D 15 Series II engine question
Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Farm Equipment
Forum Description: everything about Allis-Chalmers farm equipment
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=209302
Printed Date: 31 Jan 2026 at 1:10am
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: D 15 Series II engine question
Posted By: jpi72
Subject: D 15 Series II engine question
Date Posted: 10 Dec 2025 at 2:15pm
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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. Joel
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Replies:
Posted By: DSeries4
Date Posted: 10 Dec 2025 at 2:39pm
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It's a stout engine with no known issues. Could be a stuck valve? You won't know until you open it up. ------------- '49 G, '54 WD45, '55 CA, '56 WD45D, '57 WD45, '58 D14, '59 D14, '60 D14, '63 D15D, '66 D15II, '66 D21II, '67 D17IV, '67 D17IVD, '67 190XTD, '73 620, '76 185, '77 175, '84 8030, '85 6080 |
Posted By: DiyDave
Date Posted: 10 Dec 2025 at 3:26pm
#'s 2 and 3 are closest to the upright muffler. Could be as easy as rust hanging a valve open... ------------- Source: Babylon Bee. Sponsored by BRAWNDO, its got what you need! |
Posted By: steve(ill)
Date Posted: 10 Dec 2025 at 3:50pm
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take the valve cover off and look at the valves now... then you can narrow down any work on the head ... ------------- Like them all, but love the "B"s. |
Posted By: WF owner
Date Posted: 10 Dec 2025 at 5:31pm
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. |
Posted By: steve(ill)
Date Posted: 10 Dec 2025 at 5:41pm
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since #2 and #3 are 180 degrees apart, you would think if the head gasket was blown, youi would have zero compression on both cylinders ?? ... when one cylinder is on COMPRESSION, the exhaust valve is open on the other cylinder.. ------------- Like them all, but love the "B"s. |
Posted By: WF owner
Date Posted: 10 Dec 2025 at 5:57pm
| It was a while back, but I believe I had about 60 psi on 2 & 3 and close to 150 on 1 & 4. |
Posted By: WF owner
Date Posted: 10 Dec 2025 at 6:07pm
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Here is a link to my post about it. https://www.allischalmers.com/forum/d15-series-2-skipping_topic207345_post1775129.html?KW=D%2D15#1775129" rel="nofollow - D-15 Series 2 skipping - AllisChalmers Forum
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Posted By: edognight
Date Posted: 29 Jan 2026 at 8:04am
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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. |
Posted By: steve(ill)
Date Posted: 29 Jan 2026 at 8:17am
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joel has not been back to this site since this post 45 days ago... Sure would be nice to know what he found ? ------------- Like them all, but love the "B"s. |
Posted By: PaulB
Date Posted: 29 Jan 2026 at 8:18am
It's been my experience that things from down south have been beat to death worse than a rented mule.  ------------- If it was fun to pull in LOW gear, I could have a John Deere. Real pullers don't have speed limits. If you can't make it GO... make it SHINY |
edognight wrote:Posted By: SteveM C/IL
Date Posted: 29 Jan 2026 at 10:19am
| I had a great mentor who said the same |
Posted By: jpi72
Date Posted: 29 Jan 2026 at 8:27pm
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Yes, I am overdue for an update. We did get the valve spring reattached to the valve without removing the head. We had zero compression in that cylinder. We took the head off of the engine. The valve was bent enough that it would not close properly. That accounted for the zero compression. The piston had a blemish where the valve had hit it. The cylinder wall had one small line in it that went up and down. My son and I decided the damage was not worth a complete tear down. So new gaskets and put it back together. it runs fine. We are guessing the engine is around 60 years old and now has some internal scars. Feel blessed that the damage was not worse. Thank again to all of the input. It is a real help when you are guessing what is wrong with the engine. Joel
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Posted By: Uncle Al
Date Posted: 29 Jan 2026 at 10:16pm
| Reminds me of when we were racing an IMCA modified on a 3/8 mile dirt oval a few years ago. Leading the a main and the engine developed a bit of a flutter. Didn’t seem to be down on horsepower as we kept the lead. With two laps to go there was a caution flag and as soon as he got off the throttle one cylinder went dead. As luck would have it the caution lasted long enough that they called the race and paid us for the win. When we pulled the valve cover on the small block Chevy there was a broken valve spring and the creepers came out and dropped the valve. Bent the valve a bit and pushed it back up into the guide with a barely visible nick on the piston. We drove the valve out cleaned up the minor damage to the guide and put a new valve and spring and we ready to go again. Sometimes it is better to be lucky than good! |
Posted By: Ed (Ont)
Date Posted: 30 Jan 2026 at 7:20pm
| Now that's the way to win a race! Lol!!! |