Pinzgauer D24TIC

[ngoma]

Who would have thought that a little red paint could cause the camshaft to crack? Cheap humor, Sorry.

Seriously, could this be caused by warped head? The camshaft bearing bores might have moved out of alignment, making the camshaft have to flex as it spins.

[v8volvo]

Ouch.

When you remove the shim discs from the lifters, can you see spider cracks emanating from the center where the valve stem would have pushed through?

That breakage didn't happen spontaneously on its own, or likely due to cam bearing failure, strongly suspect a slipped front timing belt or timing gear.... did you remove the belt yourself in that photo? What was belt tension like? Cam sprocket tight on the cam? Water pump bearing spinning easy?

I'll second the advice to do a thorough examination of the front of the crank... starting with a torque check on the dampener bolt...

[Hecklebone]

The tension on the timing belt was fine. After the camshaft broke it was loose, the front pulley was coming out the front of the engine.
Yesterday I got the IP & PS pumps off, then the manifolds. Next up is the head. There are definitely dings in the lifter cups. Yes, WP turns freely.
Just guessing that the timing gear on the crank came loose somehow. When I get it all apart I will post photos.

[Nevadan]

You and I are in the same position. I'm going to remove the cam and inspect the lifters, among other things, this weekend. I'm thinking about doing a test as follows: after the cam is removed, remove the glow plugs and and use a rubber tipped air nozzle to pressurize the combustion chamber. If any valves are bent then the air will flow through, if not, then they should be fine and save me the work of removing the head. I may just remove the injectors and put compressed air in through the compression tester fitting to accomplish the same thing.

[Hecklebone]

Today i was able to get the head and crank pulleys off.
Looks like the timing cog somehow came loose.

[anders]

Wow, you sheared the locating key. How tight or lack of was the crank bolt?

[Hecklebone]

It was very tight. I could spin the timing cog before i loosened it with a 1/2" impact wrench.
BTW, i did not find any metal bits in the belt cover, so i have no idea if there was a key in there or not.

[Hecklebone]

Okay, i have decided to keep the D24 and reman my existing engine(if i cannot find one already rebuilt) and transmission. I will put higher strength parts from a 4HP24 into the HP22.

Where can i find all of the specs for the machine shop?
Any recomendations for where to get all of the parts?
Anything to upgrade while i am in there?
Should i start a new thread for this?

Cheers!

[v8volvo]

Odd, you're saying that even when the bolt was tight you were able to spin the cog easily? Friction alone should have prevented that if the bolt was tightened to the spec (~350 ft-lb). The key was there previously, you can see where it dinged the keyway in the crank when it got clipped off. The impact marks in the piston tops look surprisingly severe considering this incident happened at idle... It may be that rather than stopping immediately, as would happen with a sudden belt breakage, that cog let go somewhat more gradually and let the engine come relatively slowly out of time as it was running, permitting it to spin for longer and hit the valves more times, one guess anyway. Fortunately it sounds like you didn't tear up a cam bearing like the other guy's did, so head should be rebuildable.

All of the overhaul specs are in the Volvo green manual, or listed in VADIS, which is Volvo's tech info software. A factor which may make your situation a little more complicated is that your later-model engine evidently (from your picture) has hydraulic lifters, while all the earlier-type motors that came here in Volvos had mechanical valvetrain. For that reason I would probably want to make sure to cross-reference with the later info in VADIS, given that the D24T greenbooks only cover the older mechanical motors and there may be some updated specs issued after the hydraulic version was released. I can loan copies of either or both if you'd like.

Rebuild parts are available from various sources, most of them are pretty easy to get. Valves, lifters, pistons, rings, bearings, fuel injection components, etc are the same as used in a 1.6L TD (e.g. Golf, Jetta, Quantum TD motor). Most seals and gaskets are identical to those found in Audi 5-cylinder gas engines. A few parts are easiest to get directly through the Volvo dealer (e.g. vacuum pump gasket if needed, etc).

I've got a good reference for a local machine shop that is versed in these motors that I'm working with on one now. They're going to start going through a motor next week to build up for a guy's 745 TD from Texas that needs overhauled. We'll be doing some blueprinting, balancing, etc; I'm sure they would have no problem doing another one as well...

[Hecklebone]

Yep, it spun free while the font pulley was torqued to 350'#
From the indentations in the crank and cog, it looks like there was a smaller key in there. Maybe i should cut and fit a bigger key, or just weld it on.