Almighty Wez

iTrader: (22)

I've been trying in vain over the last few days to figure out why my car is only running 10#. Tried all the usual subjects, WG act, MBC, boost leaks etc but nothing has worked. So the last possiblity is the turbo. I took it off last night to check it out but didn't notice and major shaft play or anything out of the ordinary. Has anyone else had their stock turbo go for no reason?? I don't notice any smoke while driving or under boost but it is overly laggy now. I'm going to take it to the dealer next week and hope they will replace it under warrenty.

gsujeff55

iTrader: (4)

did you rescently change any piping or anything? how did you check for boost leaks? any mods right before this started happening?

i doubt very seriously its the turbo.

Gabriel J

iTrader: (21)

Better put everything back to stock...Otherwise you'll be paying for them to check everything you listed in your post to see if that's truly the issue.

Could a turbo fail at 20k? Sure...It's not very likely unless you had an issue with cooling/lubrication. A damaged blade would be visable and audibly noticeable...Check everything 2 more times to see if you missed anything.

GOKOU

iTrader: (2)

I bet :MIT will void your warranty for taking the turbo off calling it an improper removal. Good luck.

It may be that you miss the small tests such as boost leak, compression test, spark plug change, etc.

MalibuJack

iTrader: (5)

I doubt its the turbo, but you may have a problem with your wastegate actuator, it could be damaged or the seal is leaking.. If the MBC is stuck it could stay at wastegate pressure which is 10.5-16psi (Depending on which restrictors are still there and whatnot.

MalibuJack

iTrader: (5)

FWIW make sure the wastegate nipple isn't bent or crushed.. It could impede the flow of boost into it but that could result in spiking and not a low boost.. but if the wastegate actuator is binding or jammed, it may not be closing the flapper all the way

Almighty Wez

iTrader: (22)

I actually just replaced the WG act. with another one and it didn't fix the problem. Intake tested it to 25#, no leaks. Haven't changed any piping, the car is 100% stock under the hood. Took off the MBC and put all the stock lines back, no change, same when I put the stock BOV back on. The turbo is the only thing left that could be causing the problem. A friend of mine has a hookup at a local dealer so hopefully they'll just replaced it, or at least take it in and figure out what it is under warrenty.

sophis

iTrader: (7)

Is the car stumbling when trying to reach 10 psi or does it just pull normally to 10 psi and stop there?

EVO3675

Try removing the 02 housing and see if the flapervalve is just stuck open or maybe jamed

Almighty Wez

iTrader: (22)

The car pulls smooth to 10# then stays there. I did check out the wastegate itself when I had the turbo off and everything looked fine.

RyanM

iTrader: (1)

How far down did you push the vacuum tubing on the turbo fittings? Not sure what you have for play, but I'd push as much of it onto that nipple as possible and probably double zip tie it to be sure.

The stock lines might not be a valid test because if you didn't reinstall that T-fitting that came with the car then your only going to boost 10lbs.

Usually when turbos die they don't reset to the built in waste gate actuators release pressure. There's also usually crunching, grinding and somtimes fire.



At the very least, there is usually a rattle

Almighty Wez

iTrader: (22)

I made sure all the vac lines were on tight, none had blown off or anything. The nipple on the wg act. isn't bent or crimped in anyway.

mrbkkt1

iTrader: (6)

any cel or real bad fuel milage?

MalibuJack

iTrader: (5)

Well, wastegate pressue on the spring is around 10-12# depending on the preload adjustment, basically if you have a signal going to the wastegate actuator it will go to 10psi approx and stay there..

This indicates to me that your MBC is not adjusted correctly or its stuck completely open.. if you bypass it and loop a vacuum source to the actuator it should do the exact same thing.. Try a different MBC and verify its not hooked up backwards (though I don't know hooking up backwards would do anything or massively overboost)

What kind of MBC is it again? Oh, and putting the stock lines back on will work **IF** you didnt lose any of the restrictors and you put the lines on correctly..

If you feel the hoses, there are 2 restrictors, one about 3" from the end of the long hose, that goes to the solenoid, the other restrictor is in the shorter line, which goes to your vacuum source.. IF ITS HOOKED UP BACKWARD or you replaced the short line with a longer line and removed that restrictor, it WILL NOT BOOST OVER 10PSI

gsujeff55

iTrader: (4)

best way to check if it is your turbo, or wastegate is to take the vac line off of the actuator completely. Slowly get up to speed and get in a higher gear(atleast 3rd) and get on the throttle slightly and watch the boost rise. if its your turbo or wastegate, the turbo will only boost 10psi....if its not, it should run on up. BUT BE CAREFULL, do not stomp it by any means, it will spike to 30psi or so and possibly hurt something. Just slightly get on the throttle till you see 20psi then putt back home out of boost.

Then you will no where to look, but probably something to do with your hoses or MBC