Lmm boost leak or up pipe leak?

[Rancelot211]

Just installed a built trans and Danville 3794. Having problems with smoke and egts. Pressure tested the system and found no leaks. Any help?

 

[onebaddmaxxx]

Up pipe leak would probably be noticeable. Black soot under the hood, squealing, etc.

Are you making any boost at WOT?

 

[Rancelot211]

Yes makes good boost. Lots of smoke when tc is locked in 6th egts high whenever you hit the skinny pedal. Same about of fuel as being I changed charger. Crusing the egts are in check though. Goes into reduced engine power from under/ over boost when it's cold. But no codes stored.

 

[Rancelot211]

Anything guys? Goes into reduced power on cold start and fine after I clear it. Turbo vanes go to 100% when the reduced message comes on..

 

[gmduramax]

Who's tuning?

 

[Rancelot211]

Kory Willis Ppei. He's certain its a boost leak but can't find one

 

[BLACKMAX1]

So your tuning is updated for the new charger? Are the boost levels erratic, when you pressure tested the system did you do it from the hot side leaving the charger?

 

[Rancelot211]

Boost seems normal but going off the factory sensor from my cts. Did it before and after the new tunes for the charger. I put the tester in the I/c pipe coming off the turbo on drivers side of truck.

 

[BLACKMAX1]

Yea I'm betting there's a leak at your uppipes, are you sure they are tightened evenly and you didn't drop or miss a gasket?

 

[Rancelot211]

Used a torque wrench. Gaskets are In there. Can't really hear an exhaust leak.

 

[BLACKMAX1]

Did you hold pressure in the system, and how much did you put in there? Could be a hole in a boot or air pushing past the clamps. Other than that I'm at a loss. what's blocking your egr port?

 

[Rancelot211]

Held 20 in there. Egr riser is welded.

 

[BLACKMAX1]

Alright I'm lost.

 

[NAFLASH]

Hole in the intercooler? Wouldn't be the first time I've seen it.

 

[clrussell]

Stock y bridge?

 

[Rancelot211]

No hole and stock y bridge with a profab strap.

 

[Rancelot211]

What's the best way to test the up pipes and gaskets? I have access to a smoke machine. It that would work?

 

[Rancelot211]

No hole stock y bridge with a profab strap

 

[Bonestock]

Stock y bridge?

More often than not on the two piece Y bridges LBZ and LMM the Orings won't hold much boost. Thats where I would be looking. Pressure up the system. YOu can start low 10psi and increase as needed to hear / feel the leak if there is one. Good luck, I went thru this more than once with a LMM and it was the bridge. I have a tig welded one if you need it.

 

[Rancelot211]

Alright will look into it tonight. How much for the bridge you have if that's it?