hi, have you checked for leaking vacum pipes that control the turbo, small hole or cracked rubber joint will give you all sorts of problems, with the work thats been done it does sound like its been lacking power for a while and someone has tried to find it again, has the timing belt been changed latley, one tooth out will cause loss of power to and it may be ready for a new timing belt plus water pump if over 50,000 miles sinse last done.

 

Another possibility is the fuel pressure regulator on the fuel rail, it is maybe jamming and restricting fuel pressure to the injectors. Diesel power comes from fuel pressure at the injectors, all the turbo does it provide more air to burn the available fuel. Does it smoke black or grey under heavy throttle and still not pull, or is it clean and smoke free with no power?

Also can you get the codes read in case you have a fault code stored? As above the vac pipes can be the issue, but you should be thinking along the lines of fuel delivery pressure to the injectors, the rail, fuel filter, etc. A clogged fuel filter will cause low fuel pressure and subsequent codes related to that. I'm sure there is a recall on CDTI fuel pressure regulator, see BBA-Reman site for any recalls or known issues on the CDTI.

Heres a pic of the system: (especially look at items 1, 4 & 6)

 

Right you need a base to start from . Get your codes read by either dealers tech 2 or a Opcom system . Then look at codes those that are followed by not present are old codes you can ignore , those that say present are the codes your interested in so write them codes down . Clear all codes off then drive car till the EML light comes back on then read for codes again and post them on here and we'll take it from there. What you don't want to do is guess at what it might be as you'll end replacing parts that didn't need replacing .

 

I had this same problem on my 1.9cdti Sri 150. Fault code was po246 which suggested wastegate. However I changed fuel filter and hose to EGR valve and power is restored

 

Thanks for all your help guys, Ive got the opcom software coming to me from amazon, soon as it arrives I'll start the investigation.

As for it smoking under hard acceleration I've not notied, just the fact that when you give it some power the sapnner lights up, then when you stop the engine then restart it, its back to normal. I had the same problem with a Golf GTTDI we had and we suspected the turbo actuator. BUT its had a new turbo within the last 6 months - BAFFLED!!!!

Once the OPCOM turns up I'll be straight on here with the codes.

Once again thanks all for the replys, much appreciated

 

no worries mate, hope we get it fixed.

 

hi i have a
3 vectra 1.9 cdti 150 they all went through egr valves between every 10 to 15 thousand miles been told its a common problem with this fuel system have you tried an the BG products i find they work great and my egr valved has gone over 20 with out any problemsBG248 anf BG ISC have been great products simple to use. have a gonwith them worked for me. only a suggestion

 

is that bg10k or something mate? I did hear that stuff was excellent, there was a write up somewhere using a toyota landcruiser diesel engine that had done like 250k or something and it was coked to death, intake the size of a pencil and a cake around the valvetrain that was solid but for a bit the cam was spinning in, it was mad. The BG stuff was used and it really came up clean as a whistle. They cleaned the injectors using diesel magic and it was like a new motor. Might try that stuff myself if I can find it.

 

Thanks for all the replys guys, its just so bloody frustrating, I'm a pretty good hands on mechanic so I know I can sort it, just need to know what it is.
Oh the other thing was the spanner light seems to only come on if you push it, came on at 3500 in 4th this morning, at that point on a 150 you'd expect to be flying.
Think I'm gonna check the vac pipes to turbo in case there is anything un toward, might also clean egr whilst I'm at it.
Is anything ever simple.......

 

could be a boost error, actual vs expected causing limp or fuel cut or something like that? If the turbo is a VNT on the cdti then it may suffer from coking up in the hotwheel end from oily soot. I did a write up on audi-forums or summat on using mr muscle oven cleaner to dissolve it on the car without removing the turbo.

Heres my article: http://www.audi-sport.net/vb/a4-s4-forum-b5-chassis/107121-un-sticking-your-tdi-vnt-turbo-vanes.html

and another copy: http://www.briskoda.net/forums/topi...ic/243533-the-mr-muscle-vnt-turbo-treatment-thought-we-needed-a-guide-of-sorts/

Have a look, it might be the solution.

 

Could this happen even though its a new turbo with less than 1000 miles on it??

 

ah i wouldnt think so mate, i didnt notice that before. ok, well I guess for lack of power you only really have boost leaks, turbo wastegate jammed open, low fuel pressure, wrong injection quantity etc.

I know its not much use to you without a way to test it, maybe an injector is bad etc, but all these things need testing first. You can check for boost leaks with a plumbing cap and a tyre valve & footpump to use the intake hose from the air filter to hold the cap so you can pressurise it and find leaks with a spray of soapy water

Fuel pressure is not easy to test outside a garage tho. Say you nail it in 3rd to get up a hill does it smoke under load or is it clean as a whistle?

 

And all this will show up on opcom(once it arrives)???

 

you can read a load of stuff in these kinda programs, i had rosstech vagcom and it looks very similar so when you know which measuring blocks mean which sensors, you can build up a picture of what is actually happening. I have op-com and a standard lead so gonna try mine too

 

i only use the BG 248 every 10 thousand miles and i have use the BG egr cleaner
once a year the products is good i am about to use an other BG product in my 2002 petrol omega to see if it helps the old bus, she has only done 40k but i have a soft spot for the old omega so i will let you know how it does on petrol car.

 

When you nail it in 3rd under load it gets to about 3500 rpm then the spanner lights up and puts it in reduced power. If you then stop it and switch it back on its back to normal. As I suggested before it could be maf but hopefully I'll sort it once opcom turns up. Did I mention the swirl rod was off too?? Would that couse loss of power if its not operating properly??
Once again thanks for all the replys

 

Put your swirl flap rod back on . Could be lots of things causing your problem . The wife's Corsa 1.7 Cdti had a similar problem to yours it turned out to be a sticking power valve under acceleration unfortunately on her car the valve is integral with the turbo , luckily it was replaced under warranty .

 

yeah man it is critical to low rpm torque and high rpm power but at different settings, long intake path makes best low rpm torque and short intake makes for high end power, its maybe gunked up inside

 

Just a quick update, I'd already replaced the swirl rod when I noticed it had come off, but on the weekend I decided to get a tin of egr cleaner which you spray into the airbox without the filter in. Well when I got in her this morning to go to work, its now got bucket loads more power and most of all, no spanner light!!!!! Explain that one then cos I sure as hell can't.
I'm not gonna hold off getting a new intake though cos I'm pretty sure that could be the route of it and maybe a dodgy maf, speaking of which is still the original one from manufacture - 2005!

 

EGR cleaner works then ! Lol .....

 

Do you spray it in while running? I fancy doing mine too.