Power loss and noise in tdi

[Awattam]

I have a 90 hp tdi, I've done about 20k in it and it has always run fine, aside from a sticky turbo causing limp mode when I first got it (cured with the mr muscle treatment).

I'm currently on holiday in Ireland and have done about 600 miles since setting off. In the last 200 miles I've had an intermittent power loss. From a constant speed sometimes it will accelerate and increase speed normally, other times I press the accelerator and there is no attempt from the car to accelerate. It can be fine one minute and bad the next.

Initially I thought this might be a blocked filter or overboost/limp mode but it doesn't feel like either (I've had both before on this car).

In the same time I have started to have a horrible clattering noise, the best description I can give is like a badly blowing exhaust or a very old diesel tractor. This too is intermittent and seems to vaguely correlate to the power loss.

I have about 500 miles to do to get home. If this is something straightforward then I can get it fixed while over here. Mostly though I want to diagnose it so I know whether I'm likely to make it home and whether I am likely to do any further damage.

Sorry for the long post, I really need help on this one!

[Awattam]

To add a bit more info...

The noise happens at any revs, but is louder as the revs rise, it sounds exactly like a blowing exhaust or a cold noisy diesel.

The power loss seems to happen at all revs too, pulling away requires a lot of throttle when the issue is present - I stalled setting off at one point because there was so little power available.

The car had new cambelt, water pump, tensioners etc about 6k ago. There is plenty of oil in it and this was changed 2k ago. The car is generally well maintained.

I have no warning lights and it doesn't overheat.

If I think of anything else I will add it! I'm pretty desperate to get to the bottom of this.

[Awattam]

Anybody? This is happening all the time now, after we travelled about 40 miles today. Really quite worried that we're not going to make it home.

[cheshire_cat]

exhaust pipe to egr valve?

[trundlenut]

Any smoke from the exhaust when the problem occurs?

Sent from my Nexus 4 using Tapatalk

[Awattam]

The pipe to the EGR is a good suggestion, I'll check. My EGR is deactivated though, by blocking the tube that activates it.

There's no smoke as far as I can see, and fuel consumption is normal.

I had a crawl underneath today and I can't see any splits or holes in exhaust or boost hoses. I didn't really check the EGR stuff though.

Tomorrow I'll check further with the engine running.

[mac11irl]

Where bouts in Ireland are you at the minute? I may be able to give you a reputable place to get to for a check out if you like?

[Awattam]

In Galway atm but I'm heading up to Fermanagh to stay with family for the weekend this afternoon. If it makes that journey then I've got more faith in making it home. Once I get up there I'll have access to tools etc so I've got a better chance of sorting it if I can work out what's wrong.

[mac11irl]

****e, wrong end of the country to be able to guarantee anyone, never up that way tbh...

 

Hopefully its just something come loose that you cant see/ feel at the mo.

[pauldazzle]

Try unplugging the MAF, it's long shot but only takes a few seconds. MAF failure can cause all sorts of running issues, & doesn't always cause the EML to come on.