onefarmer
Well-known Member
- Location
- 6735 S Lowell Rd, St Johns, Mi 48879
I know diagnosing a knock without being there is near impossible but.....
My 4430 has a knock starting when it gets to about 1200rpm and gets worse from there. It comes from the center of the engine, in the upper part like in the cylinder area. Between cyls 3 and 4. I'm not sure but from the sound it could be piston slap, a bad piston pin bushing. It might be but I don't think it's the piston hitting the head.
The engine has good oil pressure. I set the engine speed so it just barely knock and loosened the injector lines and there was no change in the level of the knock.
No it's not the pump coupler. That's the first thing I tried.
Anything else to try or look for before tearing into it?
Anything to look for while tearing into it?
Any helpful advise is appreciated.
My 4430 has a knock starting when it gets to about 1200rpm and gets worse from there. It comes from the center of the engine, in the upper part like in the cylinder area. Between cyls 3 and 4. I'm not sure but from the sound it could be piston slap, a bad piston pin bushing. It might be but I don't think it's the piston hitting the head.
The engine has good oil pressure. I set the engine speed so it just barely knock and loosened the injector lines and there was no change in the level of the knock.
No it's not the pump coupler. That's the first thing I tried.
Anything else to try or look for before tearing into it?
Anything to look for while tearing into it?
Any helpful advise is appreciated.