Bad turbo

[thoward]

How free should turbo find be? I was checking my turbos and there is a discernable difference in how free one turbo feels, when spun by fingers, compared to another. Can you tell if a turbo is about to go bad?

 

[rsmith]

If the bearings are bad the shaft will wobble. If its stiff the oil in it is probably coked.Ive seen guys plug the oil scavenge lines and fill with marvel mystery oil. then let it soak for a while. remember the thing spins like 50,000 . Ive seen pics where they grenaded. Not something to mess with if your not sure wat's up with it.

 

[bobk]

If the bearings are bad the shaft will wobble. If its stiff the oil in it is probably coked.Ive seen guys plug the oil scavenge lines and fill with marvel mystery oil. then let it soak for a while. remember the thing spins like 50,000 . Ive seen pics where they grenaded. Not something to mess with if your not sure wat's up with it.

What causes the oil to coke?

Bobk

 

[Genesis]

Shutting it down hot.

Don't do that.

For the dry turbos the only cooling they get is the oil flow. Remember that the exhaust side runs in excess of 1000F under load. The metal mass takes times to cool down and the only thing to take that heat away is the oil.

So when you intend to shut down come off the power and let the engine idle for a few minutes (if you have EGT gauges watch those) out of gear before you shut down. Your turbos will thank you for this.

Hot shutdowns, especially hot shutdowns from a loaded condition, should be considered an emergency action where you're willing to risk sacrificing the turbo(s) involved.

 

[thoward]

Major disaster averted, I think. We ended up pulling the turbo to find a small leak in the riser which caused corrosion of the turbo flange which, in turn, was catching the turbo blades. I am taking both turbos to be serviced/replaced. Now I just have to figure out what to do with the riser issue.

 

[rsmith]

Major disaster averted, I think. We ended up pulling the turbo to find a small leak in the riser which caused corrosion of the turbo flange which, in turn, was catching the turbo blades. I am taking both turbos to be serviced/replaced. Now I just have to figure out what to do with the riser issue.

A friend of mine bought a 55 Ocean with 8/92's and had the same problem. the cracked riser was spraying water into the turbine blades and eroded them. Even tho the engines surveyed ok aparently that engine was overheated and caused the crack. Since it is a wet liner engine he stated showing water in the oil and found the liners were leaking too. It be worth keeping a close eye on that engine.

 

[67hat34c]

Manipulate the riser, first you may want to use ultrasound and hot packs.