Any mechanics about?

[brianblock]

got a problem on the car
Octavia tdi 2007
Problem seams to occur mostly after heavy rain
Driving like normal then it’s as if it’s just stalled, sudden loss of power ( seams to mostly occur under slight acceleration) you can pump the throttle pedal does nothing whatsoever you’re just coasting, but dip the clutch and you’re back to normal operation.

My error code scanner shows nothing and I’ve had it into a VAG independent specialist who found no codes or fault on a test drive even though it was playing up on the way to his workshop

 

[stuvy]

Sounds like a turbo fault the vws are known For them but I can’t remember off the top of my head

 

[p0689109]

Locate ECU and have a look to see any signs of corrosion due damp by pulling plugs and inspecting pins. Refit and test drive.

 

[Ruffian]

2007.
Is that the last of the 1.9 or the start of the 2.0l engines??

 

[brianblock]

1.9 tdi pd 105bhp

 

[Ruffian]

Injector wiring loom, can be a common fault

 

[brianblock]

And would that not throw up a code?

 

[earthman]

If it only happens after heavy rain, that makes me think that water must be getting into something somewhere.

Too many wires and places for them to rub on modern vehicles so good luck finding the fault. Computers don't always 'see' a fault to trigger a fault code, I've experienced that myself on an Alfa GTV some years ago, it's oxygen sensor had clearly failed by the terrible mpg and soot black tail pipe but the warning light never came on.

 

[Moose McAlpine]

got a problem on the car
Octavia tdi 2007
Problem seams to occur mostly after heavy rain
Driving like normal then it’s as if it’s just stalled, sudden loss of power ( seams to mostly occur under slight acceleration) you can pump the throttle pedal does nothing whatsoever you’re just coasting, but dip the clutch and you’re back to normal operation.

My error code scanner shows nothing and I’ve had it into a VAG independent specialist who found no codes or fault on a test drive even though it was playing up on the way to his workshop

Definitely no faults codes in any modules?

Sounds to me like a dodgy clutch switch.

 

[Ruffian]

If its water or wiring fault. Usually at front of the gearbox where the loom runs back to the battery.

Or the multiplugs on the ns chassis leg.
Will need looking into but make sure the basics are done like battery terminals are tight and clean and the earth to the ns strut top is clean.

 

[brianblock]

Ok I’ve managed to borrow a vag-com and have 3 engine codes

005661, 005659 which I believe are number 2 & 4 glow plugs open circuit
And 000564 which I believe relates to boost pressure, excess of

 

[Moose McAlpine]

Can you get a screenshot of it?

 

[brianblock]

Not at the car now and I cleared the codes but this is what I copied into notepad

 

[p0689109]

Use the P numbers for the description of the faults. The P1*** codes are manufacturer specific but the other one is a generic code as you quoted.

 

[anto44]

Turbo issue if you're getting an overboost fault, common issue with these engines

 

[brianblock]

Latest update

It played up really badly on my morning commute for the first 20 minutes to the point of being barely drive-able at times, then we’ll behaved for the rest of the hour journey
Couple of hours later I ran it round to my local spanner twiddles and they reportred only 1 old fault code number 2 glowplug
It behaved all the way home and vag-com shows no fault codes at all

So now it’s a waiting game, waiting for rain and checking for codes I guess.

My gut feeling is the sudden lack of power and the overboost coda are unrelated and the actual fault causing the issue doesn’t present a code, I’m thinking a wiring issue maybe the ecu or injector loom as a couple of you have suggested

Anyway I’ll probably be so ****** off with it by the end of the week if it persists I’ll have bought a new motor

 

[anto44]

If the ECU detects an overboost condition it immediately cuts power completely, overboost on those cars results in a loss of power.

 

[zx9]

Not at the car now and I cleared the codes but this is what I copied into notepad

View attachment 187239

Have you looked on the VCDS / Rosstec wiki, it should help or alternatively get a legit copy of VCDS with the data base unlocked.

 

[brianblock]

Ah ok thanks
Looks like turbo needs attention then, sounds pricey shame really it’s just had mot, new brakes all round, full service inc cam belt in last month

 

[Moose McAlpine]

When the turbo vanes stick resulting in overboost and the car goes into limp mode that will only reset with the ignition being cycled.

If putting the clutch in consistently resolves the issue immediately i would start with adjusting the clutch switch. While it may not be the cause, adjusting it costs nothing to try and faulty clutch switches on VAG cars have been known to cause intermittent loss of power.