LB7: Did I blow my turbo?

[05lly2500hd]

no codes?

You'd be surprised how a torn/cut boot would do this. You can't really see it either unless you squeeze the boot or take it off and inspect.

 

[dmaxfireman]

pressure test would be the best way to start

 

[Sandracer799]

no codes?

You'd be surprised how a torn/cut boot would do this. You can't really see it either unless you squeeze the boot or take it off and inspect.

I got a MAF code but I am pretty sure that is because I started the truck without the intake on.

 

[Sandracer799]

pressure test would be the best way to start

I am going to try and pressure test it tommorow. I also borrow my buddies long bore scope so I can look up the down pipe and see if maybe the door on the wastegate has come off.

 

[Mike_S]

Don't forget the other side of the turbo...it takes exhaust pressure to drive the turbocharger. Look for any soot at any of the pre-turbo exhaust connections. Also, list ALL the codes you have retrieved from the ECM, sometimes these trucks go into a form of limp mode, but don't ignite the check engine light.

 

[05lly2500hd]

is the MAF sensor installed at all? may sound weird but it will do some funny stuff. I installed mine backwards by accident and it made NO boost at all, and black smoked like hell.

Pressure test is pretty simple, get a plumbing end cap from lowe's that will fit over intake pipe tightly, drill the center of it out and tap in a fitting for an air compressor hook up, put 20 pounds or so on it, spray water/soap around every connection. Leave engine off, have someone regulate boost and you look around and LISTEN. Took me 5 seconds and I found a hole in my intercooler.

 

[05lly2500hd]

Don't forget the other side of the turbo...it takes exhaust pressure to drive the turbocharger. Look for any soot at any of the pre-turbo exhaust connections. Also, list ALL the codes you have retrieved from the ECM, sometimes these trucks go into a form of limp mode, but don't ignite the check engine light.

yeah, like around the manifold to uppipe connections, egr connection, uppipe "bellows" etc.

If I would have taken that job in SC, I'd stop by and give you a hand. sorry.

 

[Sandracer799]

The only code I got was a P0102. I cleaned the MAF and cleared the code. Still doing the same thing.

I am trying to pressure test the system now. This is how I have it hooked up.

Should it be holding the 20psi? Or just pushing the air through the system?

 

[dmaxfireman]

should be holding pressure after you block the air filter because you should never have an intake and exhaust valve open in the same cyl at the same time. maybe a tad of blowby past the rings but minimal at most

 

[dmaxfireman]

is the MAF sensor installed at all? may sound weird but it will do some funny stuff. I installed mine backwards by accident and it made NO boost at all, and black smoked like hell.

Pressure test is pretty simple, get a plumbing end cap from lowe's that will fit over intake pipe tightly, drill the center of it out and tap in a fitting for an air compressor hook up, put 20 pounds or so on it, spray water/soap around every connection. Leave engine off, have someone regulate boost and you look around and LISTEN. Took me 5 seconds and I found a hole in my intercooler.

his maf sensor will not stop him form building boost becuase he has an ihi turbo not the vvt that you have. only the wastegate can 'control/limit' boost on an lb7

 

[Sandracer799]

It is not holdinig pressure at all. I hear something up towards the turbo. The gasket around the intake horn looked like it was leaking a little bit so I have a new gasket to put on there. But as small as a leak it was I would think I would have gotten some boost. I am still thinking that the door to the wastegate has fallen off possibly.

 

[dmaxfireman]

have you tried driving the truck since you popped the wastegate back shut?

 

[Sandracer799]

I never popped it back shut. I am assuming now that it is in the shut position. I just checked to make sure it was still moving. I have tried to boost it up in 4wd to see if I can get any boost and I can not get any at all.

 

[dmaxfireman]

gotcha, thought you said it was stuck open for some reason. could be a blown intake gasket at the y bridge or intake runner as well if you hear a leak by the turbo

 

[Mike_S]

his maf sensor will not stop him form building boost becuase he has an ihi turbo not the vvt that you have. only the wastegate can 'control/limit' boost on an lb7

Not true. The MAF sensor has alot to do with fueling in all of the duramaxs. If the MAF is defective or not reading correctly the ECM will limit fueling. You will not get full throttle this way.

 

[Mike_S]

The wastegate itself will not cause an issue in the pressure test that you are performing. It will be isolated by the exhaust valves. Do you get excessive amounts of smoke when you are at full throttle? I am beginning to think that you have a bad MAF sensor. Cleaning them doesn't always fix them...

 

[Sandracer799]

The wastegate itself will not cause an issue in the pressure test that you are performing. It will be isolated by the exhaust valves. Do you get excessive amounts of smoke when you are at full throttle? I am beginning to think that you have a bad MAF sensor. Cleaning them doesn't always fix them...

Yes I am getting alot of smoke under full throttle. The thing is this all happened over night. Drove the truck home one evening just fine. Next morning this is happening.

 

[dmaxfireman]

hey mike, read his original post then re-read yours....

he is pouring smoke and not building ANY boost on a fixed geometry charger, if his fueling was limited he would not be pouring out smoke. This is a physical / mechanical problem not an electronic problem.

 

[Mike_S]

Well let him tell me that, and don't jump down my throught. Just trying to help...guess I'll stop cause it just pisses guys off. Merry christmas hope you figure it out I'm done helpin.

 

[Dan@PPE]

I bet the flapper (the part that opens and closes inside the turbine housing) for the wastegate is gone....