Dreaded p0299 Mk2 octavia vrs

[Da21982]

Hi and thanks for reading, I am usually the one giving advise on here but for once im in need of some help,

 

I purchased a 57/2007 Octavia vrs diesel, previous owner fitted a timing belt but didn't fit the tentioner correctly causing the timing belt to slip. 

 

Once I got the car home I re-timed the engine and low and be hold it fired up but idled like it was on 3 cylinders, on further inspection after removing the cam's I found 2 of the exhaust rockers were stiff to pivot on the rod that runs through the head. long story short I have fixed that issue and the car runs like a dream.

 

I took the car on a drive but it lacks power coil light flashed so drove back home and scanned with vcds fault code p0299 Boost Pressure Regulation: Control Range Not Reached....

 

Since then I have tried the following with no luck,

 

All vacuum pipes have been checked for correct routing/leaks 

 

Good vacuum produced by the tandem pump

 

Blocked off the vacuum pipe that goes to the reservoir in the rocker cover 

 

N75 has been tried

 

Air mass has been tried MAF

 

Boost pressure sensor has been tried MAP

 

Timing has been checked and double checked

 

Turbo actuator checked for free movement it will move through the full range with 0.5psi of vacuum 

 

Turbo actuated using miti vac but still turbo will not produce any boost

 

DPF has been disconnected from turbo to check for blocked exhaust 

 

EGR pipe has been disconnected from the EGR valve 

 

Compression check on all cylinders as follows

 

Cylinder 1 420psi around 29bar

 

Cylinder 2 400psi around 27.5bar

 

Cylinders 3 and 4 380psi 26bar....

 

No matter what I do even if I manually operate the turbo actuator the turbo will not produce boost, Only thing left is the turbo itself has anyone ever had issues with a turbo not producing boost even thought the actuator moves as it should. Or am I missing something

 

Thanks in advance 

 

 

 

 

[FatblokeVRS]

We had probs as soon as it was remapped. I think it was the p0299 error when it went into limp mode. Tested the actuator and it was faulty. Replaced but still not right. Eventually had to get the turbo fully reconditioned, DPF and EGR cleaned . It's been fine the last couple of years. It would boost then drop the boost between 2000rpm to 2500rpm then boost again and take off like the proverbial off a stick.

After work was done it's pretty smooth boost now.

 

Edited 9 July, 2019 by FatblokeVRS

[Da21982]

I have no boost at all, I have tested the actuator it moves through the full range without any issues. 

[FatblokeVRS]

A hole in the intercooler maybe? Can you hear the turbo spin up?

Edited 9 July, 2019 by FatblokeVRS

[Da21982]

I had the intake pipe off I can see and feel the turbo spin up, I have even removed the boost pipe from the turbo and still no boost, no matter what I do the turbo will not produce any boost. 

[FatblokeVRS]

Maybe the vanes stuck in wrong position?

 

Not sure if there is a pressure relief valve somewhere?

[Da21982]

no idea, I have tried everything I could think of apart from fitting a new turbo. the only reservation I have is the previous owner said he never had any issues with the turbo before the belt jumped. 

[Excision]

Hi,

 

the turbo actuator moving with only 0.5psi seems like a low pressure to make it work. Is that a normal pressure? You may need to split the turbo and remove the core to inspect it. Having the VNT actuator move may not mean the VNT mechanism/ring/vanes are moving if something internal has failed. It might need an inspection to check it is all ok. When I used to be plagued by the P0299 code it was eventually traced to a vacuum leak for the intake manifold swirl flaps mechanism. Once it was disconnected and plugged the car was cured.

 

good luck.