I have a jd 27d powered by a Isuzu 3ld1. The head has a "Plug" near the lift point bracket that I cannot locate on any schematic anywhere. It is NOT one of the threaded allen bolt type plugs (show on many schematics). It plugs an area of the head where oil flows. The hole is not threaded. It blew out and dumped all the oil on the ground before I knew what happened. I am in the final stages of a rebuild. So far John Deere and Isuzu have been no help. Has anyone had any experience with this? What is it? I will try to post pictures if anyone has any idea what the heck it is. My rebuilder want s to weld over the hole. John Deere has suggested tapping the hole and putting bolt in it. Any help will be appreciated. It's been a pretty good little machine and I'd like to fix it.
I read a thread earlier about someone experiencing blow by with one of these motors because of a plugged crankcase vent. I also experienced serious blow by. I was changing the oil. The maintenance schedule and capacities posted on the door of the machine gives 6.7 quarts of oil as the crankcase capacity. Why, I'll never know. I put about five quarts in it and decided to check it. It was well over full. I drained it to the proper level without ever starting it but probably plugged a vent or check valve. When I started it, all hell broke loose. I didn't know what happened. By the time I shut it down the damage was done. When we tore the engine down, we couldn't find anything to explain the blow by. I had expected a sucked valve, hole in piston scenario. After reading a post on this site, I understand what probably happened. The question still remains, what is the unthreaded plug in the head and where do I get another one or does it even need to be replaced? Can it just be blocked off?
Welcome to HEF bob ! Yes, please post pictures of the plug in question. Also post the serial number.
Engine serial number 227004 Machine serial number ff027x220178*
That machine serial does not come up. Post a picture of the machine serial plate along with the picture of the plug in question.
#8???
I cut off the last number of the machine. I assure you it is 8. The is an asterisk on both ends of the number. The plug hole is located at the base of the head, under the lifting bracket and allen bolt. The close up shows it unthreaded and chamfered. I a have looked at the schematic you posted in several places. It doesn't show it. It could possibly be #25 but the location is different.
Probably is #25. Since the head is off, why not size and tap it for a pipe plug?
I agree with HM. Just tap it and put a threaded plug in it.
Yup, That's what I think we will do.