Is it just the Turbo?

[Smevin]

Hi there. I'm new to this but in desperate need for some advice.
In September last year I bought my Dads ex-Taxi off him cheap. Skoda Octavia 1.9 TDI 130bhp 6 speed '04 115k miles. He'd really looked after it being an ex mechanic, and I was well chuffed with it.
A month ago I noticed a very slight juddering when accelerating hard in higher gears at low revs. This gradually got a lot worse over the next week. My Dad and his mechanic mate suspected it was a driveshaft problem, but it was then that I started to experience power loss. It was always at its most noticable again in gears 4, 5 and 6. when accelerating slowly in the high gears the power delivery seemed very on off, on off, in very quick succession. When accelerating hard it is very under powered and there is a noticable amount of black smoke from the exhaust. The juddering by this time was very bad when accelerating hard from low revs, worst in 6th gear but wasn't at all appareent when driving conservatively.
As you've probably noticed I have continued driving it, but very conservatively. It has been getting less powerfull the more I drive it, and consequently the juddering has lessened. I eventually took it to a Skoda dealership where they did diagnostics and my worst fears came true. They found no fault with the injectors or drivehaft, check timing marks all ok, carried out test plan for turbo and found it to be faulty and quoted me near £1,000 to fit a new one.
I just can't afford that.

Does this sound like it is just the turbo ?
Could it be something on top of that?
Should I have been given some fault codes?
Is there a way to find out whats exactly wrong with the turbo to get it fixed?
Thanks for reading . Any advice would be very much appreciated.

Cheers. Smevin

[greg123]

I regularly rebuild the VNT's of these turbo's, that's normally what it is. However I can't say more unless I can scan the car or you can post a full fault scan. Normally seized vnt results in 'limp home' mode if it's overboosting, meaning all of a sudden you lose 50% of your power and don't get it back till you turn the ignition on and off.

[STEWY L]

you sure the clutch is ok?

[edc]

Hi
Check all air intake pipes, exhaust for blockage and get someone who knows what they are doing before spending £1000.00.
Worked on tdi vag diesels from early 90's never fitted a turbo for boost problems as yet.

[Jules59]

Accelerating hard from low revs will evenyually kill your DMF which maybe what has happened here as well as the turbo. In my experience knackered turbos dont induce much vibrations just loss of power. Unless you then press the loud pedal harder to compensate - you will then overfuel it and get loads of black smoke and vibrations from the DMF , especially at low revs.
Best wishes.

Just my opinion, but I could be wrong. Just for the record - Im not a trained mechanic but I have serviced cars for 35 years - inc engine and gearbox rebuilds.

[greg123]

Not quite. Because the MAF and the cross calculation determines that you are not getting much air, so it won't inject much fuel. A low boost still gives clean power on the modern tdi, no overfueling - ever. What will happen is a loss of power as it won't fuel up till the turbo ramps up.

Agree about DMF.

And insidentally yes, I have had them in with this condition and theory meets practice. Common when the VNT is seized in the low boost position and it won't ramp up on power till about 2,500rpm but won't smoke, vibrate or do anything wrong not even a fault code. Just won't GO will the turbo is fixed! Very common.

Greg.


Accelerating hard from low revs will evenyually kill your DMF which maybe what has happened here as well as the turbo. In my experience knackered turbos dont induce much vibrations just loss of power. Unless you then press the loud pedal harder to compensate - you will then overfuel it and get loads of black smoke and vibrations from the DMF , especially at low revs.
Best wishes.

Just my opinion, but I could be wrong. Just for the record - Im not a trained mechanic but I have serviced cars for 35 years - inc engine and gearbox rebuilds.