74propu

I have a 5.3 ttb lost all boost psi while I was driving it .checked all the cold side piping for holes none found .checked blow off valve and it sucks air in the dump port when I rev it up .did my dump valve take a dump or do I have something other going on . 25 in vacume at idle

Camaro9969

iTrader: (12)

You boost leak it? Check that first sometimes it's something stupid. Did it just randomly not build boost or were you hammering it and now it won't build?

74propu

pulled out on to the street and steeped down on the go pedal and it fell on its face (no boost) not more then 10 min before that I had boost as I left the doc's office . both turbos have no play in shafts wast gates work freely (internal) checked all cold for holes lose joints nothing found

oscs

iTrader: (19)

It's definetly something stupid. The same thing happened to me a few weeks ago. One of the couplers came loose from one turbo and I couldn't see it. I had to literally put my hands on it to see it had slipped off. Zero boost means you have a massive leak somewhere, keep looking.

LILHEMI

yup. coupler tore or popped off. are you on a maf or speed density?

74propu

I found out tonight lost a turbo took and presser tested all the cold side no leak looked at turbo's again and found one has a lot of play in and out and up and down so I think one is just blowing threw the other dose that make sence I am lost

oscs

iTrader: (19)

When you pressurize the system where does it vent? Can you hear it escaping?

RonSSNova

iTrader: (3)

Makes perfect sense. One not spinning, the boost from the other goes out the dead units compressor inlet.

We didn't know you had twins.

oscs

iTrader: (19)

I agree with this. He should be hearing it rush out of the inlet though. It should clear as daylight.

74propu

I could hear it but could not find where it was coming from now I need to find a better set of twins to put on it that I can afford with internal wastgate

oscs

iTrader: (19)

Verify before you do anything. Get a peice of wood or something flat to cover up the inlet of the turbo. Do that and verify it is escaping from there.

pyro719

iTrader: (5)

Put your bt on the turbo inlet.

74propu

ok treat me like I am dumb because I am what the hell is a bt and why would I put it on the inlet

JoeNova

Have you verified that one isn't spinning when it's running? Are there any marks on the inlet where they wheel may have contacted it?

LILHEMI

BT= boost tester you pressurize the whole system this way.

oscs

iTrader: (19)

You already have a way to pressurize your system. Just cap off the inlet of your suspect turbo and verify where the pressure is escaping.

pyro719

iTrader: (5)

This. You will need to make a cap also since you are twin turbo.

74propu

pulled apart the turbo in ???? the compressor case is all ate up whe the wheel has been hitting the case and the blades are all wore off

stevieturbo

you found the problem then.

JoeNova

Precision turbos?