1975 885 w/AD355. If a diesel engine exhibits evidence of wet stacking can the condition be addressed by increasing the operating temperature?
An incorrect thermostat (engine temp never raised above 130) was replaced about ten hours after an engine rebuild with a new thermostat with an indicated open temp of 172 and indeed the gauge never reaches 180. There was still residual nasty black evidence of wet stacking left in the manifold after the new thermostat was installed so I threaded the rain drain hole and installed a screw to keep the mess off the alternator until the manifold dried up. Removing the muffler occasionally showed the condition in the manifold much improved but I never bothered to remove the screw. I recently noticed some wet smudge where the manifold joins the muffler. I had removed the muffler to shorten it to clear the overhead door to the equipment shed. I was surprised to see the muffler largely sooted up inside. In fact, if the divider between the lower and upper muffler hadn't deteriorated I don't see how the exhaust could have gotten through. I knocked the rusted hole in the divider as large as I could and have used the tractor with what is basically a straight through exhaust. Even in hot weather after several hours of mowing there is that wet smudge coming from the muffler/manifold connection. The engine starts easily, even in thirty degree temps and runs great. At 80+ hours after the rebuild with the oil level never dropping below the full mark the oil was changed. Ran it all this year oil still on full. Oil is still clear. No smoke except right when the throttle is snapped open. I can only deduce I either don't run the engine hard enough or the coolant temp is too low to completely dry the inside of the exhaust manifold. Interesting that when the engine was in so poor a condition that it would not start even in ninety degree weather without starting fluid - the exhaust was bone dry.
This post was edited by ScottNC on 12/26/2022 at 07:29 am.
An incorrect thermostat (engine temp never raised above 130) was replaced about ten hours after an engine rebuild with a new thermostat with an indicated open temp of 172 and indeed the gauge never reaches 180. There was still residual nasty black evidence of wet stacking left in the manifold after the new thermostat was installed so I threaded the rain drain hole and installed a screw to keep the mess off the alternator until the manifold dried up. Removing the muffler occasionally showed the condition in the manifold much improved but I never bothered to remove the screw. I recently noticed some wet smudge where the manifold joins the muffler. I had removed the muffler to shorten it to clear the overhead door to the equipment shed. I was surprised to see the muffler largely sooted up inside. In fact, if the divider between the lower and upper muffler hadn't deteriorated I don't see how the exhaust could have gotten through. I knocked the rusted hole in the divider as large as I could and have used the tractor with what is basically a straight through exhaust. Even in hot weather after several hours of mowing there is that wet smudge coming from the muffler/manifold connection. The engine starts easily, even in thirty degree temps and runs great. At 80+ hours after the rebuild with the oil level never dropping below the full mark the oil was changed. Ran it all this year oil still on full. Oil is still clear. No smoke except right when the throttle is snapped open. I can only deduce I either don't run the engine hard enough or the coolant temp is too low to completely dry the inside of the exhaust manifold. Interesting that when the engine was in so poor a condition that it would not start even in ninety degree weather without starting fluid - the exhaust was bone dry.
This post was edited by ScottNC on 12/26/2022 at 07:29 am.
