, on a 4-stroke engine you will go past top dead center twice with one revolution of the crankshaft.you were going to have to be sure that it is on the compression stroke and not the exhaust..ugh.. I'm terrible at explaining things. Look up on the Internet locating top dead center on a 4-stroke.

And if you set your cam out of phase during reassembly I would be careful about rolling it over until someone chimes in that knows more about these.

Valves are stuck open or not sealing, why? Lord knows...

From what I read so far, lapping is not enough for the valves in our diesels. The valves and seats should be ground by a machine shop, or you will have compression leaking past the valves.

Can't imagine that OP has enough compression leaking to show up as zero on a compression tester, but I would not be surprised to see this engine producing low power due to the valves. Just my 2¢.

Something has to be holding the valves open in this case. If you have new rings, new cylinder sleeves, new head gasket, and everything is torqued correctly, there is nowhere for the compression to go but out the valves. I am assuming you have the glow plugs installed.

Roverswap, what all have you done for this rebuild?

Start with the basics. Are the accessories on the front of the engine turning? Try cranking with the oil cap off and make sure the cam is actually turning?

Definitely a leak down test next. Interested in seeing the results on this one.

Zero is a really low number. You should be able to develop SOME pressure by turning the motor over by hand. You should hear some hissing and puffing as the exhaust valve opens, even at a few RPM.

Set the harmonic balancer to zero with the cam marks lined up. Remember to concentrate on the cam marks. Then look at the harmonic balancer. Your number one cylinder is then at top dead center. Inject some air into the number one cylinder. You will hear where it is leaving the engine.


I am going to take a wild guess. When you set your valves. You did leave a gap between the valve and the rocker arm? This is not a hydralic system. where there is a preload on the lifter.


Whenever I got a head back from a machine shop I inverted it on a bench and added some very light oil around the valves. I expected it to still be there hours later. Or the valves where not tight. I expect what you find with the number one cylinder will be consistent with the other cylinders.

Nobody watched the clip the OP posted way back in Post #5? The engine clearly has no compression.

Loosen rockers so that the valves are closed, then roll it and see if you have compression.

I just watched it. He said he used 3 different compression testers.

5 cylinders that have no compression when you can hear the compression when the engine is turning? I'm thinking he used 3 defective, broken, or incorrectly installed testers. The needle doesn't move at all. You can hear the compression when he cranks it.

Go back and watch again. There should be a very distinct change in starter tone every time it comes up for compression on the cylinder he has the compression tester on.

The starter does slow down when it spins over the cylinder with the tester installed.

Barely. With as weak as that starter is, it should have a VERY noticeable change in pitch/cadence. Even on the 140PSI Jeep engines, they have a very distinct tone on each compression stroke. That's clearly missing here on an engine with 2x-3x the compression. Something funky going on.

Hah I feel stupid, had I watched the video I'd have seen everything was rotating.

Place shop towels over the injector holes when you crank it. You should be hearing a "puff" and the towel should move when you crank it if it has any compression at all.

Without knowing what exactly you are considering a "rebuild" people are just shooting in the dark.