"PROBLEM" solved. Bigger diameter of intake manifold reduce air pressure. That is something ECU doesn't like :-) Put original cracked airbox in and changed MAF. All is like before.

For guys with possible air pressure leak. Do the test drive with VAG-COM/VCDS connected. There is range of required air pressure. 3rd gear full load of engine, throttle 100%. Best is find long steep uphill road. There must be boost pressure 1850-2200mbar (1.85-2.2bar). Unsure, what boost pressure is required for vRS version. Don't have a repair manul unfortunatelly.

01 - engine > 08 - measuring blocks > channel 011 and 010 ( I believe channel 010 is for airflow measure, cannot remember.) Use log and then analyse saved log.

Edited 19 May, 201016 yr by sniper29a

what diesel cleaner did you use, please?

just some wynns diesel cleaner mate

I know exactly what it is and it wont show up on any VAG com or diagnostics machine either.

Its your MAF sensor, change it and you will be amazed. £57 exchange on a bosch item from GSF or euro car parts. its nothing to do with your turbo matey

Changed that today, still the same. There is little whirring noise from the turbo, can't find a leak, but if I remove the pipe to the VNT actuator it goes, so as Alleytech says, VNT issue, or could it be the N75 valve not doing it's jobs properly!!!

Changed that today, still the same. There is little whirring noise from the turbo, can't find a leak, but if I remove the pipe to the VNT actuator it goes, so as Alleytech says, VNT issue, or could it be the N75 valve not doing it's jobs properly!!!

start the engine and take off a rubber hose from n75 valve (hose leading to turbo) Even at idle, valve must be open and there will be vacuum if you put finger on the outlet hole of n75.

If you have checked all vacuum hoses, intercooler, air intake hoses. then I am affraid turbo is gone. If you have VAG-COM/VCDS there is test for boost pressure. It will tell you instantly whether your turbo is ok or not. Unsure what is VNT though. Don't know all english words for car parts ;-)

start the engine and take off a rubber hose from n75 valve (hose leading to turbo) Even at idle, valve must be open and there will be vacuum if you put finger on the outlet hole of n75.

If you have checked all vacuum hoses, intercooler, air intake hoses. then I am affraid turbo is gone. If you have VAG-COM/VCDS there is test for boost pressure. It will tell you instantly whether your turbo is ok or not. Unsure what is VNT though. Don't know all english words for car parts ;-)

Just come back home from a run, it was running OK with the exception of the whirring noise from the turbo, performance actually seemed good. Then for no reason turbo dropped out at about 3500rpm. Stop and restarted and all was OK and couldn't get it to do it again!!!! It's really starting to annoy me now!!! :'( Anyone know somewhere local to Northamptonshire I could take it for a good diagnosis?

Just come back home from a run, it was running OK with the exception of the whirring noise from the turbo, performance actually seemed good. Then for no reason turbo dropped out at about 3500rpm. Stop and restarted and all was OK and couldn't get it to do it again!!!! It's really starting to annoy me now!!! :'( Anyone know somewhere local to Northamptonshire I could take it for a good diagnosis?

why do you rev diesel engine so high? I think vRS is like TDi. max torque at 1800-2400. even if you shift gears slowly, max 3000rpm is enough to enjoy max performance out of car. 3500rpm boost drop would be normal since there is steep decline in the boost curve after about 2500rpm. But i am not sure about vRS. I believe it is not that different man. it is just little bit more improved standart fabia 1.9TDi.

forget bloody car services. they are useless. don't forget there is conflict of interest. they want your money and you want car ready. that is something in the conflict. when i purchased my car, there was lots of service history. unfortunatelly, you just pay for a stamp in your service book. Oil and brake fluid change has been carried out a 1 month ago. Guess what, oil is one year old dirty rubbish, brake fluid as well. Why the hell you would use such a service??? Especially, authorised dealers.

buy your diag cable and SW. it will cost you about 150£ and it will pay off very quickly.

http://www.ross-tech.com/vag-com/interfaces.html

check out above by web page. it is ross tech who makes VAG-COM/VCDS. I have recently purchased VCDS LIte due Vista 64bit notebook. Otherwise VAG-COM does well on old laptops. It is enough for me. Does diagnostic and costs about 80£ (100$). I have got diagnostic cable from my country, but you can either buy one from ross-tech or find something on ebay. Ask guys in this forum if they don't know about some cables from UK.

There is two versions of cable. Up to 2004 it is COM cable and anything above by is CAN cables. If you check the link I provided there is explained everything. But watch out for cheap rubbish cables !!!

I am sure some guys may have repair manuals for skoda. I have got only in czech language. If you don't do stupid experiments, nothing can go wrong with diagnostic software.

If there is something wrong, you will see fault codes.

Just noticed you have got 2005 Fabia so you need CAN cable, that newer one.

If you don't find any manuals, I can provide testing procedures for diagnosis of air flow/pressure, boost pressure and so on. It is simply 10min test a and you will know instantly what is most likely wrong.

Just come back home from a run, it was running OK with the exception of the whirring noise from the turbo, performance actually seemed good. Then for no reason turbo dropped out at about 3500rpm. Stop and restarted and all was OK and couldn't get it to do it again!!!! It's really starting to annoy me now!!! :'( Anyone know somewhere local to Northamptonshire I could take it for a good diagnosis?

Classic symptoms of VNT sticking.

Classic symptoms of VNT sticking.

Anyone tried Innotec Turbo cleaner?? Sounds good, but is it???

Anyone tried Innotec Turbo cleaner?? Sounds good, but is it???

any degreaser do in case you take turbo off and clean it by hand. if you want to "clean it" by all these miracle cleaners. I am always suspicious about these on the fly cleaners. They do more damage than help. I am not sure about all technical words of english, but I assume that vanes are these plates which regulate exhaust gases flow thus speed of rotor blades/vanes. And they are not lubricated by engine oil anyway. Only thing lubricated is main shaft with bearings.

take off bottom cover of engine (park your car on the kerb by one side of wheels if you have no lift bay, since there is lack of space ;-) find the turbo and try to move rod, of boost pressure regulation, by hand. also check rubber hose leading from N75 valve. it may be perished and leaking. thus trubo boost regulation doesn't work.

I assume you all know how to drive turbo charged cars. cool down and lubricate turbo before you switch off car 3-5mins after wild ride ;-), don't chase cold car until is properly warmed up (coolant gauge at right temperature is not properly warmed up car ;-) replace oil more often if you abuse your car well.

Edited 22 May, 201016 yr by sniper29a

any degreaser do in case you take turbo off and clean it by hand. if you want to "clean it" by all these miracle cleaners. I am always suspicious about these on the fly cleaners. They do more damage than help. I am not sure about all technical words of english, but I assume that vanes are these plates which regulate exhaust gases flow thus speed of rotor blades/vanes. And they are not lubricated by engine oil anyway. Only thing lubricated is main shaft with bearings.

take off bottom cover of engine (park your car on the kerb by one side of wheels if you have no lift bay, since there is lack of space ;-) find the turbo and try to move rod, of boost pressure regulation, by hand. also check rubber hose leading from N75 valve. it may be perished and leaking. thus trubo boost regulation doesn't work.

I assume you all know how to drive turbo charged cars. cool down and lubricate turbo before you switch off car 3-5mins after wild ride ;-), don't chase cold car until is properly warmed up (coolant gauge at right temperature is not properly warmed up car ;-) replace oil more often if you abuse your car well.

Yep, vanes are the bits in the turbo that direct/regulate gas flow. I have tried moving the rod by hand and it moves freely enough, with no notchiness. There is vacuum on the end of the N75 valve pipe and I do try to remember to warm it up and cool it down properly. :-) I'm guessing that I must have a small boost leak somwhere, still haven't been and bought new pipe seals yet, anyone any idea of the part no's and how many there are???

Thanks for the all the advice and info so far folks!

Yep, vanes are the bits in the turbo that direct/regulate gas flow. I have tried moving the rod by hand and it moves freely enough, with no notchiness. There is vacuum on the end of the N75 valve pipe and I do try to remember to warm it up and cool it down properly. :-) I'm guessing that I must have a small boost leak somwhere, still haven't been and bought new pipe seals yet, anyone any idea of the part no's and how many there are???

Thanks for the all the advice and info so far folks!

I went to auto parts dealer and bought 2m long rubber hose. There are 3 diameters of hoses. When I tried authorised dealer (Seat/Skoda), there is so many hoses and they will charge you fortune for each piece. I have ruptured main vacuum hose from vacuum pump (tandem pump) leading to brake assistant. There is one-way valve which supplies whole vaccum system with air. So start there and follow the pipes.

To put an end to an open thread(which I hi-jacked ), The turbo finally starting making a loud screeching noise like a slipping fan belt and not boosting at all, so I removed it and found the bearing and oil seals had gone, and the compressor wheel had touched the housing, £450 lighter I have now refitted recon turbo and she's going fine. Just need to get a few bits of paint work sorted out and I'll be happy with her now! :yes: Cheers for all the help and advice.

Edited 2 August, 201015 yr by jacko2111