Just pulled out to overtake a few cars sitting behind the bus (doing less than 50) Dropped a gear and boosted passed, just as I got alongside the bus I lost power. Just coasted passed and then pulled in about 500 yards up the road. No warning light. But drove it to my mates garage (wouldnt go passed 3000rpm in any gear and had a bit of a misfire) First time read there was no codes. So my mechanic took it for a blast - then the CEL light came on - read the codes and it came back as a17965:- Positive deviation. We chacked all the boost pipes, all hold their pressure on the boost tester he has. The actuator moves with the N75. And with the egr disabled its still the same. Could it be stuck vaines on the Garrett? Its an ASZ PD130 - still on its original turbo with 106K on the clock. It is mapped, but its been fine for almost 22,000 miles.

Any ideas or is it going to get expensive quickly?

You sure the actuator is holding vacuum?

Swap your N75 with your EGR solenoid to rule that out as a cause.

Past that point, it's turbo off and make sure your exhaust end of the turbo is clean... Some people use Mr Muscle, others have it apart and clean it.

Could also be your MAF... Or your MAP sensor...

Probable causes for code 17965 (turbocharge pressure - control limit exceeded) are:

- hose connection interchanged / not connected

- turbocharger boost pressure sensor

- turbocharger wastegaste regulating valve

Hope this helps.

SN

Checked all the boost pipes - no leakes

Checked the N75 & EGR - both doing as they should

Wastegate is opening and closing with the actuator.

I switched the car off for an hour while I washed it in a ****ed off mood. By the time I had gone back to it the CEL light had gone out and I've now got power again - so I tried my hardest to make it do it as hard as I could (with several different driving style - brisk acceleration upto 5000rpm in 3rd. Mid range 5th gear over take. 6th Gear cruising at motorway speed uphill - then put your foot to the floor on the climb) I couldnt make it do it again!!!

Garage I use is pretty good - he first thought the wastegate vacuum hose. but its fine and he has pressure tested the whole system. Then he said down to the age of the turbo he thinks the vanes have stuck open and the ecu has thrown up a safe mode to stop the turbo damaging the engine.

So what are the chances that just a good clean with Innotec Turbo Cleaner may fix it? Or should I start looking for another turbo?

Could be sticky vanes.

Do you have or have access to vcds? If so log group 11 from 2k to 4.5k. Same the log and open in excel. Best putting the data into a line graph. Then you can see request vs actual boost. If its the vanes or simply too much fuel it will over boost.

I think just sticky vanes. They do that, and a good Italian tune up like you did when in your ****ed off mood, might have de-coked the vanes a bit. Might be worth whipping the car on a ramp and removing both sides of the turbo, i.e downpipe and intake pipe, and spray some mr muscle oven cleaner in there. Should clean up the vanes a treat.

really?? Mr Muscle??

mr muscle mr muscle mr muscle. silicone pipe down the egr hole. Done 7 so far and one has done 20k since with no issues. costs £2.99

aye - the foaming stuff. You should see what it does to the carbons on the inside of your oven, so the carbons sticking to your turbo vanes (and the turbo in general I guess) won't stand a chance.

Obviously if you can remove / disassemble / clean/mr muscle the gubbins / reassemble / refit the turbo, it would be better, but its a good temp solution whilst leaving the turbo bolted up.

its really good, and it is permanent in my eyes, 2 hours in the turbo (i use this time to rebuild) then let her warm up and blast the crap out on a dual carraigeway

its really good, and it is permanent in my eyes, 2 hours in the turbo (i use this time to rebuild) then let her warm up and blast the crap out on a dual carraigeway

Probably works in only 15 minutes. That's roughly how long it says to leave it in the oven before wiping/washing.

I bet you could blow it in and by the time you've bolted on the downpipe and intake pipe again, you can go right out.

haha probably, but i find that little bit longer just gives the peace of mind. Done it with a4's passats and octys and fabias. So many in fact i have got elbows that fit on top o the can without the nozzle and lengths of silicone tube so i dont have to mess with pliers, on mine i squirted it in and within 10 seconds i heard my actuater pop free, everytime i pumped the actuater during the 2 hours it seemed smoother, at 2 hours it got no better.

Anyone fancy explaining the mr muscle thingymanob a bit more?

And the method or methods to do said fix?

a how to would helpful please

Spray it in, leave it a bit, go for a drive to blow it out the system. Job done.

ill find the link hold on

here it is:

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

Edited 5 July, 201213 yr by Lofty79

I think just sticky vanes. They do that, and a good Italian tune up like you did when in your ****ed off mood, might have de-coked the vanes a bit. Might be worth whipping the car on a ramp and removing both sides of the turbo, i.e downpipe and intake pipe, and spray some mr muscle oven cleaner in there. Should clean up the vanes a treat.

just a clarification (VERY IMPORTANT) ONLY do the exhaust side with mr muscle!!!!! It is sodium hydroxide and very aggressive to alluminium (which the intake side is made of)

You probably meant this but just in case i thought id better clarify. Great solution though as garages told me new turbo when i had the issue

I'm a little stuck then as I have no access to a ramp - as i'm meant to be away on a 1000 miles drive this weekend in the fabia! I was giving it some on the way to work this morning - but no issues (no i wasnt speeding, I was holding onto the revs higher up the range in lower gears and seeing if it would do anything and putting my foot to the floor in 6th at 50mph to see what would happen under extreme loading) I've also put in about 1/4 a bottle of millers!

Anyway to get the Mr Muscle Mod done this evening??

It can be pretty quick if you just remove the egr pipe (or blanking plate if you have EGR delete) and use a silicone hose or similar to squirt into turbo.

You then leave it a bit then take it for a drive to blast the stuff out the turbo and through exhaust.

Phil

cool! I'll get some of mr Muscles finest and get it done later! Fingers crossed it works!

While you're in there check all your vacuum pipes especially the one to the turbo. They can sometimes crack and look ok but actually leak.

Phil

We did a vacuum test on the whole system lastnight - no leaks

Oh yes. Of course. You did say!

Just reach around the back of the engine and do it by feel. Follow instructions in that link. It WILL work, make sure pipe goes down to turbo not into a pot, but its hard to get wrong. Takes me half hour to do job and then 1.5hrs waiting, firming that time pump actuated up and down periodically.