Lost Power At Top End

[WSB]

I have a 2004 2.0L Turbo Diesel Zafira. It's always been pretty poky and when cruising at 60/70mph, could always power forward nicely when putting the foot down.
EGR packed up recently, where I had no power all the way through (it had been on it's way out for a while - used to regularly clean it every now and then). That made things better but the top end acceleration was still a problem.
Got engine management light coming on so called AA. AA man suggested changing the MAP sensor which I have done but that has made no difference. The error code was P0234 Boost pressure control "Control deviation positive".
With this sensor changed I haven't seen the engine management kicking in again but then I haven't pushed it.
I'm running out of ideas so worried that the turbo has now gone, which would spell the end of my lovely car (unless I can get a cheap one).
I checked all the pipes around the turbo and sucked on the waste gate vacuum pipe. The level moved fine.
So, firstly, anything else I can try other than the turbo. If it is the turbo, is there anyway I can fix it, get one cheap and how easy are they to replace?
Thanks all!!!

 

[Mottie]

Check there's no blockage in the exhaust. Get someone to give it a good rev or two and feel the exhaust to see if you get a good flow of gasses out of the back. Compare it to another vehicle if unsure. Could be a blocked exhaust.

 

[Burnerman]

Treat it to new fuel and air filters, and take it from there. I wouldn't consider a new turbo unless the car had been seen by a diesel specialist.
John

 

[WSB]

Thanks folks. Must admit, I was thinking the exhaust as well. It does sound a bit rattly back there. Any idea how I'd tell?

 

[Mottie]

A baffle could have come loose inside and turned maybe? Sometimes you hear a 'whooshing' sound as if you had your hand over the tailpipe trying to stop the flow of gasses.

 

[WSB]

Hmmm? Got me thinking there. It could well be as it does sound like a lot of rattling metal back there sometimes. Just been reading up turbos and wastegates etc. Thinking that could also be the issue bearing in mind the fault code I mentioned earlier. Thanks

 

[Peter.N.]

If it has the 8 valve 2.0. engine they are pretty well bombproof, I've certainly never had a turbo fail on one. I think the advice you have been given is good but another thing to check is for a leak in the turbo piping between the turbo and the engine or possibly the intercooler if its a 110.

Peter