As it turns out, one should replace the knitted seal ring that sits between turbo and exhaust pipe when replacing one or the other as it will not seal properly. I have not done so when turbo was still on the table and thus had some quality time removing the old ring in situ. Had to hurt it a lot before it agreed to part with turbo. Below are a couple of pictures comparing new and old. Continue reading Exhaust knitted seal ring before and after
I like measuring things. And I hate loose definitions like “not too much”. How much is not too much? Thus when I decided to check my Garrett T2 turbo before putting it back.
Things to check:
- excess oil in air outlet. Some oil will always be there from breather, but too much might indicate leaking turbo. And that is a small problem which can lead to a large one: engine runaway.
- shaft is turning freely, without noise, sticking, touching anything.
- axial play (forward-backward). For T2 it should be 0.025 – 0.084 mm. I measured it to be roughly 0.07 mm. Such play is virtually unnoticeable by hand.
Axial play measurement. Pull shaft out, zero dial and push it.
- radial play (to sides). Should be 0.056 – 0.127 mm, but can be bit higher as long as vanes are not hitting anything and turning freely. Push axis to one side and use clearance gauge to measure distance to turbo side, then push it to other side and measure again. Difference is the clearance you are looking for.
- wastegate operation. It should move freely.
That’s about it. Please feel free to comment, correct and/or supplement.