Exhaust manifold oil leak: Aus HJ60 2H+Turbo (1 Viewer)

[pacalis]

Hi everyone, so I'm troubleshooting a few issues with my 85HJ60 (Aus spec) and would love your help/advice.

My 2H engine with an aftermarket turbo has done 424,000km and has the following symtoms:
- Blows black smoke when running for an hour
- Blowby (not sure if excessive)
- Catch can fills up fairly regularly

Most alarmingly, the exhaust manifold shows oil leaks from exhaust port 1 and 6.

One shop has told me that this means engine rebuild time (between 5k 7k). But I'd like to know if it could be anything else?

I've searched this forum and haven't really found anything specific to this issue. So really looking forward to learning from guys.

 

[Freewheel]

First off, do a compression test or have one done for you. It's $100 bucks well spent for figuring out what's happening with your truck.
424,000 is a LOT of mileage for a turbocharged 2H.

Melbourne is generally so warm that you might not have the warning signs of low compression that us cold country users get. (hard starting and clouds of white smoke until the truck warms up)

I'm not sure what oil leaks from the exhaust means either, but it seems like it could mean your oil rings are shot in those cylinders.
The biggest issue with a 2H is the piston rings eating into the unreinforced stock piston ring lands. This creates play in in the ring lands that shows up as compression issues and eventually, broken rings. High levels of blowby are another strong symptom of ring land issues. And as your shop suggested, bad ring lands mean new pistons and rings, which means you're in for a full top end rebuild...and since you're in there on a high mileage engine, you should probably pull the whole thing apart.

I'm not sure about the black smoke issue- Usually that colour smoke is from overfuelling- might be a separate issue...

 

[pacalis]

Thanks for the detailed info!

Comp test came back even across all cylinders.. so I'm confused there. Results below cold/hot:

1: 420/440
2: 453/420
3: 340/420
4: 425/440
5: 420/440
6: 450/430

Will it run for a bit longer or should I stop driving it straight away? We were planning a few days camping over christmas and new year. And then get stuck into the rebuild.
I think the turbo was added around 9-10 years ago based off the dates on the air filter etc.

As for the black smoke, I think that's fuel/boost issue. I'm working on that and should hopefully sort it soon.

 

[Freewheel]

Hmm, those numbers are pretty good! When mine went, I was at 440,420,420,400,240,380 warm. The 240 cylinder was really causing some starting issues, though it ran perfectly when warmed up. Looks like you should be OK on your piston rings.

How much oil is the engine using? Maybe the valve seals/guides are worn? That could let oil into the cylinders, while still having decent compression...

 

[Freewheel]

You're not getting much conversation in this forum, maybe repost in the 24 volt/diesel forum. I bet you'd get some more opinions and ideas.

 

[pacalis]

I haven't measured exactly, but I'll for a short run tonight and then see what the catch can has.

Move to the 24 volt/diesel forum? I didn't think that a 2H engine question would work there. But I'll post up.

Thanks for the info tho!