2005 BKD PD140 Overboost then turbo whistle and lift-off whoosh

[Jelibeli]

Hi,

 

My 2005 BKD Wagon (PD140) went into limp home today.  When I got to work, it had stored an 'overboost' OBD2 code, probably from last night when I became a child again for five minutes and raced a van away from the lights!!  The turbo was whistling at low revs and again a bit at high revs, and there's a dump-like whoosh when I lift off.  I can hear it more clearly inside the cabin than under the bonnet.  I reset the fault, and it came back in after about 25 miles.  I ran some EGR3 through it (god that stuff stinks!) and reset the code again, and it's stayed off for about a dozen miles so far, but it's still making all the noises.  I've also had an insufficient EGR flow code for several days, but I'm not sure that's connected.  I'm hoping the turbo issue is a pipe off somewhere, maybe even an exhaust hole.

 

Anyone had anything similar?

Edited 15 July, 2016 by Jelibeli

[hobbes42]

That does sound like a pipe off somewhere..sorry can't be any more help

[billywhiz040480]

Split pipe?

[WilliamOctavia]

compressed air leakage?... check the hoses going to the wastegate, if those are damaged the air will not push the wastegate when engine dont need more boost. you overboost.. 

damaged egr valve membrane will not open the egr and let in exhaust gases.. the fault will come because of that.. or the egr hose is simply full of crap.. 

[dstev2000]

Sticking VNT vanes? That can easily cause an overboost. A buildup of carbon from the diesel fumes eventually gums up the VNT ring mechanism.

Sometimes a good decoke sorts it out, but it's a turbo out job to do it properly. It also gives you a chance to inspect for wear and damage, especially end float: exces axial and radial play on the turbine and compressor ends of the shaft.

I've stripped and cleaned an EGR, ASV and intake manifold on a BKD and it was chock full of oily gunge.....

[moiloon]

well ive just overcome this trouble on my mk 5 golf last week after nearly 2 years of heartache lol,

refitted a recon turbo 15 months or so ago, was still going into limp afterwards,  overboost code P0234

its took me this long to find and resolve, chucking parts on as process of elimination (wasted money really, but now I know all parts replaced should be ok for a while lol)

it was a combination of multiple problems and WASNT the turbo, it was a combination of corrosion of all ground points in engine bay, a chaffed wire in harness underneath the battery/air filter box on passengers side chassis leg (I stripped all insulation from engine harness  from the map sensor to the ecu and checked every wire for chaffs/breaks and continuity

, and a leaking egr cooler (which was giving me insufficient flow error too, before I flashed a new map for exta bhp ,egr off, and hot start)

also was getting intermittent fault with the electro mechanical steering because of the corrosion of the engine bay ground points

after doing this my motor boosts like a new motor and no more limp mode,

you may not have same issues but worth checking as ive no doubt in my mind now that I needn't have replaced my original turbo

good luck

[Jelibeli]

Just found this thread, so I thought I would update it - Turned out to be a damaged turbo, had both it and the oil feed pipe replaced, and it's all good as new-ish, apart from the dent in my bank balance.  I've blown a bottom intercooler hose since then, which the RAC bloke thought was down to the overboost (worn clipping points on the end).  £40-ish quid and ten minutes and it was fixed.