Loss of power midrange

[sebbehof]

Hey!

I have an Octavia 4x4 1,8t from 2003 (Engine code: arx) with about 280 000 km's on it. I has run fine until a couple of days ago when it started to lose power in the mid range (between 2500 and 3500 rpm). The engine starts as it should and if you rev in it neutral you don't notice anything. But when you drive (it happens on all gears) and push the throttle over 50 % the car looses almost all power between 2500 and 3500 rpm. And sometimes it even makes bangs throug the exhaust. (only at full throttle between 2500 and 3500) But if you don't push the throttle over 50% the you can get past 3500 rpm and above that the engine runs normal. The engine also runs normal under 2500 rpm. The engine also takes a lot more fuel than it did before. 

 

There are no wierd noises from the turbo, no check engine light, no smoke, no loss of oil.

 

Any ideas before I take it to the mecanic?

[MikeTheThinker]

1 hour ago, sebbehof said:

Any ideas before I take it to the mecanic?

Water in the fuel pooling at the bottom of the filter?  Or maybe one of the vacuum hoses from the turbo is leaking/has dropped off?

Edited 11 July, 2021 by MikeTheThinker

[sebbehof]

21 hours ago, MikeTheThinker said:

Water in the fuel pooling at the bottom of the filter?  Or maybe one of the vacuum hoses from the turbo is leaking/has dropped off?

I don't think the fuelfilter was changed during the last service so maybe that's were I should start. Shouldn't the car give any error codes then?

[absolutuk]

I had a similar issue with a 1.8t(AUQ) and it turned out to be a faulty spark plug - the issue only showed up when the engine was under load.

[mac11irl]

could also be a coil pack. they have a habit of dying too.

 

get ut plugged in and scan for errors, if none then try and do some logging as it may only show on the move. if fuel consumption is gone up too, then its possibly/probably an airflow issue - its losing (or thinks irs getting more- maf) air somewhere and over fuelling