My 1.9 TDI Octavia II has run as sweet as a nut for 5 years,.

Today I heard a song of "ching" noise from under the bonnet, no immediate effect but it has now lost a lot of power.

It will not pull at all in 5th and is slow off the mark, particularly in 2nd and 3rd gears and generally feels gutless.

There are no warning lights, no black smoke and no obvious hoarseness in the engine noise, though it does sound a little louder than it did. It starts and idles fine.

I cannot see any obvious pipes loose or split but then I do not know for what to look or where to look.

EGR? Turbo? Any thoughts?

My apologies in advance if this has been covered - please send me the link. Thanks.

My 2l has done the same yesterday. Except I did not hear any strange noises at all. Any ideas anyone??

Grrr....

Fuel pump?

Sudden loss of power sounds like a lack of turbo boost problem.

but torbo would be more instant and noticable?

A faulty air mass meter ?

A faulty air mass meter ?

Agree possibly this.Unplug it and see if it runs better.If it does then thats your culprit.Have you changed the air filter recently?

All I can add is that next day, once the ignition was swtiched on and off three or four times it came back to normal.

The Engine Management light did not come on but I'm half expecting some code to show up next time it's serviced.

Had gradual power loss on my 2001 Fabia 1.9 tdi over the last few months. Thought it was the turbo but tried disconnecting the MAF sensor to test it as suggested on this forum. Low behold, it was a different car with it disconnected. Loads of power! Now replaced the sensor, reset the fault code, runs like a dream thanks to the good advice here.

The problem with detecting a faulty MAF sensor (and this is key), is you don't get a fault code! I have since found that my ECU warning light doesn't work so that wouldn't have helped anyway. Makes you wonder how many people pay for a new turbo as the symptoms are so similar to having no turbo boost.

Anyway thanks again guys....

Switching the ignition on and off didn't sort my MAF sensor out. The failure mode it went into was permanent and didn't cause any fault codes (using fault code reader). If the problem occurs again I recommend unplugging the sensor to see if the power returns. Doing that will cause a fault code so you will need to reset it after the test.

Never taught my 1.9 ever had power to start with lol

I have an almost the same problem.

2009 plate 1.9 with 82,000 miles on the clock - giving it some welly to join the motorway and at 4,000 rpm sudden loss of power - no warning lights at all.

Took it to the garage - they diagnosed either faulty Turbo or Sensor - changed the sensor as this was a lot cheaper. Also bought some Diesel Turbo Cleaner from Forte for it.

Had that in for 2 days and yesterday the same thing happened again at 3,900 rpm - but turn off the ignition and restart the engine almost immediately - problem gone.

Is this the Turbo or is it the MAF or is it something else??

No obvious smoke out eh back, but it does seem to use more fuel than my wifes almost identical Octavia.

I'v only had this car 2 months and I am worried I have bought a lemon.

Any help appreciated

Thanks

That sounds like its going into limp mode. There maybe a turbo over boost fault logged if you get it scanned. Obviously recycle the ign and the fault goes away. It's possible the vnt veins in the turbo are sticking.

I used the same Forte additive and it has behaved itself since I did a 200 mile motorway trip in no higher than 4th and some spirited uphill sprints.

Still really none the wiser as to why but there seem at least three potential causes from postings her and other VW / SEAT forums, viz.

1. Restricted DPF - try regeneration through a good long run - or additive - or a new DPF

2. Sticking turbo vanes - try fuel additive - remove turbo and use oven cleaner - replace turbo

3. Faulty sensor - replace with genuine replacement - not Chinese copy.

It will be either 2 or 3 because the 1.9 doesn't have a DPF.