[RESOLVED] Low Boost After 16G Install !!!! Please Help

[ChrisGo]

Just got my 16g installed and took it for a spin and could only boost 10psi I have checked for boost leaks and only get them from the valve cover breather. I adjusted my MBC and no difference. I checked for exhaust leak and i do not see any carbon or any signs of a pre turbo exhaust leak. I bought the turbo used could it be bad? There is very little side to side shaft movement. The only problem i do know exist is a good size oil leak on the return line. Please help me on this i am getting discouraged

 

[kenamond]

I feel as though i have no other boost leak except the valve cover breather. I have fixed the fallowing boost leaks;

TB shaft seals

Bliss screw

Injector seals

BOV

A couple of couplers

I will be ordering a new MBC on Monday.

Also when i did the compression test i let the car warm up to operating temperature, and there was no smoke coming from the flex section of the DP. Then i took it out for a spin to make sure it was good and warm. When i returned it was smoking from the flex section. Also i checked the O2 housing and it was filled with black oily soot and it was brand new when i installed it.

Chris

Don't know whether it's the turbo or the motor spewing the oil unless you can look at something upwind of the turbine and downwind of the motor. Maybe you can drop the turbo from the mani and look for oil in the turbine housing inlet. Or if you can pull the O2 housing off the turbine housing and look for oil in the WG passage. Don't know which is easier.

I'm stumped about the lean condition at cruise, too. As I recall (hoping I'm not mixing info from different threads), you had no boost leaks at the TB. All I could think of is intake valve stem seals leaking air and oil, but that wouldn't make sense if you had no leaks at the TB elbow.

Do you have a logger? If so, log some STFT and LTFT values and post them. I'd guess the lean condition is different than the oil. Might just be a bum O2 sensor, but I'm not too sure.

 

[ChrisGo]

Don't know whether it's the turbo or the motor spewing the oil unless you can look at something upwind of the turbine and downwind of the motor. Maybe you can drop the turbo from the mani and look for oil in the turbine housing inlet. Or if you can pull the O2 housing off the turbine housing and look for oil in the WG passage. Don't know which is easier.

I'm stumped about the lean condition at cruise, too. As I recall (hoping I'm not mixing info from different threads), you had no boost leaks at the TB. All I could think of is intake valve stem seals leaking air and oil, but that wouldn't make sense if you had no leaks at the TB elbow.

Do you have a logger? If so, log some STFT and LTFT values and post them. I'd guess the lean condition is different than the oil. Might just be a bum O2 sensor, but I'm not too sure.

Sorry i do not have a logger.. When i took the exhaust mani off it did not have the oily soot that is in my o2 housing now. I think i will just order a new turbo on Monday. I should of bought a new one to start with I checked and i run 14-15 at cruise is that considered lean?

 

[kenamond]

Sorry i do not have a logger.. When i took the exhaust mani off it did not have the oily soot that is in my o2 housing now. I think i will just order a new turbo on Monday. I should of bought a new one to start with I checked and i run 14-15 at cruise is that considered lean?

You should get 14.7 AFR at cruise (stoich). If the mani had no oil in it, it's gotta be coming from the turbo. Sorry. I still don't know if it's outlandish to rebuild a turbo yourself. If you mark the orientation of the nut on the compressor side, that keeps the rotating assembly the same, and you replace other parts that aren't part of the rotating assembly. I want a not-severely-blown T25 to rebuild for kicks. If it works out, I'll have more confidence in recommending rebuilds to others. Would probably be much cheaper than a new turbo.

 

[ChrisGo]

Well here is a pic of my wastegate flapper.. It is cracked not as bad, but could it cause some of my problems

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[kenamond]

I don't know how big is too big, but I know that these housings crack like that all of the time. When you close the flapper, does it cover the hole or is it offset to one side so that a bit of the hole is still uncovered?

I see that there is no oil in the WG passage. What's the turbine exit look like? If there's oil in the turbine exit but not the WG passage, that's gotta be coming fromt he CHRA. since you have the O2 housing off, you maybe have figured that out already.

 

[ChrisGo]

I don't know how big is too big, but I know that these housings crack like that all of the time. When you close the flapper, does it cover the hole or is it offset to one side so that a bit of the hole is still uncovered?

I see that there is no oil in the WG passage. What's the turbine exit look like? If there's oil in the turbine exit but not the WG passage, that's gotta be coming fromt he CHRA. since you have the O2 housing off, you maybe have figured that out already.

The picture is pre installation, i have no clue what it looks like now.. I bought a new Mitsubishi Evo III Big 16g today and a Hallman MBC.. If the turbo is not the problem then i'll sell it.

 

[ChrisGo]

Well you guy where right the MBC was not working correctly. I installed my Hallman MBC and it boosts perfectly. Now the only issues i have now is it is blowing oil out of the tail pipe under boost and smoke coming from the felx section on my DP. Also i beginning to believe i was duped, because the 16g i got today looks nothing like the one i have. Also i do not remember seeing a serial number on mine. I will take pictures when i get it out. Thanks guys for all your help...

Chris

 

[talon187]

well glad you figured it out. it sounds like the turbo thats on your car has bad seals

 

[kenamond]

If it turns out to be the turbo, keep it and search for rebuild kits. If they're dirt-cheap, rebuild it for the helluvit. Then you have a spare. I'm still not sure if you have to have it rebalanced (read the VFAQ turbo rebuild article, as there are things you have to do to keep it as close to the original balance as possible), and I have no idea how much it would cost to have it balanced, but I'd rebuild my T25 for kicks if the CHRA wasn't shot.

 

[moto x]

Im haveing the same exact problem.

 

[ChrisGo]

Well after it is all said and done i had a bad turbo. This has been a real project and for the record trying to get a good seal on the oil return can be a PITA. I bet i redid it 5 times.. Well i did the boost leak test and now i do not have any boost leaking into my valve cover. I still have the flex section on the DP smoking but i think i comes from getting drenched in oil when my return line messed up. We will wait and see. I would like to thank all you guys for your help..


Chris