I have a 2002 1.9 tdi Ocy 110bhp which has developed a rather large flat spot under load, especially noticable in 3rd gear & 4th gear, when its warm.

The cars only done 50k, with service history (not that that means anything) and ive already changed the air filter (black and full of crap), fuel filter, oil & filter, but the flat spot is still there, mostly from 2800 rpm onwards.

The car had a new turbo at 20k under skoda warranty because of the "overboosting /stuck VNT" problems, and it boosts nicley up to the flat spot.

The car doesnt lose total power just feels very restricted.

I'm leaning towards a poorly MAF sensor?

Would a plug in on vagCOM diagnose this?

Any advice greatfully received!

Matt

just been thinking, that when i get this flat spot, theres a real smell of "heat / burning" coming into the cabin as well.

Plus the turbo sounds very noticable at low revs, and on boost. Could it be something as daft as a leaking boost hose? and the heat smell is leaking exhaust gasses?

Ive arranged a VAG - com plug in saturday morning to try and rule out the obvious ones!

Matt

MAF Sensor, probably.

Unplug it. The car should feel *much* worse. If not, the sensors screwed.

You can confirm by VAG-COM logging MAF actual and expected values while booting it around the block flat out.

It won't neccesarily store any codes for a failed MAF.

[edit]

Just read your 2nd post. Do you have a pipe that has dropped off?

:iagree: I'd do the MAF test first, cos it's easier rather than cos I think it's the problem.

No theres no obvious pipe thats fell off, i meant maybe the start of a split or a loose clip somewhere? Its just the smell of "heat" that made me think of that.

The air filter that i took out saturday morning was very very very dirty. Could that have in effect caused a problem with the MAF sensor?

I know its all irelevant until ive been "plugged in" just picking your knowlegable brains!

It could be a split, or some of the joints down around the intercooler are pretty hard to see without taking off chunks of plastic. Hence why I said the MAF test was easier to do!

There's no "air cleaner bypass pipe", so a mucky cleaner wouldn't hurt the MAF unless someone mucked up cleaning the bottom of the airbox.

Cheers for the responses guys!

I appreciate its a common problem (ive spent hours using the search function today - even though i'm "supposed to be at work LOL"), and i'm grateful for any advice you can give!

Matt

:iagree: I'd do the MAF test first, cos it's easier rather than cos I think it's the problem.

Agree also maybe the MAF and could be a hose split or adrift somewhere.

Quick update - I had the Ocy plugged in yesterday and the first trouble code stored was Coolant Temp Sensor, then they did a number of "on the road" tests with the VAG hand held computer and came up with the MAF sensor being out of range at higher revs.

So it looks like its the cheaper, easier option all round!

The turbo was functioning spot on, so thats another weight of my mind.

Thanks for all the advice folks!

Matt

Glad you sorted it out and a cheaper result !!

Update - Fitted the new genuine MAF sensor and all is well in the skoda camp!

It now pulls much much better through the entire rev range, the funny smell has gone and its all together much more like the 50k car it is!

Mind you, saying that the interior lights now playing up from the drivers door - possible the door ajar switch in the drivers door lock assembly?

never a dull moment in the skoda owning world eh?