D5 "Dump Valve Sound" / Slow Turbo Response Cure

[bobmccann]

Hi chaps, a newbie here,
I have been getting fault messages for a little while now, but when I started getting 'Engine Service Required' I thought I had better take notice (going for a Bosch Diagnostic next week).
Deciding to clean out the turbo control governor I wasnt expecting to find loads of carbonised oily gunk in the rubber pipe that you have to take off, and where it joins at either end. There was loads of it (actually I managed to scape out about half a punnet load - an old punnet being the only thing to hand to scrape it into!). The diameter of the joint into the tube was reduced by about 40%.
When I finally finished the job it all looked much cleaner, but I assume that there are similar deposits throughout the system.
Should it be there to that degree or is this a symptom of something else being blocked? Am I looking at something costly to get this cleaned out (I dont think my skills would stretch to much more than what I have done today).
As for the governor valve, it certainly made the engine more responsive, although I did get an Engine Service Required before it had warmed up. After a restart didnt get it again.
Any comments or advice gladly received.
Cheers
Bob

[outnumbered]

there are a few that may read the codes for you, as for the message it could be anything but i would put half a crown on ECM 6805 code.
mike

[Dynosaur]

The gunk is a mix of exhaust soot from recirculated exhaust gas and oil vapour from the crankcase.
The only way to stop it completely is to block the EGR valve (and/or do an EGR delete) - which will mean no more soot recirc.
But if you go that route, be aware that there are questions over increased combustion temps, cooked turbos and burnt exhaust valves.
Most incline to the opinion that it's not an issue - but until we get meaningful stats, the jury's out.
The upside is substantially reduced engine wear - not least from oil that doesn't have to cope with all the soot.

[DAitchison]

Hello all.

I've noticed the increase in turbo noise recently, mostly during spool up then a distinctive sound of the boost dumping. Takes me back to my jap days! Anyway, something else i've notices is that i seem to lose boost, or at least the boost drops mid gear again giving the distinctive sound.

Could this little job help?

[Tim62]

Glad I found this thread, had that psssst noise and didn't know what it was, thought the turbo was on its way out! Thankfully, after following the "how to" on here, the noise has (almost) gone. I say a almost, there is still a little noise there but was thinking of cleaning it out again. was just wondering if there is only a certain amount of cleaning to be done to these valves before its time for a new one and are there any more such valves that would benefit from a blast of carb cleaner?

[Rawhide]

I've just tried doing this procedure and I have removed the device. However where I was expecting to see some sort of filter that needs cleaned instead there is a small plastic screen over the valve.





Is this a later type of controller that can't be cleaned? I've blasted it from below with carb cleaner and will re-install in a little while.

I don't think I can be doing anything wrong (yet!)

[A lex]

Here's an interesting one, grateful to hear any thoughts.....

My D5 had the typical whoosh/dump valve noise and a sluggish turbo. If you told me it had been taken to the Max Power brigade for a dump valve I would have believed you, it was that noisy!

I cleaned the valve about 3 weeks ago, it was a little dirty but nothing terrible and it had no real affect on things.

However I have today changed my top engine mount; the old one was completely goosed - it fell to pieces in my hand when I took it off the car.

Theres a new square one on there now - and hey presto no more whooshing and a marked improvement in the turbo response. The improvement in the dump valve sound is like night and day, I cant quite believe it

So how would changing the top mount affect the turbo side of things?

[BestGear]

Originally Posted by A lex

Here's an interesting one, grateful to hear any thoughts.....

Perhaps the engine was moving more before the mount change and the noise was from a leaky lower engine mount not the control valve?

David

[BestGear]

Interesting that the volvo replacement valve is circa £140 retail when VW/Skoda/Audi use a very similar valve (with a pipe exit not wee filter) and they are £40 new!

[BestGear]

Hi

I just removed mine at lunchtime to give it a clean, and as I suspected, its the same unit as Audi/VW fit - but this one has a CLIP ON filter.

You can see in the pictures below its the same unit.... and with the filter removed, its much easier to clean.







For reference, the VW/Audi part number is 1J0906627A / 1K0906627E