Turbo Actuator Arms

Hi im a newbie so please be gentle - purchsaed a 2002 996TT X50 two weeks ago and after a couple of days started to hear a squeal on hard acceleration (and a perceived drop in performance)- initially thought it was a belt slipping - put it into OPC at chester and they diagnosed turbo actuator arms - they declined this on porsche (extended) warranty so have taken it back to garage i got it from and it has gone into Autobahn Porsche independant on Saturday. Their tech has initially test drove it and nopted the sqeal and that it has performance below what is normal for a turbo let alone and X50 and noted boost pressure at 1.5 Bar - which i dont know if that is correct or not. Does anyone have any similar experience please

Hello, I'm new to the forum too, but boost pressure at 1.5 Bar is way way over the top. Standard turbos have boost of 0.7 bar (K16's) but i'm not sure for the X50 turbo's (K24's). I don't think it will be more than 1 bar. If the wastegate (actuator) arms are stuck shut then it will make the turbo's overboost, but i'm not sure the power would drop, I think it would increase with the extra boost. The squeel may be the turbo's being overloaded.

The tech said that if there is an overboost condition then the engine management system would make the engine back off ??- as regards the drop in performance - the car was wheelspinning in second and third gears in damp conditions when I first got it but after the sqeal developed it doesnt do that anymore - I only had the car for a day or so before this happened so cant reallt gauge how much if any of a drop there has been - my last turbo I am sure only boosted to 0.7 Bar? i think so any way

turbo's Hi even on an X50 thats too much, should see about 1.3 bar when nailed and it should keep 1bar constant as opposed to .7-.8bar on a non X50. you have a problem, too much boost is not good to much pressure not enough fuel can lead to major problems so it needs to get sorted. Why did the OPC extended warranty not cover it...??

Re: turbo's Independants technician has found a few fault codes and is adamant the squealing is not from the turbos but the Poly V belt!! He is coming back to me later today about these fault codes Bloody Porsche warranty - they said the actuator arms werent covered as it was wear and tear as opposed to failure - same with the bottom suspension bushes and the dicky seat switch on the drivers seat which sticks sometimes!! - nearly three grands worth of work if I had let them do it - jobs for the boys methinks - heard a few bad things from several different people about OPC Chester so wont be going back there again

Re: turbo's So the best solution is to leave the car in the garage and not use it - hence you would be covered for pretty much any failure. I bet it would still "need a new set of front disks, sir" on the annual service though. :what:

Re: turbo's Yeah think you are right there - been without the car since Saturday and its already driving me mad not having it!

Re: turbo's I don't think your numbers are quite right there. I was quoted, in a number of places, 0.6-0.7 for a standard turbo and 0.8 for an X50. You might get 1.3 if you've been at the tuners for work but definately not on a standard X50. Mine does 0.8 with the pedal planted.

Porsche independant garage have now diagnosed the sqealing as a slack poly v belt - NOT turbo actuators as disgnosed by OPC Chester. - they have also diagnosed the performance problem as a faulty Mass Air Flow Sensor and a boost control valve - none of these being picked up by Porsche Chester!! unbelievable!! have informed OPC Chester and awaiting their reply - better not hold my breath

There have been posts here about the MAF being be covered under warranty - but I expect yours has "worn out, sir".

Re: turbo's

Re: turbo's Something wrong with your's . My X50 car holds a bar , no problem. my old standard 996t held .7 and neither were chipped or tuned.

hey, could you please tell me whether you did get your car sorted in the end and what it was? i have a very similar problem, my 996 turbo is showing 1.5 boost (which i know is not true as the car is slower than standard) and when the car gets to 5000 rpm it cuts the power. i have had the problem diagnosed as air mass meter but that didnt cure the problem. so i have now taken the car to another porsche specialist and he believes it could be wastegate or air leak, etc. any help would be really appreciated.

Hi - yeah mine was succesfully diagnosed as a faulty Mass Air Flow Sensor - but also the boost pressure switch was faulty as well - resulting in the same problem you described - hope you get it sorted mate!