C223 Rocker Arm Wear - Excessive?

The place to discuss problems and routine maintenance questions and tips. This is for topics that are specifically diesel-related.
Post Reply
User avatar
Siegfried
Regular Member
Posts: 27
Joined: Tue Mar 24, 2015 8:28 pm
Location: Virginia
Isuzu vehicle(s): 1985 P'UP Diesel

C223 Rocker Arm Wear - Excessive?

Post by Siegfried »

Hey all,

I've been trying to diagnose a ticking sound coming from my 1985 P'UP with the C223 motor. I checked valve lash and it seemed good, so I took the rocker arm assembly off and turned it over and saw the wear pattern in the pictures below. It looks like the valves ground indentations into the rocker arms. That is excessive, right? The tips of the valves have a concave surface that matches the rockers. Interestingly, the two valves on the very ends of the assembly seem to have much less wear, more like just polished spots on the bottoms.

Could this be the cause of engine ticking noises? How would I go about addressing this?

Underside of rockers:
Image

Tip of valve:
Image

A rocker on the end:
Image
1985 Isuzu P'UP Diesel Long Bed
ZUZUFLY
Regular Member
Posts: 27
Joined: Thu Aug 16, 2007 10:47 pm

Re: C223 Rocker Arm Wear - Excessive?

Post by ZUZUFLY »

That wear pattern seems to be kinda common in these engines. Rocker arms kinda soft I guess. My engine started to run like it had a dead cylinder, especially at idle. Did compression check. I found it to be the #1 or most fwd cylinder. Three cylinders had close to 400 lbs. The # 1 had about 200. not enough to ignite the fuel. Suspected burned valve. So I pulled off the head. Some rocker arms were like yours. I determined that this wear pattern had captured the valve stem tip into the worn hole and was causing a stem to guide rocking action that had worn the guide to where the the valve head to valve seat contacted off center. Reground valve seats and reground rocker arms. I replaced all guides and valves, gaskets etc. Fixed the problem. Bought the parts from RockAuto. That was probably 6 to 8 years ago. Hopefully you may have caught this in time. You may only need to regrind the rockers.
User avatar
puttputtinpup
Regular Member
Posts: 11495
Joined: Sat Oct 08, 2005 5:18 am
Location: Winston Salem, NC

Re: C223 Rocker Arm Wear - Excessive?

Post by puttputtinpup »

There was some discussion years ago about regrinding the rockers' contact surfaces and then parkerizing the new surface for added wear resistance. Jerry Lemon had made up a jig for himself to regrind the rockers.
Dieselsmoke69
Regular Member
Posts: 167
Joined: Sun Mar 21, 2021 12:23 pm
Location: MO
Isuzu vehicle(s): 1982 CHEVY LUV MIKADO C223 DIESEL 2wd,1981 Chevy Luv shortbed 2wd G180Z, 1981 Chevy Luv Mikado 4x4 G180Z redline weber 32/36

Re: C223 Rocker Arm Wear - Excessive?

Post by Dieselsmoke69 »

Without confirming current availability, i purchased a complete rocker set for a C-240 on E-bay about a year ago. Shafts and all assembled and complete. The C-240 Top End is the same as the C-223. You may check and see if they are still available under the C-240
User avatar
Siegfried
Regular Member
Posts: 27
Joined: Tue Mar 24, 2015 8:28 pm
Location: Virginia
Isuzu vehicle(s): 1985 P'UP Diesel

Re: C223 Rocker Arm Wear - Excessive?

Post by Siegfried »

Thanks for the feedback everyone. After reading your responses and talking to another gear head friend, I think what I should do is take the head off and give it to a shop to see if they can regrind these, and probably get new valves and valve guides and springs. Need to get it ready for another 200k miles!

There is a reputable shop local to me that can do the work but I wanted to ask is there a shop that has good experience with these engines that someone can recommend?
1985 Isuzu P'UP Diesel Long Bed
User avatar
Halden
Regular Member
Posts: 3123
Joined: Thu Mar 29, 2012 5:20 pm
Location: Salt Lake City UT
Isuzu vehicle(s): 83 Dsl LS Long Bed 4x4, 82 Dsl 2wd Short Bed 5 spd

Re: C223 Rocker Arm Wear - Excessive?

Post by Halden »

Siegfried wrote: Mon Feb 20, 2023 7:46 am There is a reputable shop local to me that can do the work but I wanted to ask is there a shop that has good experience with these engines that someone can recommend?
I doubt any automotive shop is really familiar with these save for the guy that does Jerry's work. Any good machine shop will do.
It's not pronounced "Ih-soo-zoo", it's pronounced "It-screws-you"
83 LS Long Box Dsl 4x4
82 Short Box Dsl 5 spd
05 Sonata with a standard
Post Reply