Once again another question as I cant seem to find a decent answer online..

 

Anyone know where the N75 valve is on a PD170 octavia MK2? (believe BMN engine code)

 

Am i right in thinking its just to the left of the dipstick? (little grey cap on it)

 

 

Had flashing glow plugs briefly the other day, logged a p0299 powertrain error but after turning off and on again been fine, driven 300 miles since but think I could have issues with either valve, vanes in turbo, MAF etc but want to start with sensors before looking at the turbo being a problem.

 

Cheers in advance

 

 

I am also interested in this. Same error. Same problems. 

Still no answer?? have all of the people on here gone to sleep? im sure this isnt the first time this has been covered, in fact i know it isnt, but i can only find posts relating to either PD140 or TFSI engines.. come on, surely someone knows??

 

Dont think my issue is turbo or actuator related as I took it out today and took it to the red line in first 4 gears and it was fine... slight flat spot though at about 65 in 3rd..

 

so come on peeps, help a brother out!!

Is it similar to the PD140 Engine where it is part of the Solenoid block ?

 

Have you traced back the vacuum line from the Turbo Actuator ?

Appears I have now located it at the back right hand side of the engine bay.. lots of pipes and when i check the part number it comes up as boost control valve.. although i think its a very old revision... revision A!!! 

 

So how do i test it? i dont have a vacum pump and cant see a reason to buy one, can i suck or blow through the pipes to test it?

You probably can't test the actual valve that easily, a vacuum tester is your best bet to check the lines. VCDS will probably have an output test for the valve if you have access to diagnostics. 

 

Any problem involving boost control will require a vacuum tester to check for vacuum leaks and measure the vacuum generated. If you suspect the valve your best bet is to try a know good one. That valve will modulate to control the amount of vacuum applied to the actuator.

 

Even a simple visual check of the vacuum lines is a good place to start.

I've 'logged' a similar cry for help elsewhere on this forum, nil response.....I have had the same sort of snags with my Golf for over 6 months. Intermittent blinking glow plug light, limp mode, no power. When I don't get limp mode, I get hesitant/jerky acceleration and rough idle. The lights tend to come on at 70 on the mway. Car in and out of a main VW dealer who hadn't got too much of a clue. The usual suspects (maf, turbo, vacuum, air leaks) all checked, clean bill of health. They charged me over £400 to have the injector loom replaced...didn't fix it. So I got the car back. I have no faith in it and feel I can't take it anywhere.

Until......I took it to an independent out of desperation. First thing he did was change the turbo boost pressure valve. 24 hrs later, it's still running good, with no dodgy symptoms or dashboard lights. He did tell me that should the fault re-occur it's probably a new turbo...or get my one stripped and cleaned.

^^turbo boost pressure sensor replaced, not a valve...

Well ill start with a good look around at all the pipes etc and maybe see if i can drag an old friend round with VCDS to do a scan for me.. in the mean time i have the MAF sensor to clean, new air filter too just incase mine wasnt replaced by the stealers.. and see how i get on... thanks for the advice guys and hope the post helps others too.. 

 

Ill feedback what i find if and when i do..

Dread 

 

I have had many of these symptoms on my PD170 vRS. The hesitancy/stuttering issue just will not go away and has been widely discussed on the forum. I've just cleaned my MAP sensor and induction pipework between intercooler and ASV/EGR. It was pretty badly coated in grey sludgy liquid, which also contaminated the MAP. Not test driven it yet to see if this work has helped.

 

A tame mechanic also suggested unplugging the MAF sensor wires and going for a drive. If the problem goes away then this may be a quick and dirty way to indicate the if MAF is suspect or not. (Fuel economy will go haywire while MAF is unplugged.)

 

Interestingly the stuttering on my car appears if I have been driving like Miss Daisy and less evident when booting it regularly. Recent wet weather also seemed to trigger it, so perhaps an electrical connection issue.

 

The list of things it could be are seemingly endless!

Dread 

 

I have had many of these symptoms on my PD170 vRS. The hesitancy/stuttering issue just will not go away and has been widely discussed on the forum. I've just cleaned my MAP sensor and induction pipework between intercooler and ASV/EGR. It was pretty badly coated in grey sludgy liquid, which also contaminated the MAP. Not test driven it yet to see if this work has helped.

 

A tame mechanic also suggested unplugging the MAF sensor wires and going for a drive. If the problem goes away then this may be a quick and dirty way to indicate the if MAF is suspect or not. (Fuel economy will go haywire while MAF is unplugged.)

 

Interestingly the stuttering on my car appears if I have been driving like Miss Daisy and less evident when booting it regularly. Recent wet weather also seemed to trigger it, so perhaps an electrical connection issue.

 

The list of things it could be are seemingly endless!

 

Hi Excision,

 

I ended up taking off the airbox as i had suspected the airfilter had never been replaced despite being service twice since ive owned it!! and low and behold it was as black as a black thing that was dirty and black!!! so lesson number one, DONT EVER TRUST A FULL SERVICE!!

 

Whilst I was there i used some contact cleaner and cleaned out the MAF sensor and put it all back together nice and clean.. I had a poke around the pipework etc and happened to find that the very pipe you mentioned going to the ASV/EGR was slightly loose on one side (think the mechanic who did my oil change had removed it for access) anyway, popped the pipe back in nice, re-seated the clip and it seems to be staying in place.. on the upside the car feels a lot better now so jury out and we shall see how it behaves over the next few weeks..

 

whilst im here im on the look out for a rear drivers side brake caliper in Red if anyone knows of one going at a decent price???

 

Thanks for the info though, ill keep an eye on it and let you know how i get on!!