Over the last month or so my diesel 2.0 140ps tdi Touran seems to have
developed a occasional shudder through the driveline when driving on very
light throttle (which I appeciate is a nonsense with a diesel but you know
what I mean).

It usually occurs around 1400 rpm almost on the point of being on full
over-run and then the engine seems to misfire or something, causing a bit of
drive train shunting. It's not something I've ever experienced on a diesel.
It's more pronounced when the engine is cold but can occur anytime..

It's almost as if the fuel cut-off is cutting in prematurely. It's been
hooked up to the main dealers computers but they're not reading any fault
codes.

The car recently had a routine service where the wrong engine oill was used
(15w/40) but this was changed for the correct stuff a few days later so I
don't think this can be a factor.

FWIW its a DSG auto but I doubt this makes any difference.

Anyone come across anything similar?

Tim

"Tim Downie" wrote in message
...
Over the last month or so my diesel 2.0 140ps tdi Touran seems to have
developed a occasional shudder through the driveline when driving on very
light throttle (which I appeciate is a nonsense with a diesel but you know
what I mean).

It usually occurs around 1400 rpm almost on the point of being on full
over-run and then the engine seems to misfire or something, causing a bit
of drive train shunting. It's not something I've ever experienced on a
diesel. It's more pronounced when the engine is cold but can occur
anytime..

It's almost as if the fuel cut-off is cutting in prematurely. It's been
hooked up to the main dealers computers but they're not reading any fault
codes.

The car recently had a routine service where the wrong engine oill was
used (15w/40) but this was changed for the correct stuff a few days later
so I don't think this can be a factor.

FWIW its a DSG auto but I doubt this makes any difference.

Anyone come across anything similar?


Does the DSG equiped vaient use the DMF ? If so, could well be the
problem...

Otherwise its likely to be a slightly sticky EGR valve.

Tim..

Tim.. wrote:


Does the DSG equiped vaient use the DMF ? If so, could well be the
problem...

Otherwise its likely to be a slightly sticky EGR valve.

Tim..


Don't know if the 2.0 TDI was affected, but there's a known 'issue' with
later (Euro IV) 130 TDI PD 1.9 engines with precisely the sort of
problem described- I've driven a Fabia vRS (Euro IV) with the problem,
but my Euro III car is not affected. There's a fix that involves a
modified EGR valve gasket, so I think second Tim may be on the right lines.

I believe a twiddle with VAG-COM can disable the EGR...

Tim.. wrote:


Does the DSG equiped vaient use the DMF ? If so, could well be the
problem...

Sorry, you've lost me. DMF?


Otherwise its likely to be a slightly sticky EGR valve.

Cheers. Two votes for that now. I'll ask the garage to check that out.

Tim (the OP)

"Chris Bartram" wrote in message
...
Tim.. wrote:


Does the DSG equiped vaient use the DMF ? If so, could well be the
problem...

Otherwise its likely to be a slightly sticky EGR valve.

Tim..


Don't know if the 2.0 TDI was affected, but there's a known 'issue' with
later (Euro IV) 130 TDI PD 1.9 engines with precisely the sort of problem
described- I've driven a Fabia vRS (Euro IV) with the problem, but my Euro
III car is not affected. There's a fix that involves a modified EGR valve
gasket, so I think second Tim may be on the right lines.

I believe a twiddle with VAG-COM can disable the EGR...

It can, and should be the first thing to be done!

Tim.
..

"Tim.." wrote in message
...

"Chris Bartram" wrote in message
...
Tim.. wrote:


Does the DSG equiped vaient use the DMF ? If so, could well be the
problem...

Otherwise its likely to be a slightly sticky EGR valve.

Tim..


Don't know if the 2.0 TDI was affected, but there's a known 'issue' with
later (Euro IV) 130 TDI PD 1.9 engines with precisely the sort of problem
described- I've driven a Fabia vRS (Euro IV) with the problem, but my
Euro III car is not affected. There's a fix that involves a modified EGR
valve gasket, so I think second Tim may be on the right lines.

I believe a twiddle with VAG-COM can disable the EGR...

It can, and should be the first thing to be done!

Doesn't that mess with emissions?

Tim (OP)

Tim.
.

Tim Downie wrote:


Doesn't that mess with emissions?

Yep. But who is to know? It will still pass the MOT test. TBH I reckon
the way they got the 1.9PD to pass euro IV was by overcooking the EGR.
Digesting ones own ****e, as it were.

Tim Downie wrote:
Tim.. wrote:

Does the DSG equiped vaient use the DMF ? If so, could well be the
problem...

Sorry, you've lost me. DMF?

Dual-Mass Flywheel.

A flywheel that is split, with some variety of damping mechanism between
the two bits. I don't know the detail, but some are springs, some a type
of grease. It acts kind of like a more advanced clutch plate spring and
absorbs some vibration/harshness in the drivetrain.

I reckon it's the EGR though. The DMF apparently rattles like buggery
when failed.

"Chris Bartram" wrote in message
k...
Tim Downie wrote:


Doesn't that mess with emissions?

Yep. But who is to know? It will still pass the MOT test. TBH I reckon the
way they got the 1.9PD to pass euro IV was by overcooking the EGR.
Digesting ones own ****e, as it were.


EGR reduces combustion temperature, and thus oxides of nitrogen. On the
other hand there is less oxygen and more crappy combustion so you get more
soot.

Too much EGR creates soot. The oxidation cat / soot trap can only absorb so
much, some has to come out the tailpipe.

Tim..

Chris Bartram wrote:
Tim Downie wrote:
Tim.. wrote:

Does the DSG equiped vaient use the DMF ? If so, could well be the
problem...

Sorry, you've lost me. DMF?

Dual-Mass Flywheel.

A flywheel that is split, with some variety of damping mechanism
between the two bits. I don't know the detail, but some are springs,
some a type of grease. It acts kind of like a more advanced clutch
plate spring and absorbs some vibration/harshness in the drivetrain.

I reckon it's the EGR though. The DMF apparently rattles like buggery
when failed.

Any tips on how to disable the EGR on a tdi Touran?

If I've understood correctly the options are

1) fiddle with VAGCOM (unfortunately not an option open to me),
2) a bit of electrical disconection (which I believe lights up a warning
light that would annoy me),
3) block pipe from exhast to inlet?
4) block vacuum pipe that powers the EGR?

Tim