Another puzzler for you mechs. VW this time.

[ukracer]

Hi

I read with interest about the Astra Norm was having problems with and having an 09 Astra which is useless it does not surprise me.

But I digress. I have a 1.9TDI passat estate that had an issue with a turbo to intercooler pipe splitting. It seems to have more than one problem. Which is why its hard to diagnose. BUT its had a new MAP sensor. )before I found the spit pipe) . since I fitted a new turbo pipe it ticked over like a dog. It also ran awful and seemed to vibrate/osolate up the gear stick rumbling/roaring in the engine bay.

WE took the EGR vaccum pipe off the EGR and it ticks over fine. But still has the "vibrate/osolate up the gear stick rumbling/roaring" but less apparent.....>> MMMMmmm hard to describe the symptoms you see.

When its cold if you push it much it drops into limp mode and no power. If you go on a long run it does this a few times for the first 10 miles and then seems to stop playing up and runs OK. No right but drivable.

I have disconnected MAF and tried it and its no better and drastically down on power.

Its getting annoying now as it shows NOTHING on the diagnostic computers we have tried.

Any suggestions appreciated.

Regards Andy T

 

[normspanners]

HA GUESS WHAT !! I've got a 1.9 passat with the same symtoms !!!! driving me mad also, gives the same symptoms / feeling as a blocked filter. But try switching ign off n back on and its back on full power immediately, so it cannot be a blocked filter I thought about a turbo hose poss sucking down so tried it with car still in gear, engine still turning, switch ign off n back on in half second,car back on full power. NO fault codes and no managment light

 

[Stubradley1]

Turbo pipe de-lamination?
Happens a bit on discoveries ??

 

[stormin]

Do those Tdi's have the variable vane turbos? Sticking vanes is a common problem and could lead to some fo the problems described.

I had an Octavia Tdi that began to run rough, first thought was a dodgy injector but nothing showing on diagnostic. Tried blanking off EGR and no better. Checked timing in case it had slipped a notch on belt, this had happended on a previous occasion. Turned out to be the dodgy soft hydraulic tappets, one had worn through completely and was seized in the head others were sticking. Definately something to look out for. Engine only had just over 70k on and wasnt on the long life sevice intervals either.

 

[normspanners]

Thanks Stu
the hoses feel /look good but the thing is if they had sucked down it would still be restricted if left in gear and switched off n back on but there is immediate return of power.

 

[ukracer]

HA GUESS WHAT !! I've got a 1.9 passat with the same symtoms !!!! driving me mad also, gives the same symptoms / feeling as a blocked filter. But try switching ign off n back on and its back on full power immediately, so it cannot be a blocked filter I thought about a turbo hose poss sucking down so tried it with car still in gear, engine still turning, switch ign off n back on in half second,car back on full power. NO fault codes and no managment light

Lol who would guess you had one of these as well. lol.

I have been working on and off for a few months trying to solve the conundrum. I am not a mechanic but I know a few and they are all pulling their hair out.

I tried to adjust the EGR valve while stationary withe revs on (with a vacuum pump) and it did not like it and started to ossolate a bit like the noise I can hear when I am driving. hence taking the vacuum pipe off the EGR to test.

I did have a similar problem 18 months ago. (I had a cheap chip fitted to the car and it was much better on power and consumption.( I was then told they trick the consumption and took it off)(at the same time we replaced the MAF. The car would suddenly go into limp mode or black smoke would pour from the exhaust. All very random.

We tried a new MAF but that did not solve it. My lad fitted a new MAP sensor and that never fixed it immediately BUT he carried on down to essex. On the way back it all started working as it should and worked fine for a year. Until I got this split turbo to inter-cooler hose.

All very frustrating.

 

[ukracer]

Thanks Stu
the hoses feel /look good but the thing is if they had sucked down it would still be restricted if left in gear and switched off n back on but there is immediate return of power.

I actually fixed the split in my hose as a temp fix with rescue tape What I did not realise is that the hose would collapse after getting hot. But whilst the car did not run correct it did not run that badly and when i replaced the hose there was only abut an half inch hole through part of the hose. lol

Nothing really makes sense BUT a sensor that does not show up on diagnostics IMHO. Changing them all would be expensive especially as they say third party replacements can cause more trouble.

 

[baldylocks]

hi there dont know if this is of any help,
but are your cars fitted with a dpf?
if so it could be failing to regenerate some are controlled via engine management unit and some have no active management and can be removed

dont know how helpfull this is but thought it worth a mention


baldylocks

 

[normspanners]

NO dpf that would have gone in the bin STRAIGHT AWAY !!!!!!
Mine is the 130 hp one but closer too 150 I think. cos it does a genuine 130 mph shown on the sat nav on the flat ( private road of course)
The cheap 'chip' just fools the engine temp sensor by putting a 10p! resister in line to make the ECU think the engine is colder than it actually is, therefore putting in more fuel therefore more power n more black smoke and more turbo vv sticking !
I have a feeling it maybe n57 turbo control valve sticking , I have checked the small vac hoses to it but it could be the actual variable vanes in the turbo sticking. At the moment with all kind of things going on a quick off on with the ign cures it.
BUT it is getting worse !!!!

 

[normspanners]

Until I got this split turbo to inter-cooler hose.

Ah that sort of confirms it, you had your fault when you had the 'SH1TCHIP' fitted more fuel, more smoke, hence more vv (variable vane) sticking. You took off the chip and then it cleaned up by ya son givin it a good thrashin, then you had the turbo hose go, so less air going in the engine therefore an excess of fuel, therefore more black smoke and more vv sticking. I would say your problem is the turbo vanes needs decarbing. When I give mine a good thrashin or a long run it 'cures' it for awhile but it is getting worse but that is prob because the weather is colder and the engine is excess fueling more in the morning and the wife only drives 1/2 mile to work| so the engine never gets to proper opp temp.

 

[gavuk]

the wife only drives 1/2 mile to work| so the engine never gets to proper opp temp.

Make her walk....

 

[normspanners]

Make her walk....

HA YOU MAKE HER !!!! I have to sleep like dog as it is, with one eye open just in case!!!

 

[normspanners]

I've told her, she says the car will have a good run to Wiltshire, she's set off, but I'm not sure whats she's gonna do with the rollin pin she took with her----------------
if ya cant bend over tommorow Gav i'll know!!

 

[gavuk]

She has to find me first ........Its got to take longer for the windows to clear some mornings than it would take to walk.....I'd tell her its broken

 

[normspanners]

She complains if I park at the end of the drive !!

 

[justmental]

try changing the mass air flow sensor.
had this happen on one before kept losing power first start would not rev then after a few seconds it would no faults showing even had the same thing with a golf doing the same bad idle would rev no problem always had power but nothing on the ecu cods's etc nothing stored and was the mass air flow sensor as well.

 

[normspanners]

Thanks but, if you see the first post, MAF has allready been done, this, I think is more a case of overboosting due to carbon build up on the turbo or its control

 

[AndyStobbs]

In both cases here, OP and normspanners,
Are your cars common rail or old TDI? In the case of the latter have you done an injection timing check?

Compression check too, they bend rods quite alot apparently.

If it was overboosting you would probably get an error to that effect.
Also with blanking the EGR its normal for the note to change at idle.

Have also done one golf GT TDI that had a split intercooler, was impossible to hear air escaping whilst fitted and engine running, but showed up immediately once the IC was tested in a water bath. Repair was bourne out by much better pick up with new intercooler.

 

[finyuk2005]

my sister had a passat that was just dead as anything, turned out to be the N75 valve, worth a look..
you can actually swap it out with the one for the EGR control, they are the same valve

 

[normspanners]

Are your cars common rail or old TDI? In the case of the latter have you done an injection timing check?

Compression check too, they bend rods quite alot apparently

Hi Andy
TDI cant see it being timing or compression because it would not go from no power to full by switching ign off n on immediatly
as I have said when mines going ok, ITS GOING!! 130mph!