Hi, thanks for some past help from fellow forum members. Now an new issue.
Background:
I have a mid-70's Ford 750 backhoe, got her for a song and after a lot of work she's running. Nothing like a "cheap" machine.
Originally: I was told turbo (#1) apparently blew, lots of black smoke, sat in field for a year or two, engine filled with water, frozen, etc. That's when I got her, got the engine working in the field, put on a new turbo (#2), and drove her home. However, I then discovered that the real problem, likely leading to the original demise, was a pinhole in a cylinder causing coolant to leak into the oil and turn it into a nice grey milkshake (and hence zorching the turbo bearings). The #2 turbo bearings were done too, but I rebuilt it. The shaft was still a little loose, but workable for the time being as I ultimately discovered the pinhole issue.
I had the blocked sleeved and no more oil leak. I probably should have done the crankshaft too but runs okay, a little knocking. Turbo #2 was getting a little too loose so I got yet another turbo (#3) and installed it. It ran fine okay for probably 20 hrs, though smokey. Turbo #2 had a higher than spec ratio and made less smoke, so I originally attributed the smokiness to the difference.
Now the current problem:
Turbo #3 suddenly started puking oil out of the turbine end into the exhaust. I immediately checked the oil and added all of about 5 quarts!! (wow... 11 quart capacity). I had checked the oil when I put turbo #3 in, so the excessive consumption occurred in that time frame. Also, oil was dripping down the side of the engine and was sprayed around a bit, some obviously coming from the turbo, but it also seemed like some was squirting out from the return line fitting. I cleaned up the mess, fixed a seal on the return line, checked the turbo shaft play (which was tight) and everything was fine until it suddenly happened again.
Not knowing much about this issue I did a little research and it seem like the problem is some combination of:
- crankcase over-pressure (though crankcase/valve cover vent is clear)
- clogged return line (doesn't seem to be the case)
- some clog in the turbo cartridge (haven't taken it apart yet)
What I did do was disconnect the bottom end of the return line, start the engine, and observe how much oil was flowing. It was basically a continuous but small drizzle, the kind you get when you're eeking the last bit of oil out of a quart jug. Maybe 1/2 cup per minute.
Question: is this right?? I can't find any spec's but it sure doesn't seem so.
I'm guessing some of the orifices in the cartridge at this point are in fact clogged, possibly from the turbo having overheated and burning some oil in it, when it should have gotten a cool down period. Plan A is to pull the turbo and overhaul it. I'm also waiting for parts for #2, which always worked fine aside from the bearing issue.
However, all this doesn't explain the possible squirting out from the return line fitting. That area was pretty wet and clearly some oil squirted out of somewhere. It just didn't look like it all came from the turbine.
Ideas on any of this? Any suggestions appreciated.
Side note: when I started the engine with the return line disconnected from the sump, some oil did splash out of the fitting that leads to the sump, which wasn't a surprise. Would it be possible though that under certain circumstances enough oil could splash up to basically vapor lock the return line? It's all very puzzling.
Thanks in advance.
Background:
I have a mid-70's Ford 750 backhoe, got her for a song and after a lot of work she's running. Nothing like a "cheap" machine.
Originally: I was told turbo (#1) apparently blew, lots of black smoke, sat in field for a year or two, engine filled with water, frozen, etc. That's when I got her, got the engine working in the field, put on a new turbo (#2), and drove her home. However, I then discovered that the real problem, likely leading to the original demise, was a pinhole in a cylinder causing coolant to leak into the oil and turn it into a nice grey milkshake (and hence zorching the turbo bearings). The #2 turbo bearings were done too, but I rebuilt it. The shaft was still a little loose, but workable for the time being as I ultimately discovered the pinhole issue.
I had the blocked sleeved and no more oil leak. I probably should have done the crankshaft too but runs okay, a little knocking. Turbo #2 was getting a little too loose so I got yet another turbo (#3) and installed it. It ran fine okay for probably 20 hrs, though smokey. Turbo #2 had a higher than spec ratio and made less smoke, so I originally attributed the smokiness to the difference.
Now the current problem:
Turbo #3 suddenly started puking oil out of the turbine end into the exhaust. I immediately checked the oil and added all of about 5 quarts!! (wow... 11 quart capacity). I had checked the oil when I put turbo #3 in, so the excessive consumption occurred in that time frame. Also, oil was dripping down the side of the engine and was sprayed around a bit, some obviously coming from the turbo, but it also seemed like some was squirting out from the return line fitting. I cleaned up the mess, fixed a seal on the return line, checked the turbo shaft play (which was tight) and everything was fine until it suddenly happened again.
Not knowing much about this issue I did a little research and it seem like the problem is some combination of:
- crankcase over-pressure (though crankcase/valve cover vent is clear)
- clogged return line (doesn't seem to be the case)
- some clog in the turbo cartridge (haven't taken it apart yet)
What I did do was disconnect the bottom end of the return line, start the engine, and observe how much oil was flowing. It was basically a continuous but small drizzle, the kind you get when you're eeking the last bit of oil out of a quart jug. Maybe 1/2 cup per minute.
Question: is this right?? I can't find any spec's but it sure doesn't seem so.
I'm guessing some of the orifices in the cartridge at this point are in fact clogged, possibly from the turbo having overheated and burning some oil in it, when it should have gotten a cool down period. Plan A is to pull the turbo and overhaul it. I'm also waiting for parts for #2, which always worked fine aside from the bearing issue.
However, all this doesn't explain the possible squirting out from the return line fitting. That area was pretty wet and clearly some oil squirted out of somewhere. It just didn't look like it all came from the turbine.
Ideas on any of this? Any suggestions appreciated.
Side note: when I started the engine with the return line disconnected from the sump, some oil did splash out of the fitting that leads to the sump, which wasn't a surprise. Would it be possible though that under certain circumstances enough oil could splash up to basically vapor lock the return line? It's all very puzzling.
Thanks in advance.