In the meantime check the pipework from the turbo and down/round the drivers side and intercooler. It could be something as daft as a loose connection, or you may find something else obvious.

Will try look at weekend do you have picture of the pipes your talking about please. Im hoping loose connection from using more boost

I don't to hand, the easiest way is to jack the car and take the wheel off. And then follow from the throttle body to intercooler, there's then a connecting piece to the squashed (pancake) pipe behind the wheel, and then follow from rear of pancake pipe up to the turbo. That section is quite a long metal section so check clamps, then there's the charge pipe which is like a 90 degree elbow. Check the bottom of the intake pipe that runs from your maf/airbox as well, it should be secured by a horseshoe shaped springy clip.

Have you noticed any smells in the cab while driving? Cracked manifolds and exhaust downpipe flexi sections aren't exactly unheard of.

Hi guys. Cant get it into garage for smoke test for few weeks due to shift work. I did however do a little test and would like your views. I adjusted the wastegate rod roughly 5mm and now have 16psi boost instead of the 12psi I dropped back to. Still 3-4psi short I know but it holds there so is anybody else thinking its likely to be my wastegate weakened as surely a boost leak would make me drop boost again to 12psi ish..... dont worry I put the wastegate back to the original position

Hi guys. Cant get it into garage for smoke test for few weeks due to shift work. I did however do a little test and would like your views. I adjusted the wastegate rod roughly 5mm and now have 16psi boost instead of the 12psi I dropped back to. Still 3-4psi short I know but it holds there so is anybody else thinking its likely to be my wastegate weakened as surely a boost leak would make me drop boost again to 12psi ish..... dont worry I put the wastegate back to the original position

No smells in cab and flei pipe on sport cat is near perfect

It could well be. Could be that its weakening and can't overcome the pressure as the boost builds towards maximum. It is a little strange that it holds rather than continues to drop but it does sound like that. It could be that the tension is there but the diaphragm inside is perished a little but only shows up top end. Given the position of the actuator it's not uncommon for them to perish, they gather a lot of dust and debris down there. Anyway, it certainly seems a new one is worth a try. Try CR Turbos they sell refurbished oem stock ones around £50.

Cheers mate will give them a call tuesday. Are they easy enough to fit. I take it a new wastegate will have to be set to the right threads???

Yeah take note of the nuts on the one you remove. Leave one nut in place as a marker. You can check it with n75 unplugged for 5psi cracking pressure.

I think I posted earlier in this thread about fitting. It's essentially nuts and bolts but very fiddly. You need the exhaust manifold out the way at the very least, you can probably move the turbo around enough for access with the charge and intake pipes off. The hardest thing is one of the top mani nuts about halfway along, a real b**** for access. A garage who can do it without removing turbo should take 1-2 hours, but it's not the kind of job some want to do as they think you have to take it off. It's doable at home with plenty of time and some good spray for the nuts and bolts, start soaking them a couple days before you tackle it. The manifold nuts themselves aren't too bad mind.

That sounds a right pain my volvo was just undo couple nuts and straight out and swsp lol.... could be a job for a garage next month. Will let you all know if it currs my boost problem

Yeah it would be a lot easier on my Saab too it's at the front, not stuffed down the back of the engine bay. You'd probably manage it but a garage would be less stressful, good luck.

UPDATE: So yesterday had my car smoke tested and nothing was found so the guys at VRS Northampton then boost tested it (no extra charge) and again found nothing so went for a drive whilst plugged in the computer, again (no charge) no fault codes but requested boost was 22psi which is high but either way only boosting 12-14psi. So we still have no idea what it could be. They reckon they can find the fault if I put it on rollers however hat is £120ph and he reckons 2hrs will hopefully be enough time but then I will need to pay for whatever part is faulty and get it fitted so sadly I cant afford that as I now have a wedding to pay for so will now have to leave the poor old girl (car) and start looking again when everything else is paid for.

This also points toward actuator for me as a smoke test wouldn't show up a weak spring I don't think...2 hours of rolling road diagnostics is costly and like you say it's what comes after that as well.

Actuator itself isn't that pricey, it's just the labour to do it. Tricky one. Whether to try that rather than 2 hours diagnostics? Hmm, the diagnostics may be worth it if they definitely find the problem. Did they say anything about the actuator?

No nothing was said about the actuator even though I mentioned it they just said "yeah could be anything on these engines" so non the wiser myself. They did suggest MAF as it does not always throw codes but surely they would have picked that up on computer when road tested. Plus I did the maf test by unplugging it and apart from warning light there was no change still drove the same. The actuator arm is quite easy to move dunno if that means anything

Love that 'could be anything' response, helpful. Think you can rule maf out as you say. I don't think it should be that easy to move. If it were me I'd be exploring the actuator, it's a bit if a gamble but there's pretty good odds. If you google it there was loads of actuator talk on golf and audi forums I found. I did a bit of a pikey mod on mine adding external tension helper springs. It helped a bit, it's a bit dodgy though cause it's all guess work and trial and error.

Didn't you say that cranking on some preload helped? I think there's some pretty strong evidence in that in itself...I wouldn't use that method to correct the fault, but by adding preload to the spring you increase its strength, therefore it signifies a weak spring and/or some perished internals. Weakening actuators aren't uncommon in the 1.8t.

Obviously I can't be certain and I may well be wrong, but I think that's what I'd focus on for the time being.

Yeah i did adjust the nuts and boost went up. Im due back in vag tech on thirsday so will buy wastegate from tps £38 and just ask them to fit it and see what happens. Will let you know

Don't shoot me if I'm wrong lol. Check out the vw forums and stuff in the meantime there was a lot of chat on there.

Will do and thanks again for your help and advise

No worries and by the way congratulations on the impending doom...I mean marriage...take her to the rolling road for a honeymoon, you know, kill 2 birds with 1 stone as they say

Hi mate good news is I am actually getting sorted with wedding bits however not so much luck with the car. Several hours testing on computer and still nothing however just been checking the pipes going to the N249. When I pulled the dipstick out the whole tube came with it as it is completely broken at the bottom.

Question is would this effect boost in anyway through emmissions or any other way???

Hi mate good news is I am actually getting sorted with wedding bits however not so much luck with the car. Several hours testing on computer and still nothing however just been checking the pipes going to the N249. When I pulled the dipstick out the whole tube came with it as it is completely broken at the bottom.

Question is would this effect boost in anyway through emmissions or any other way???

Cars eh? It can cause running issues yes, whether that's entirely responsible remains to be seen but it definitely needs sorting. Good news is it's a cheap, easy replacement. Would also be worth replacing the dipstick itself as the plastic round the top that goes inside the tube can also start to break up. A tighter, newer tube could start finishing that off. Bad news is some bits of plastic will be in your sump, they're usually is lol, just plan for a sump drop and clean up of the strainer on your next oil change.

You can try adding spring on the actuator, that is what I did. But each time I place spring on actuator, I was checking preload with vag-com.

 

At the end, I was able to find spring that is almost fine, boost at high rpm was OK, but preload was 0.2 too high. So what I did is to release bolt on actuator for one turn and preload was down by 0.1. I left it that way for now. I will try to find another spring with better characteristic.

You can try adding spring on the actuator, that is what I did. But each time I place spring on actuator, I was checking preload with vag-com.

 

At the end, I was able to find spring that is almost fine, boost at high rpm was OK, but preload was 0.2 too high. So what I did is to release bolt on actuator for one turn and preload was down by 0.1. I left it that way for now. I will try to find another spring with better characteristic.

I tried that, improved my drop off a little bit, a lot of trial and error involved. Adding too strong a spring is risky.