This Perkins engine will run fine, till out of nowhere it'll start misfiring & sputtering. It looses nearly all horsepower & backfires through the exhaust. White & Black smoke billows out. Here is a video clip on my facebook to demonstrate it happening. https://www.facebook.com/photo.php?v=990865690939212 When that happens it'll go back to running normal again by; Taking the load off, run it at idle, or let it sit for over 30 min. To narrow it down; it's not a dirty air filter, not water in fuel, it's not turbocharged, engine does not overheat, coolant is in good shape but it guzzles motor oil. I'd really like to fix this while we have this engine out (repairing the torque converter) and on the verge of doing a complete overhaul, but if theres a simpler fix, I'm all ears. Any advice is much appreciated.
My guess is the fuel supply. The pump would be my first check.
Hard to tell from a distance . I would check valve clearance and valve springs. sounds like a valve not seating or sticking. I would also look for air in the fuel supply but it seems to come and go too quickly for that.
I'm with mobiltech, inspect the valve train and adjust, probably sucking oil past the valve guides, and burning past a sticking intake valve.
I am surprised that the 850 has a Perkins diesel, in all my years I have never seen anything but a genuine Case engine in one, unless it is a transplant and I don't know why one would ever go to a Perkins as the Case diesel was one of the best engines ever built. I would like to see pictures of the engine close up if you can post them, Mel
I would like to see pictures of the engine close up if you can post them, Mel[/QUOTE] I was able to make it out today and get some decent photos. I have no idea why any1 would down-grade. My only guess is maybe the original engine block cracked & swapped it. Anyways, here goes the motor... View attachment 127234 View attachment 127235 View attachment 127236 This is embossed on the head. View attachment 127237 This shows where the CASE motor should be mounted vs where this motor was mounted on the chassis. View attachment 127238 I am at a loss as to what is causing this machine to randomly misfire & what to do about it. I took out the injectors & they had a medium-to-heavy carbon buildup on the nozzle & needle. We shot them w/ carb-n-choke cleaner. Some of the orifices (4 per nozzle) were fully clogged, but all started as a stream & kept cleaning till a spray pattern emerged. The service manual mentions that as a possible cause for misfiring too. So do I overhaul it? Is there a way to test for sticking valves, bent valves and/or guides, sticking piston rings, etc ...w/o having to dismantle the engine? I do want to express my gratitude towards all the folks for taking the time & effort to be helpful for others. This is an awesome site.
I was able to make it out today and get some decent photos. I have no idea why any1 would down-grade. My only guess is maybe the original engine block cracked & swapped it. Anyways, here goes the motor... This is embossed on the head. This shows where the CASE motor should be mounted vs where this motor was mounted on the chassis. I am at a loss as to what is causing this machine to randomly misfire & what to do about it. I took out the injectors & they had a medium-to-heavy carbon buildup on the nozzle & needle. We shot them w/ carb-n-choke cleaner. Some of the orifices (4 per nozzle) were fully clogged, but all started as a stream & kept cleaning till a spray pattern emerged. The service manual mentions that as a possible cause for misfiring too. So do I overhaul it? Is there a way to test for sticking valves, bent valves and/or guides, sticking piston rings, etc ...w/o having to dismantle the engine? I do want to express my gratitude towards all the folks for taking the time & effort to be helpful for others. This is an awesome site.
A compression test while it was still in may have given you a better idea. The fact that you stated it "guzzled" oil is a good indicator that the rings and or valve's could be shot. Also, when it warmed up, is when it started these symptoms, indicating something is expanding inside. Since it's already out and if you have the money, I'd go for the rebuild. You could just have them pull the head off and take a look inside, they'll let you know what you should do from there, maybe just a head rebuild, who knows. While your at it, get the injection pump done also and the injectors cleaned.
While not a big fan of Perkins engines you would almost look at that transplant as an upgrade as the Case is a 301 and I believe that 6 cyl is a 354 as used in some larger Massey Ferguson Ag tractors. If the crawlers overall condition warrants it I believe I would do a major and reinstall it. The Perkins is a dry sleeve engine, a bit different to resleeve. Have the pump and injectors gone over, the injectors can be retipped relatively inexpensively. I think I would try to find a pair of rubber engine mounts to use as it looks like they just bolted it down solid. Mel
the Perkins overhaul manual calls for only 12 torque lbs for the fuel injectors. that doesn't seem to be nearly enough. can verify that fuel injectors need only 12foot lbs, or did the manual make a misprint? keep in mind that the engines compression is about 400psi. I'm nearly done with this engine & torque converter restoration, so I'm eager to hear it all running again. I'll glad post the after pix shortly. some of you folks wont even recognize it as being the same engine