octavia 1.9 BXE engine sudden loss of turbo

[miker100]

Hi there

 

Can someone help please with a frustrating problem, Went into town on the hottest day of the year a couple of weeks ago with no problem. Parked for about 3 min then tried to drive home. Car started hesitating and no power- seemingly no turbo, Got home, plugged in odb dongle and up came MAF. Bought new one- same problem  Now I have a new fault on odb stating Boost Pressure sensor - bought new one- improvement, but still no turbopower. Checked variable vane actuator -working fine- took EGR apart, cleaned and replaced- working ok too. All vacuum lines working and no leaks. But if I remove the MAF connector, the car no longer hesitates and manages 70mph, but still no power- same with the Boost pressure sensor.

Then I noticed that the throttle reading stayed at 100 and never changed throughout the rev range, although the pedal obviously works. Does anyone think that my problem might be pedal sensor related and how easy is it to change.

Many thanks

 

Mike

[tamiyaandy]

Hi Mike, I would suggest looking at the Throttle position sensor based on the readings its giving you, Try unplugging it first and reconnecting to ensure all is clean and tight.

 

Also as you say you have no turbo input, Can you hear it spoiling up?, Does the engine feel like its holding back or does it just feel flat?

[miker100]

Tamiyaandy- thanks for your input, but I have now changed the MAF, the Booster sensor, the Accelerator pedal, cleaned and tested the EGR (run the car with EGR vacuum pipe disconnected and blocked off- runs better, but still no power with EGR' unplugged') Car starts well, idles perfectly and from cold, takes off almost normally. Can feel a slight surge at around 2200rpm, which implies the turbo is working, but then, as speed increases, it is as flat as a pancake and won't rev beyond about 3000. Engine light comes on after a while. Car still does 90mph, but takes forever to get there, So, fuel appears not to be a problem. Have manually operated turbo vane lever -moves freely. Was going to give it the Mr Muscle treatment in case the turbo was gummed up, but on my car the EGR pipe is S shaped and does not seem to go straight into the turbo, so I held back. Don't fancy sticking that stuff in unless I know where it's going. There is a vacuum operated gubbins to the right of the inlet manifold (as you look from the front) is that a waste gate control? because my OBD keeps coming up with 'Underboost', which would presumably be the case if a waste gate was open. Any idea what solenoid N75 does? Next stop is the ECU, but I haven't a clue where the bugger is- any idea?

if someone could help, I would be obliged, before the men in white coats take me away

 

Mike

[tamiyaandy]

The black box with all the vacuum pipes is a distribution block, Make sure there are no splits or loose pipes in that area.

 

There is no waste gate on a VNT turbo so there are no issues there, The fact that the error is coming up as "underboost" would obviously fit with your symptoms, but as for the answer I am not sure, it appears you have checked everything, it must be frustrating.

 

I have a perfect working Touran for sale shortly if that helps?

[miker100]

Hi there - any ideas anyone please? Octavia 1.9TDI BXE engine, 104000 miles Following my seemingly permanent limp mode with turbo only on start up - but as soon as I get to 3000rpm  back comes the limp - mode. Car still does 80MPH but takes ages to get there. So far changed the MAF, Boost sensor, throttle pedal, and Solenoid Vacuum block with no improvement. Decided to see if the vane operating lever goes through it's full travel today and killing two birds with one stone, did an oil and filter change at the same time. Lever travel OK and smooth. Filled up with oil and let it tick over for about 5 mins to let the oil get to where it should be then went for a spin. As I pulled off the drive there was a hollow BANG and the exhaust note changed. Revs didn't change and it still starts and runs well stationary.There are no strange noises either, I now have NO boost at all and suspect that the Turbo has blown. Went down the road- car acts just like it did before, very little power, but absolutely no boost at any revs -It's like I'm driving a Non Turbo car. There is also quite a bit of oil in the charge air piping, but NO smoke coming out of the exhaust, which is quite baffling. Any ideas please before I sling the damn thing in the cut? By the way, car hasn't even hiccupped up to now.

 

many thanks

 

Mike Randall