Bad Turbo?

[boosted954g63]

When ever I start to build up boost at around 3000-3500rpm with about 3/4 of the throttle and it hits a little under 10lbs of boost, it starts to sputter and it falls on its face and wont let the engine rev any higher. If I take it easy at like 1/2 throttle or less it will run just fine up to what ever RPM with no problems. Mods are in profile and updated. So i am thinking its a bad turbo. What does every one else think?
Thanks Nick

 

[diablos991]

Have you checked the plugs lately? I had the same problem a while back. It ended up being my plugs. Bought noow ones and problem solved.

 

[boosted954g63]

There about a year old. And i recently just checked to see if they were gaped at .028 and they were.

 

[diablos991]

Have you tried a boost leak test?

 

[boosted954g63]

Not yet still gathering suppies for the tester. Well i dont know if this would help but i recently replaced the BOV and there was a huge increase of power when the turbo boosted. It also made my turbo sound alot louder.
Thanks Nick

 

[diablos991]

I would definitely check for boost leaks then. If you have upgraded IC piping, check all of the silicone connectors and the gasket that the Greddy Type-S sits on.

 

[boosted954g63]

No, i dont have hard piping for IC. It is on my list of upgrades to do. But i will definitly do a boost test when i get all the parts and time for it.
Thanks Nick

 

[boosted954g63]

Today my car was acting really weird. It was boosting up to 15lbs and when it started to stutter it will jump up to like 20 for a fration of a second. Just to mention i do not have a Boost controller and it should ber at the stock 10-12lbs. So i dont know how it is geting that high. It sounds to me i got a big boost leak or the turbo going out.
Thanks Nick

 

[napkinthief]

A friend of mine showed me another way to test for a boost leak, but it wont find all the leaks because you have to take the pipe off the turbo. Anyway, turn the car on, let it idle for a few seconds, pull the turbo > intercooler pipe and block it with the palm of your hand. You will have about 5-10 seconds off hissing noise, and that is where your leaks are.

 

[diablos991]

Is it smoking or is there oil in your lower IC pipe or intercooler?

 

[boosted954g63]

I will check tonight when i get home. I remember when i took off the upper IC pipe it had a little bit of of oil in it a while ago.
Thanks Nick

 

[boosted954g63]

Took off the lower IC pipe from the IC and on the inlet where the pipe goes on the IC had oil all around it and inside the pipe had a little bit of oil residue(sp?) in it.
Thanks Nick

Edit: Is the test said by napkinthief true? Will it work?

 

[Talon_BodyMan]

Hey bro my 92 TSi AWD is doing the exact same thing as your car. But I'm pretty sure that it's my wastegate thats bad.

 

[boosted954g63]

Is there any kind of test to check the wastegate?

 

[Mike Marnik]

Is there any kind of test to check the wastegate?

hook a pressure source up to the nipple on the wastegate and see if the arm moves and opens the wategate. Also have you replaced or checked your knock sensor. That would cause power loss problems but not the boost spike problems.

 

[boosted954g63]

No have not checked the knock sensor. When i did a OBD-II reading like 1.5 years ago i did have a knock sensor error though. I will look in to that too and replace it. I heard that they are a pain to replce though.
Thanks Nick