toomanyprojects
New member
- Joined
- Feb 9, 2021
- Messages
- 6
- Tractor
- 1963 MF 65
I posted on other tractor forums but got no response so hopefully I can here.
I picked up a 1963 MF 65 with the Perkins AD4 203 diesel engine. All in all it works good. But the issue I'm trying to solve is it has a slow flow of oil running out of a hole in the timing cover. I checked and there isn't supposed to be a bolt there.
My theory at this time, is the oil pressure relief valve is stuck closed.
It only flows oil when it's running and it doesn't start flowing until the engine has ran for about 2 minutes.
It's not a ton of flow but you can watch it drip out.
I have seen other posts online about it from years ago but no one ever came back to post with the cause and solution. So it seems to be some what common.
I haven't replaced the oil gauge yet, it has the original one. I plan to put a new one on that reads the pressure in numbers instead of low, good and high. That way I can see if there is a blockage. I believe the correct PSI is 30-65. 65 when cold. 30 when warm.
When I run it now (for 5-10 minutes) the oil pressure gauge goes straight into the good area on the gauge and it never goes down from where it starts. If I rev up it will go up a tiny bit but not much. Haven't ran it other than to drive it and see if anything changes by driving it.
I'm running 15w40 oil, so nothing odd there. Clean oil. I've flushed the oil twice now. Once when I first got it. Second time was to make sure it had exactly what the service spec is for capacity. I thought maybe the dipstick was incorrect as it could've been swapped but it was correct. New oil filter as well.
I took the filter off and ran the engine for a second, thinking there might be a blockage to that... there isn't. Plenty of oil flow to it.
I'm not terribly familiar with oil pressure relief valves. I understand their purpose but I don't know where the oil flows to when it opens, so I'm unsure how to diagnose without taking the oil pan off.
My guess is the oil pump runs oil to all the passages but the relief valve releases the oil from the filter when the engine is running. I'm guessing this because I've watched a teardown of a perkins 236 and the relief valve was on the same side as the oil filter. So basically when the relief valve is closed, there is no oil filtration. It just sends oil to the filter but not out. When the relief valve opens, it is then filtering the oil and in turn also releasing oil pressure. Am I right or am I wrong?
Also any tips to diagnose a stuck closed oil pressure relief valve?
Trying to diagnose this before I take the time to take the frontend off.
I picked up a 1963 MF 65 with the Perkins AD4 203 diesel engine. All in all it works good. But the issue I'm trying to solve is it has a slow flow of oil running out of a hole in the timing cover. I checked and there isn't supposed to be a bolt there.
My theory at this time, is the oil pressure relief valve is stuck closed.
It only flows oil when it's running and it doesn't start flowing until the engine has ran for about 2 minutes.
It's not a ton of flow but you can watch it drip out.
I have seen other posts online about it from years ago but no one ever came back to post with the cause and solution. So it seems to be some what common.
I haven't replaced the oil gauge yet, it has the original one. I plan to put a new one on that reads the pressure in numbers instead of low, good and high. That way I can see if there is a blockage. I believe the correct PSI is 30-65. 65 when cold. 30 when warm.
When I run it now (for 5-10 minutes) the oil pressure gauge goes straight into the good area on the gauge and it never goes down from where it starts. If I rev up it will go up a tiny bit but not much. Haven't ran it other than to drive it and see if anything changes by driving it.
I'm running 15w40 oil, so nothing odd there. Clean oil. I've flushed the oil twice now. Once when I first got it. Second time was to make sure it had exactly what the service spec is for capacity. I thought maybe the dipstick was incorrect as it could've been swapped but it was correct. New oil filter as well.
I took the filter off and ran the engine for a second, thinking there might be a blockage to that... there isn't. Plenty of oil flow to it.
I'm not terribly familiar with oil pressure relief valves. I understand their purpose but I don't know where the oil flows to when it opens, so I'm unsure how to diagnose without taking the oil pan off.
My guess is the oil pump runs oil to all the passages but the relief valve releases the oil from the filter when the engine is running. I'm guessing this because I've watched a teardown of a perkins 236 and the relief valve was on the same side as the oil filter. So basically when the relief valve is closed, there is no oil filtration. It just sends oil to the filter but not out. When the relief valve opens, it is then filtering the oil and in turn also releasing oil pressure. Am I right or am I wrong?
Also any tips to diagnose a stuck closed oil pressure relief valve?
Trying to diagnose this before I take the time to take the frontend off.
