BC847

In taking things apart for another project, I pulled the HX35 Hybrid off and set it on the floor, resting on the exhaust housings outlet. I went back the next day to look at the turbine for something and found a couple of drops of engine oil hanging from the turbine's shaft.

I guess I've toasted the turbine-side shaft oil seal.

I've ruined a perfectly good turbocharger in the past by not letting things cool off before so I know that's not a contributing factor here. I've since always let it cool to about 350*F before shutdown. Further, I'm running synthetic oil so 350* is really a little low in that regard.
I've no indication of any bearing issues.

Anybody ever replace an oil seal on one of these things? I had hoped to sell the thing as a good used unit rather than a fancy core.


Any suggestions?

B-North

There are lots of rebuild kits available online. I have seen many people rebuild holsets just marking the wheels in relation to the shaft and not rebalancing the rotating assembly. They have lasted just fine. I say dig into it and DIY then post a nice how-to. If it's anywhere close to as informative as your trans thread it will be much appreciated.

bgilbert

You should store turbo's in the upright position, that is, the way they are positioned on the engine. If not you can get some oil leakage like you have experienced.

Boatnik

I rebuilt my H1C/HTT Stage 4 turbo last year. Once I got the center section out on the bench it was a breeze. Having a small lathe to lightly polish the shaft made it real easy. The seals on mine look like small piston rings from a model airplane engine.

CaptainChrysler

I have had this happen to me as well. I would not worry about it. Like Boatnik said the seal is like a piston ring, it is made out of steel. It will only be oil tight while running on the engine, or at least sitting like it is.

BearKiller

For what it is worth, I will relate my little knowledge about turbo seals.

Not yet with any of our Cummins (never---I hope), but with other turbo-charged diesel engines, my experiences have been that a leaking turbo seal will spit raw engine oil into the exhaust, WORSE --- MUCH WORSE --- when at a slow idle, and then pretty much drying up and hardly leaking at all at speed.

Also much worse when the engine is cold; the oil dripping from the exhaust-pipe will be thick and very sticky, just like you stuck your finger in a can of STP .

This condition will make itself very evident in vehicles that do not have any type of exhaust restrictions, such as a muffler, and that have an exhaust system that is pretty much all down hill from the turbo, such as the short turned down exhaust found on many dump-trucks.

With such an exhaust system, you can actually watch the raw engine oil DRIP --- DRIP --- DRIP --- out the pipe as the engine idles.

The first time I witnessed this was after a big snow.

The truck I was driving had a big hole in the bottom of one of the stack elbows and raw oil was steadily dripping out that hole, making a very noticable mess in the pretty white snow.

Had the exhaust been in A-ONE shape, with no big hole in the elbow, the oil would have stayed captured in the exhaust until such time that it became hot enough to vaporize, thus the hazing.

With a muffler, the hazing is much more pronounced, as the raw oil never actually gets hot enough to go anywhere; it just keeps simmering as the muffler gets fuller.

BC847

Thanks for the replies folks.

I've never been into one so I wouldn't know about them. But I must say I've never noticed mine leaking as such when I've had them on the floor. Certainly it smokes as though it were leaking oil somewhere at idle. Bringing the engine up to a very high idle changes nothing immediately (oil in hot-pipes?). I'm replacing it so it's not mission critical.

I hope that's what it is.

I've still got to pull the injectors to see how they look. For what it's worth, I don't see any differences in the exhaust ports of the head (wet).

Thanks again guys.

BC847

Well, so the injectors are out and look OK.

- Pulled the delivery valves, took them apart and found two with shards of rubber (fuel solenoid) wedged in them.
- Got all the ceramic coated stuff back today.
- Need to retorque the studs. Uhg!

My truck came stock/OEM with the IP timed to 1.4mm plunger lift @ TDC. Accurately checking it now finds it at 2.8mm plunger lift (IP gear jumped two teeth plus a bit under 1/16" past the stock mark). Did anybody ever figure out a way to accurately convert that to degrees relative to TDC?

wannadiesel

Great Scott! You have to be somewhere around 16 degrees base timing, which would put you up around 25 degrees total. Is it gettin' cranky when you try to start it yet?

I recall reading somewhere (probably an old Pastor Bob post) that 1.4 mm worked out to 16 degrees of total timing. The ramp on the cam ring is not linear, so 2.8 mm does not mean double the timing.

BC847

It starts OK. If I had to be critical, I'd say it might take all of one full engine rotation to hit and go.

I kinda figured that was a lot of advance. I think a lowered compression ratio is letting me get away with a bit more.

I wish I knew what my compression ratio was. I'm running a 0.010" over head-gasket with a head that's had the valves unshrouded some. I'm pretty sure that drops the CR a little, just don't know how much. I should have CC'ed at least one of the head pockets.





That may explain why an easy calculation isn't available.

soggy

Undergoing some major changes again? Looks like you will beat me to the 12s,. JK, good luck.

big stinky

Neato! Any pics of under the valves? Whos head is that? Or did you have it "done"?

sdubfid

its a pdr head as far as i know

BC847

I'm replacing the HX35 hybrid with an S300 (62/14) and some other stuff.

It's a PDR head that fortunately for me had it's casting cores in the right places.

soggy

What does "some other stuff consist of"???