Down
Groupie
Groupie
Avatar

Joined: 26 Jun 10
Location: Bath
Status: Offline
Points: 168
Post Options Post Options   Thanks (0) Thanks(0)   Quote Kitawagon Quote  Post ReplyReply Direct Link To This Post Posted: 27 Sep 10 at 18:07
Ok so everyone was right. The front right and longer (hence more expensive) of the two drive shafts was knackered. Basically teeth were stripped and the shaft just span. Cost £613 for parts and labour at http://autohausdolby.co.uk/ in Sheffield. Having driven the van now, it is clear that the repair is an improvement as the van now drives! Great! However, I'm still worried something is going wrong somewhere between the clutch and gearbox. First concern is that the clutch pedal has become noticeably easier to press to the floor (softer) and secondly the gear-change seems to be developing a notchiness. Again it's driveable and there is no noticeable clutch slippage but it just seems like a problem (another!) is developing. Paranoia, I hope so, but I think not. These symptoms sound familiar to anyone? There was also the 'peaking (say 500rpm extra) during gear changes under load. But this could be said to be intermittant as I didn't experience it today when accelerating moderately hard.Ermm This pointing to dual mass flywheel troubles?

Cheers..
Back to Top
Kitawagon View Drop Down
Groupie
Groupie
Avatar

Joined: 26 Jun 10
Location: Bath
Status: Offline
Points: 168
Post Options Post Options   Thanks (0) Thanks(0)   Quote Kitawagon Quote  Post ReplyReply Direct Link To This Post Posted: 28 Sep 10 at 20:43
Hi all, just to confirm that your suggestions were correct, I had a faulty clutch switch. Replaced by Gilders VW Van Centre, Sheffield @ £38. Fairly steep! However, they were kind enough to take the van for a drive and provide a good amount of advice regarding other issues.

Now concerning power loss, I'm now thinking that perhaps the turbo is fine and that it is either a cracked exhaust manifold or gasket (you can but hope LOL). I did the test whereby left the engine running, lifted the bonnet and held the obvious flap shut (not sure what it is called) causing the engine to stall and the tell tale puff of black smoke (as if someone lit 5 matches then blew them out) to be produced from the back left of the engine (as you look into the engine compartment - under the air filter area). I guess I have no option but to take it back to the mechanics so they can decipher if it is the manifold or gasket!

Cheers for all your advice. Again Smile
Back to Top
T5 TDI View Drop Down
Vanorak
Vanorak
Avatar

Joined: 05 Nov 05
Status: Offline
Points: 3687
Post Options Post Options   Thanks (0) Thanks(0)   Quote T5 TDI Quote  Post ReplyReply Direct Link To This Post Posted: 29 Sep 10 at 20:49
Maybe a blow at the end of the manifold then.  I might be wrong about this but has anybody else reported a loss of power with an exhaust manifold leak?  Some have thought (including me) that maybe it felt very slightly better once fixed but no obvious loss of power beforehand.  Could be unconnected with the exhaust leak.  You need some proper diagnostics.
 
Re the light clutch, check the brake fluid, the clutch uses the same resovoir.  It sounds like air in the system which means a leak somewhere.  Unfortunately (and stupidly) the clutch slave cylinder is inside the bell housing of the gearbox.  This means the gearbox has to come out to replace it.  The master cylinder would be cheaper to replace if it was that but check the fluid level first.
2004 2.5 174
Back to Top
gregozedobe View Drop Down
Vanorak
Vanorak


Joined: 22 Dec 06
Location: Canberra, Oz
Status: Offline
Points: -998266
Post Options Post Options   Thanks (0) Thanks(0)   Quote gregozedobe Quote  Post ReplyReply Direct Link To This Post Posted: 30 Sep 10 at 16:56
Originally posted by Kitawagon Kitawagon wrote:

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.
 
Lots of people believe the early build T5s had way more than their fair share of problems, and that the later builds were significantly more (but still not totally) reliable as VW started to get their act together (particularly for the 2.5l 5 cyl engine).
Back to Top
Kitawagon View Drop Down
Groupie
Groupie
Avatar

Joined: 26 Jun 10
Location: Bath
Status: Offline
Points: 168
Post Options Post Options   Thanks (0) Thanks(0)   Quote Kitawagon Quote  Post ReplyReply Direct Link To This Post Posted: 30 Sep 10 at 18:11
Hah, just my luck. I guess you couldn't sell a million T5's on good looks alone???Clown
Back to Top
Kitawagon View Drop Down
Groupie
Groupie
Avatar

Joined: 26 Jun 10
Location: Bath
Status: Offline
Points: 168
Post Options Post Options   Thanks (0) Thanks(0)   Quote Kitawagon Quote  Post ReplyReply Direct Link To This Post Posted: 30 Sep 10 at 19:00
Hi there T5 TDI.  Ok that's strange, I was confident that the cracked manifold would cause pressure loss and likewise effect the turbo's performance. But I'm a mechanical punter so that a carries no weight Confused. Certainly with me the noticeable roughness of the engine is below 2000rpm. And there is a really noticeable strange vibration which occurs around 1800rpm and then disappears after 2000rpm when accelerating, almost as if a metal heat shield were loose and this was vibrating (tinkling), that kind of sound, but i have been suspecting that it was the turbo going and then secondly that this could be air leakage from the manifold (because I have seen the black smoke as described when forcing the engine to stall).  Above this things seem to be a lot smoother but I'm still convinced the overall power is down. Now don't get me wrong, I'm not like a slug, and i understand 1st and 2nd gearing is not best suited to racing away at the lights, but really I got wupped at the lights by a double decker Sheffield bus yesterday! EmbarrassedLOL When I was at the VW garage having the clutch switch replaced their suggestion was that the clutch was going, this could be the case I suppose but wouldn't account for any of the rattling noises under acceleration (at 1800rpm) and I have noticed absolutely zero slippage. They told me to stick my head under the bonnet and you can smell clutch, but that was after they had taken the van out and purposefully tried to get the clutch to slip! Less said about that the better.

Now I need help to get my cherished camper running as well as possible, I'm happy to pay someone competent to help me, but where to start? I asked the VW garage if they can pressurise the turbo pipework, including manifold etc. to see if there are any leaks and they said no they can't do that. I then asked them how would you diagnose if the turbo was under performing, they said plug it into the diagnostic system, however, they did that for the clutch switch and said there were no errors shown regarding anything else.

Regarding the turbo exhaust manifold (or gasket), there wouldn't be any black smoke when forced to stall if everything was tickety boo, right? So I know this is needed to be fixed and ticked off the list (with a shoddy VW replacement unless the Stainless Steel heroes deliver the goods!). However, sounds like this will have little or no bearing on power. Confused

After that, my view is that I would like to know if there is any leak in the turbo pipework etc. I'm sure I read somewhere that VW should have the kit available to do this? Should that be fine, then I guess I'm looking at having a mechanic remove the turbo for me, package it up and post it to a turbo specialist to have a look at and service/repair as necessary. Should that be done (probably good practice anyway), I then get it delivered back to the mechanic to fit. Woohoo, so I should be sorted then. Erm. Let's see!

After that I suppose there are other issues to condider such as EGR malfunctioning (sounds best to install a blocking plate), MAF sensor shenanigans, a load of crud deposited in the engine inlet due to the use of EGR?? The list presumably goes on LOL

Sorry for the epic post. Probably totally against forum etiquette!

Out.
Back to Top
energysolutions View Drop Down
Vanorak
Vanorak
Avatar

Joined: 02 Dec 08
Location: Earth (For Now)
Status: Offline
Points: 3684
Post Options Post Options   Thanks (0) Thanks(0)   Quote energysolutions Quote  Post ReplyReply Direct Link To This Post Posted: 30 Sep 10 at 19:43
Has anyone verified that the MAF sensors functioning correctly Kitawagon?
!!Never Eat Yellow Snow!!
Back to Top
mistadave View Drop Down
Yardie
Yardie


Joined: 13 Jun 09
Location: Portsmouth
Status: Offline
Points: 511
Post Options Post Options   Thanks (0) Thanks(0)   Quote mistadave Quote  Post ReplyReply Direct Link To This Post Posted: 30 Sep 10 at 20:49
There was a post on here or on the vwt5 forum who had  fairly similar symptons of low power and a strange kind of vibration as the turbo spooled up and that turned out to be a leaky intercooler.

There is a proper VW dealer tool for testing the air intake system for leaks, or you could ask to buy T5 TDIs clever boost-hose-with-a-tyre-valve-stuck-in-it from his turbo squeal thread.

HOWEVER, from experience of driving 5 miles without the turbo connected to the intercooler (like an extreme intercooler leak), and not because the connectors are crap, but because i didn't put it back on properly, I can safely say the engine shouldn't feel rough, just gutless and black smoke.

A rough feeling, IMO, would tie in more with the EGR being stuck open and causing an unstable combustion or smothering it completely.

A cracked manifold will loose you some power, but obviously it depends how big the crack is. You're right in that if the hole is big enough, you will loose the pressure which drives the turbo. Most of these cracks are fairly small though, and while i did notice an improvement in fuel economy and performance while it was temporarily fixed with gun gum, I could still beat any other van at the lights now it is leaking again.

I don't think it could be the turbo causing the vibrations, if you think the most minuscule of imbalances and a turbo spinning at 200,000rpm would destroy itself pretty quickly, its not going to keep on causing vibrations you can feel, it would be just bang, and its gone.


55 reg 174 LWB raven blue camper. Celtic remap, pipercross filter, MIJ de-cat and exhaust, Forge intercooler, Allard EGR powerpipe and oil catch tank
Back to Top
 Post Reply Post Reply Page  <123>

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.06
Copyright ©2001-2023 Web Wiz Ltd.

The WebThis site