My wife and I went on holiday to the Yorkshire dales last week, I had the same issue on 3 or 4 occasions.

 

Same scenario every time it happened... Car loaded up, accelerating up a reasonable hill.

 

In either D or S, with the car in 4th approaching 3000rpm the power dropped off quite considerably. Applying more throttle made the engine get noticeably louder, but no power. The revs seemed to be slowly dropping down.

 

Let off the throttle for a moment then back on and it was fine.

 

The car didn't go into limp mode and no lights were thrown on the dash. I've not yet had a chance to scan it with VCDS.

 

I did about 800 miles all over and it only happened 3 or 4 times.

 

I tried to make it do it by using manual, D and S up the same hill it did it on first, but I couldn't replicate it.

 

At first I thought it was the gearbox getting confused as it was a tight corner in a 30mph then straight to national limit.

 

Thinking back I'm fairly sure it did the same not long after I first got the car, but I've scanned it since then and I can't recall anything that would relate to it.

 

The ESP light was definitely not flashing.

 

Car has very recently has the cambelt changed, DSG oil and filter changed and serviced too.

 

Any suggestions?

How many miles has the car done?

 

It sounds like it could be sticking turbo vains perhaps.

 

Phil

It's on 116,000.

 

Sticky veins causing overboost was a thought, but whenever my inlaw's Passat has logged an overboost fault it's gone into limp mode and not just carried on as normal afterwards.

 

When I bought the car I scanned it and it had an overboost fault logged, I cleared it and it didn't show up again the next time I scanned it, even though this had happened in between.

 

The engine getting noisier was my main concern at the time. It went from its normal diesely sound to really gruff and loud.

It might not be overboost but underboost?

 

In that you put your foot down to get up the hill but the veins stick and so the turbo doesn't provide enough boost, you life off and the veins move back and then when you press the throttle again they have unstuck and the turbo boosts properly again.

 

They sound loud and gruff when they don't get enough boost to burn the fuel going in. They sound like this with a bad boost leak.

 

Might be worth checking the movement of the actuator on the turbo.

 

Phil

That's a good point, I hadn't actually thought of it underboosting. There was a huge plume of smoke out the back the first time it did it so that could well explain it.

That's a good point, I hadn't actually thought of it underboosting. There was a huge plume of smoke out the back the first time it did it so that could well explain it.

 

Yup it sounds like it's underboosting. Can't be a leak as it would do it all the time.

 

The black smoke is indicative of this too. The car injected extra fuel as the engine load increased but as there was less air being pushed in by the turbo it came out the exhaust as unburnt fuel.

 

Might need to get the turbo cleaned out.

 

Does it get a thrash every now and then? As in foot to the floor and let it rev right out a few time?

 

Phil

Does it get a thrash every now and then? As in foot to the floor and let it rev right out a few time?

 

Yes I don't hang about. The DSG really helps make use of all the 105 HP, and there's hardly been a time I've wanted more power.

 

If it keeps on doing it, I'll give it a clean with Mr Muscle

I've also found the same.

 

We came from a PD130 Seat Cordoba which went like a stabbed rat.

 

We initially thought it would take some getting used to the drop in power and increased weight.

 

But in all honestly we haven't!

 

I think the DSG really does make up for the lower power and it just seems to fly when you stick your foot down.

 

I managed a 13 minute lap in the wet of the Nurburgring.

 

Plus it's a dream to drive and so willing to sacrifice some power for that anyway.

 

Phil

Well I scanned it with my torque app and it showed no fault codes.

There might not be a code.

 

The best thing you could do are some logs with VCDS monitoring the requested vs actual boost.

 

If the actual is way off the requested then it's pretty certain it's sticking veins.

 

Phil

Well it did it again yesterday even more pronounced than before so will give it a clean with Mr muscle