Oil Sprays from Engine Breather on Jinma 284

[TruChaos]

My Jinma 284, which now has over 100 hours on it, has a couple issues. When I feed the chipper and load down the engine, I get puffs of blue smoke. But this only seems to happen 50 percent of the time. Sometimes it's worse than other times as well. I can turn the engine off , go get a drink of water, then restart and poof, no smoke.

Also, a few times now, oil has sprayed from the engine breather. At first I thought I had a leaky hydraulic line, but it was the breather. Again, this only occurs once every 4 or 5 times I use the chipper.

It has done these things since I have owned the tractor. Regardless of oil manufacturer, or viscosity. Oil is not over filled and is about half way between the upper and lower marks. Oil seems to stay amazingly clean although I do change it every 20 hours, so I guess it doesn't get a chance to get dirty. My car engine dirties its oil in far fewer hours.

I also have an intermitent rough running problem and have swapped injectors with little effect. I've bled the lines many times, changed fuel filters, replaced fuel lines, cleaned the banjo filter, checked the tank filter, checked the injection timing, etc, etc. Every once in a while, when the engine is hot, the engine will develop a knock for just a few seconds then it goes away. Again, this happens with Rotella, or Castrol. Oil pressure is good at 40 to 60 psi hot at 2400 RPM. 30+ PSI idle. Compression is good and consistent in each cylinder at 550 PSI. Engine always starts easily without glow plugs.

I've long suspected the injection pump and have tried various oils (Honda pump oil, Mobil 1, Rotella, etc.) but the problems remain. I've taken the top off the injector pump and inspected the pistons, they all look good with no apparent wear, marks or galling.

The tractor runs fairly well but I'm sure I'm missing something.

Any suggestions? Or recommendations?

Thanks in advance.

 

[greg_g]

Oil through the breather from an engine with a proper oil level can be caused by overpressure in the crankcase. You say your compression checks good, which makes tracking down the source a bit more difficult. Did you ever retorque the headbolts during that 100 hours? Adjust your valves?

Also - a one time occasion of overpressure could have left standing oil in the breather. Have you washed it out with diesel yet? I wash and dry mine at least once or twice a year.

I'm not sure about your reference to the injection pump. Is there some reason that you think fuel delivery is related to oil in the breather?

//greg//

 

[RonMar]

Is it smoke or steam comming out of the breather? Can you get some on your hand or glove and see what it smells like? A leaking headgasket could put a little coolant into the oil which cooks off when the engine gets hot. An excessive buildup of condensation in the case(Shutdown during really damp conditions)could also do the same thing. Excessive water at the bottom of the oilpan could boil and errupt into the oil causing oil to make it to the breater port and be expelled. I think with that much water you would see other symptoms in the oil though such as a light brown milky sludge from water emulsification. There is a hose that runs from the oil fill cap to the intake manifold. The restriction of the airfilter should keep this hose and the crankcase under a very slight vacume when the engine is running. That breather should only ever admit air into the case. The fact that something is comming out indicates a source of supply greater than that vacume line to the intake can draw back thru the intake manifold. A leaking headgasket could also add pressure to the case via an oil return port or valve pushrod port, but I think you would be seeing some fluid transfer in there also. And good compression is good compression.

Have you looked at the injector spray patterns? A dribbling injector could add excessive unvaporized fuel to the piston and cylinder which would contribute to more fuel making it past the rings, but more carbon and unburnt fuel residue in the exhaust also. Excessive fuel in the oil could also flash into visible vapor and boil under the right conditions of an extended hot run. The vapors can also ignite in the case under the right conditions. A faulty injector spray pattern or firing pressure could also explain the missfire.

 

[TruChaos]

Oil through the breather from an engine with a proper oil level can be caused by overpressure in the crankcase. You say your compression checks good, which makes tracking down the source a bit more difficult. Did you ever retorque the headbolts during that 100 hours? Adjust your valves?

Also - a one time occasion of overpressure could have left standing oil in the breather. Have you washed it out with diesel yet? I wash and dry mine at least once or twice a year.

I'm not sure about your reference to the injection pump. Is there some reason that you think fuel delivery is related to oil in the breather?

//greg//

Thanks for the reply.


Yes, I retorqued the heads, checked the valves and checked the injection timing. Everything was as it should be.

I haven't cleaned the breather but the volume of oil is beyond a spray its big fat drops. It flings oil and the fan blows it back all over the right foot board and fender. I'll check to see if the breather is full, if that's possible. The first time I noticed the oil was when I was running the chipper on an slope with the tractor tilted to the right. But since then, it has always happened on flat level ground.

I've wondered if the Chinese dipstick is made to the wrong length. I noticed the measuring stick part is hand brazed into the ring handle. Do you know the proper length of the measuring stick for a 2004 284?

I mentioned the injector pump because I suspected it could be the cause of the intermitent knocking sound if fuel pressure is lost briefly to an injector and it could be the cause of the occasional rough running of the engine and the blue smoke if a cylinder is fuel starved. As far as a connection to oil in the breather, no I can't think of a connection.

 

[TruChaos]

Is it smoke or steam comming out of the breather? Can you get some on your hand or glove and see what it smells like? A leaking headgasket could put a little coolant into the oil which cooks off when the engine gets hot. An excessive buildup of condensation in the case(Shutdown during really damp conditions)could also do the same thing. Excessive water at the bottom of the oilpan could boil and errupt into the oil causing oil to make it to the breater port and be expelled. I think with that much water you would see other symptoms in the oil though such as a light brown milky sludge from water emulsification. There is a hose that runs from the oil fill cap to the intake manifold. The restriction of the airfilter should keep this hose and the crankcase under a very slight vacume when the engine is running. That breather should only ever admit air into the case. The fact that something is comming out indicates a source of supply greater than that vacume line to the intake can draw back thru the intake manifold. A leaking headgasket could also add pressure to the case via an oil return port or valve pushrod port, but I think you would be seeing some fluid transfer in there also. And good compression is good compression.

Have you looked at the injector spray patterns? A dribbling injector could add excessive unvaporized fuel to the piston and cylinder which would contribute to more fuel making it past the rings, but more carbon and unburnt fuel residue in the exhaust also. Excessive fuel in the oil could also flash into visible vapor and boil under the right conditions of an extended hot run. The vapors can also ignite in the case under the right conditions. A faulty injector spray pattern or firing pressure could also explain the missfire.

Thanks for the reply.

No, there isn't any water vapor anywhere, including under the oil filler cap. Also, there is no oil in the coolant. Nor have I ever smelled coolant vapor (recovery bottle).

Yes, I have checked the injector spray pattern and I have even disassembled, cleaned and re-calibrated the opening pressure of the original injectors, using a test fixture. I am currently using the EPA approved injectors. Having seen both on the test fixture, the EPA injectors make a very fine mist versus the pop and spray cone of the original injectors. There is a huge difference in spray pattern appearance but no real detectable difference in engine running.

 

[Egon]

Check the compression and pull the head.

 

[young2]

my 385 eng. dose the smoke but no spray. I have no fluid loss or anything.
I notice this more when the left side is down hill. Once I over filled it with oil an I really got a lot of smoke.I have no loss of power no rough running or anything.

 

[bjr]

For the rough running, try some of the Stanadyne fuel treatment. I've a old ford diesel tractor and I was really surpirsed at the difference in the runnining with the fuel treatment. I'm not a saleman for the stuff and don't normally go for all the miricle cures, but I was gettting ready to shell out serious dollars to get fuel system overhauled before I tried the fuel treatment. For the oil blowing out the breather keep trying the different oil levels in the crancase test. bjr

 

[doxford jim]

Thanks for the reply.

No, there isn't any water vapor anywhere, including under the oil filler cap. Also, there is no oil in the coolant. Nor have I ever smelled coolant vapor (recovery bottle).

Yes, I have checked the injector spray pattern and I have even disassembled, cleaned and re-calibrated the opening pressure of the original injectors, using a test fixture. I am currently using the EPA approved injectors. Having seen both on the test fixture, the EPA injectors make a very fine mist versus the pop and spray cone of the original injectors. There is a huge difference in spray pattern appearance but no real detectable difference in engine running.

Hi,

I am assuming that you have the inline Bosch type fuel pump, where the pump barrels are turned by the fuel rack. If that is the case and you are getting intermittent stumbling, have you checked the indiviual pump check valves. I have found that the check valves sometimes get crud under them and they then fail t shut properly, thus giving the symptoms if a faulty injector or pump. If the don't close properly then the pump doesn't get to work properly.

Just a thought and don't know if it applies in your case.

HTH

jim

 

[TruChaos]

Hi,

I am assuming that you have the inline Bosch type fuel pump, where the pump barrels are turned by the fuel rack. If that is the case and you are getting intermittent stumbling, have you checked the indiviual pump check valves. I have found that the check valves sometimes get crud under them and they then fail t shut properly, thus giving the symptoms if a faulty injector or pump. If the don't close properly then the pump doesn't get to work properly.

Jim,

Thanks for the reply, that was one of the first things I tried, after bleeding the lines etc.

Everything was spotless clean inside, not even a speck of dirt or crud.

I have tried fuel treatment but, I don't think it was the brand you mentioned. I didn't notice a difference. Except that the normal engine noise seemed a little louder.

Thanks again