[RIQUE]

Hello Turbo Friends,



As adviced by several of you I decided to take a good look at my turbo so I disassembled the bike to the point where I can see both turbines and waste gate.

The fans rotate smoothly on both sides with no wobble or noticable resistance. However, the waste gate does show a problem. From the pictures you can see

that the valve its self is loose on its arm. When I open the arm I can wobble the valve with my fingers. I don't know if this is how its supposed to be

or if the valve has come loose. Your input as always is appreciated.

 

[81custom]

doesn't the arm move forward - not backward ? so the arm pivots on the rod and pushes the valve open?

 

[RIQUE]

You'r looking at the valve closed. But when I moved the arm towards me to open the valve, the valve dangles on the arm.

 

[ishootstuff]

I think you found the problem. I'm not 100% sure, but I don't think that should be loose at all, however, what does it look like when you are not opening the wastegate with that wrench? Mine has no gap.

 

[RIQUE]

Lex, the bottom picture shows the gate closed. It sits pretty tight but you see the gap between the plate and the valve? . Maybe its like that I don't know. Did your gate move around on the plate or was it fixed solid?

 

[timothy_d]

I don't remember my 650's turbocharger having a loose, floppy valve.



Oh, what the hell am I thinking??? (idjit), I have two turbochargers in my kitchen.

I'll put a reminder on my phone to look at them tonight.

 

[RIQUE]

Tim, I will greatly appreciate your reply. Let me know how the valve is held onto the supporting arm. pic maybe

 

[ishootstuff]

I just bought one as a spare, so I can check that out too when it arrives. Ironically and totally unrelated, I also bought a new turbo for my Lexus. Did you know running to lean can melt the turbine?

 

[RIQUE]

I just check the axial play of the turbo and its pretty bad. I understand turbo fans should have zero play right?

 

[timothy_d]

Not entirely true.



Turbos should have no lateral play (intake side to exhaust side wiggle across the length of the turbocharger).

However, there will be a tiny bit of wiggle in the bearings. This wiggle room is where the oil flows.

After a fresh rebuild with brand new bearings, I had just the slightest hint of wiggle in the bearings.

Excessive wiggle, bad. Barely noticeable wiggle, okay.



It is more important that the turbocharger shaft be balanced. An out-of-balance shaft can kill a turbocharger very rapidly.

 

[timothy_d]

Okay, I looked at my spare 500 turbocharger last night. There is a gap. \

About enough to put a fingernail through and wiggle.



Based on how the actuator works, this is not a problem.

 

[edinlr]

I just bought one as a spare, so I can check that out too when it arrives. Ironically and totally unrelated, I also bought a new turbo for my Lexus. Did you know running to lean can melt the turbine?

I guess that is possible. In most cases you will hole a piston or the ring lands will collapse. It is hard to imagine a case where the pistons would survive long enough for the turbine to fail. The combustion chamber gets much hotter than the turbo, so a lean condition should do much more damage there. Most turbines fail due to oiling issues from either trash in the oil, or just lubrication problems. A part that is designed to spin to 200,000 rpm is much more sensitive to lubrication than something spinning at 9,000 rpm.

 

[ishootstuff]

I guess that is possible. In most cases you will hole a piston or the ring lands will collapse. It is hard to imagine a case where the pistons would survive long enough for the turbine to fail. The combustion chamber gets much hotter than the turbo, so a lean condition should do much more damage there. Most turbines fail due to oiling issues from either trash in the oil, or just lubrication problems. A part that is designed to spin to 200,000 rpm is much more sensitive to lubrication than something spinning at 9,000 rpm.

It wasn't the turbine shaft, it was the turbine fins, and the Toyota 2JZ motor is famous for its strength in stock form. (sorry for the hijack)

 

[RIQUE]

Not entirely true.



Turbos should have no lateral play (intake side to exhaust side wiggle across the length of the turbocharger).

However, there will be a tiny bit of wiggle in the bearings. This wiggle room is where the oil flows.

After a fresh rebuild with brand new bearings, I had just the slightest hint of wiggle in the bearings.

Excessive wiggle, bad. Barely noticeable wiggle, okay.



It is more important that the turbocharger shaft be balanced. An out-of-balance shaft can kill a turbocharger very rapidly.

I got a rebuild kit for the IHI turbo and it states in the instructions that if fins and shaft are removed and replaced in exact same position

balancing is not required. If you move them out of place your' screwd.

 

[timothy_d]

That is correct.

 

[ishootstuff]

Got the spare turbo today. It's just like your picture where the wastegate flap has some play in it. However, it is MUCH cleaner than yours and so is the one installed on my bike.