Bullseye T&L
ArboristSite Member
I've had this machine for 2 years. Picked it up with 930 hours, now has 1,180 hours. There is a noise I'm hearing that I can't identify. It's been going on for the last 100 hours for sure, but thinking back, I think it's been there all along and my ears are now tuned to it. Two other people I've had listen to it can't really distinguish the noise and think I'm crazy. It's coming from the top of the engine (40hp Kohler) and sounds similar to a machine gun when it happens. I have tried to capture the sound on on my phone, but I can't get a good recording. It only happens 1) after the temp hits 145*F, and 2) only under some sort of load - usually like a hard turn at low engine rpm, or [sometimes] when the hydraulics are working hard. I have listened all over the machine, and I pretty sure it's coming from the upper part of engine and not the hydraulic pump. The hotter the engine temp, the more often I hear it.
I originally thought it might be carbon buildup on pistons, so I have tried running high concentration of Seafoam in fuel, but it hasn't really changed anything. I also quit using cetane booster thinking that it might be preignition - and I believe that actually helped some. I then started using Marvel Mystery oil to potentially clear any carbon, but I haven't done that for very long. Now, I'm beginning to wonder if it's not the injectors.
Any ideas?
I originally thought it might be carbon buildup on pistons, so I have tried running high concentration of Seafoam in fuel, but it hasn't really changed anything. I also quit using cetane booster thinking that it might be preignition - and I believe that actually helped some. I then started using Marvel Mystery oil to potentially clear any carbon, but I haven't done that for very long. Now, I'm beginning to wonder if it's not the injectors.
Any ideas?
