D 15 Series II engine question

I own an AC forklift with a D15 Series II (160 cu. in) engine.  Cylinder 3 has zero compression currently.  It happened quite suddenly.  Does this engine have head problems?  We are planning on taking the head off after Christmas.

#'s 2 and 3 are closest to the upright muffler.  Could be as easy as rust hanging a valve open...

I have a D-15 II that I bought at the end of May 2025. It had a skip. When I did a compression check, #2 and #3 were down considerably on compression compared to #1 and #4. Here's what i found when I removed the head.

It was a while back, but I believe I had about 60 psi on 2 & 3 and close to 150 on 1 & 4.

I went thru this very recently, and on my 160, the valve seats, the parts recessed into the heads were gone on three cylinders! I did a compression test and one cyl was good, one was very low and two were zero. I sent everything to the machine shop, and very quickly the thing was up and running perfectly. there was zero damage to the piston tops.   

I'd have to agree, this is a tough engine. What must have happened was the owner just took it to the bitter end, until it did not run at all.

I am never again buying a machine with a tree growing thru it.   

edognight wrote: I went thru this very recently, and on my 160, the valve seats, the parts recessed into the heads were gone on three cylinders! I did a compression test and one cyl was good, one was very low and two were zero. I sent everything to the machine shop, and very quickly the thing was up and running perfectly. there was zero damage to the piston tops.    I'd have to agree, this is a tough engine. What must have happened was the owner just took it to the bitter end, until it did not run at all. I am never again buying a machine with a tree growing thru it.