tool

I have an older 970 case that is making oil like crazy, obviously dumping fuel into the oil.

Starts and runs fine, slight miss, no wild smoke but oil level creeps up, dumped the oil today and it is thin, obviously fuel not water.

Any ideas where to start looking?

DiezelSmoke

Probably the injection pump, they had a couple different kinds installed on them over the years. What name is on the injection pump?

tool

It's a Bosch pump.

Alwaysworking

or the lift pump

mcoleman

I know on the Cav pumped Perkins engines like in my Super 90 Massey, the seal on the shaft will go bad and allow fuel to leak into the crankcase. If the mechnical lift pump goes bad it can also leak into the crankcase. The only other thing would be an injector and with the miss that's a possiblity.

tool

Yeah I agree with you mcoleman.

The trick is figuring which one of those issues that the problem is.

I guess I start with injectors and work backwards.

DiezelSmoke

At this point the lift pump is far cheaper and probably the cause.

tool

I hope your right,

Any idea what I would look for or how I would test the lift pump to see if that is infact the cause?

Due to the miss, I'm guessing it's not the lift pump. But optimism makes me hope ur right.

DiezelSmoke

I would just replace the pump, it's tough to try and tell you how to test the pump and then it's a very good possibility it won't show up anyhow. The lift pump will be about $50.00. The lift pump could be sucking air and causing an engine miss. You can put a clear plastic line on the return line and see if you have air in the fuel system. Do this before doing any engine work. Another thing to do is start the engine cold and feel the exhaust port on every cylinder and see if they all warm up at the same time or are the same temp as one another, this will give you an idea which cylinder or injector is bad.

tool

Yeah, that's along my thinking too.

I've got one of those laser thermometer things, I was going to run it and check for a cold cylinder.

Then pull that injector, check for compression, bench test the injector, and go from there I guess.

DiezelSmoke

I wasn't very clear in my last post, quoting you above. A bad injector will not do this. I'm not saying you don't have a bad injector or weak cylinder, but unless it is hammering or an ablsolute dead miss, even then, it won't be an injector causing it to make oil like crazy.
It will be a lift pump or a seal in the Inj pump, 99.9%.

tool

DiezelSmoke, I think you are probably right.

Do you think removing the lift pump and inspecting it would tell me anything?