1.9 tdi power loss

[habibi]

Hi,

My 110 HP octavia started to loose power during accelerations, especially when driving on highway. Sometimes it goes ok, but sometimes 60 mph is the limit and car does not respond to the accelerator if You want to go faster. I started to suspect clutch, because this usually happened during full throttle on inclines. If it is clutch i presume the RPM should go up, without the car going faster, but in this case RPM are rising on slowly. Also sometimes car goes ok, so in clutch going dead case the situation would only get worse in time and it is not rapidly getting worse. Maybe it is of some electronics inside which prevent them from rising if the flywheel is not delivering the powe. VAG does not show any errors (Ross tech software). If it . I bought car second hand and presume, that clutch had went 200 thousand km. without the clutch change.

[cheezemonkhai]

Check all the vacuum hoses for leaks especially the small one under the main intake pipe from the airbox.

Check/replace the MAF as if this has not been changed in the last 60k it's probably had it.

I doubt it's the turbo as this would being on a warning light, so once you've done the MAF give it some booting and hopefully keep this free and working.

As for the clutch, change from 2nd to 4th and try accelerating a bit. You will soon know if your clutch is dead.

[greg123]

If you accelerate hard in 3rd gear, does the engine 'die' on hard revs/hard load and they stay 'flat' and 'lifeless' untill you restart the engine, when it goes well again?

If so it's the VNT issue putting you in limp home mode.

Greg.

[cliver]

probably sticking vnt. look up vnt turbos on you tube for animated picture of how it works.my 130 octavia goes into limp home mode clears on restart,vnt actuator seems to move 2cm when pressed from above with long piece of dowel ..any ideas anyone,please?

cliver.

[dreddnaught]

Not sure if it's the same issue or not but I've been having the same sort of thing, no power when I press the accelerator hard. I've spoken to the Skoda dealer about it and they it's the turbo that needs the filters cleaning.

I've got it booked in at a 3rd party place for a service so they're going to have a look at that at the same time

[cheezemonkhai]

If it's VNT you should get an overboost logged and the car will go into limp home mode.

Hence I don't think it's the VNT.

[pikpilot]

A quick test is to stop at the side of the road when convenient, turn off the engine and then restart. This resets the "limp home" mode and the car will be ok until the next time you go over 3000 rpm (more if hot) and trip out again on overboost.

Look at Small Engine - Small Vehicle & VW TDi diesel servicing specialists in Nottingham for more info. Click on VNT turbo rebuild on the second paragraph on the left hand side.

Mike

[greg123]

The actuator doesn't have 2cm full travel when new!

Get a full fault code scan I can look at. Also get a graph of requested vs actual boost, this will show what's going on. I then go through some output tests and diags to eliminate the control system.

This changing the maf anyway and replace all the pipes - I'm not of that opinion. I have cars with 220,000 with original MAF just fine. I have rebuilt quite a lot of these VNT's and so far not a single one has been a vacuum leak, it's always been the VNT mech sticking.

Also if you can move it is not a good test. It's if it moves smoothly, under the pressure the actuator can deliver, that counts.

Greg.

probably sticking vnt. look up vnt turbos on you tube for animated picture of how it works.my 130 octavia goes into limp home mode clears on restart,vnt actuator seems to move 2cm when pressed from above with long piece of dowel ..any ideas anyone,please?

cliver.

[fordfan]

Log on Vag Com, advanced measuring blocks actual and specified mass air flow, play it back on Vag scope and if the actual is way below the specified, it'll stand out. That's sufficient in my book to condemn the MAF in the abscence of fault codes.

I agree that a stuck VNT will show a charge pressure control deviation fault, but I have as yet to see one put the engine light on. The light doesn't come on for every fault, only those that affect the emissions.