# Symptoms of bad wastegate actuator



## Trbogti222 (Dec 11, 2012)

I have a 2004 Gti 1.8T with a gt28rs that is internally wastegated. I was getting on it hard the other day to merge onto the interstate, when all of a sudden the car just fell on it's face, lost all boost, and began sputtering real bad. I thought i had went lean and melted a piston but i later concluded that it was just my water/methanol injection and a very rich condition present when the car lost boost. Once it "cleared out" all of the methanol and fuel it ran/idled as normal with the exception that it absolutely would not build boost past 2psi. It is like you hit a brick wall, it WILL NOT go past 2psi. So naturally i though i had blown an IC pipe coupler off. Upon inspection, everything was tight as it should be. Also when you rev it out, you can't hear a "rushing wind" sound like you can when a hose blows off, just a very faint whistle. Now at rest, I can open my dump tube and rev it and you can definitely hear that the turbo is spinning like it normally does when at rest. The WG actuator is controlled by a MBC by the way, the n75 is connected electronically only. So if the IC piping is all secure and the turbo is spinning at rest, and since it only makes a really weak sounding whistle under load and will only hit 2psi, I'm thinking it almost has to be the WG actuator. What i don't know is, if a WG actuator fails, would it cause the WG to be stuck open, or stuck closed?? Mine acts like it is stuck open. I can physically pull on the actuator rod (it requires a good bit of force), and it will move. I'm just not sure if the WG is normally closed and the actuator pulls it open, or if the WG is normally open and the actuator pulls it closed. It's too much of a headache to remove my downpipe to see what state it's in. Surely someone knows or can shed some light on this issue. Thank you in advanced for the replies.


----------



## FatAce (Jan 30, 2012)

BUMP to this, I am having similar issues.  After chipping my stock k03s, it ran about 20 lbs (23 requested) from the start which eventually went to 18, then one day after hard acceleration my boost just dropped off to around 3-5 lbs. I ran logs under full boost and the n75 is operating at 95% under WOT. I believe that is fully open and is not the cause of the issue. If anyone can shed some light on this issue I would greatly appreciate it. I am going to try mad max's wastegate spring mod and I will return back with my results.


----------



## tractorsosa (Aug 19, 2009)

long time ago, something similar happened to me, i was not able to see boost at all, and ended up be my wg actuator stuck open due to a falling lock nut, check them it wont hurt to do it


----------



## FatAce (Jan 30, 2012)

threw a spring on there as per the mad max mod and saw a slight increase in pressure. I gave in and pulled the trigger on an f23. I know its a little overkill for a faulty wastegate but the funds were there so it had to be done.


----------

