1999 XJ. New head, new valve train, new timing gears and chain. My problem is at TDC (compression stroke) both of the valves are open. It almost seem like when I torque the rockers down 19ft lbs., the valves tend to stay open. Almost like the lifter(cam followers) are not compressing. I've cycled through each cylinder and used a borescope on each one. None of them are fully closing. What could be the issue. Maybe I'm doing the timing gear wrong. Lined up the two marks on TDC Cylinder 1. Anyone have steps on installing the timing gear correctly and installing new valve train? New to XJs. TIA

 

Did you change the push rods at all? Are you sure the length is correct for new head? Was the head remanufactured, if so how much did they take off the deck? Was this accounted for?

 

A little history on this engine. The engine had a cracked head from overheating. So, I proceeded to purchase a remanufactured head and matched it with existing cracked head. New valve and spring already installed. While going through the engine, I found that it needed new parts like new valve train set, timing chain and gears, oil pump, resealing everything on the engine. Proceeded to replace the timing gears and chain while keeping true position of stock gears. the distributor was never removed by the way. Installed new valve train while checking and matching stock parts removed. The push rods were identical in length, lifters and rockers and rocker saddles were identical. Went through the procedure in installing via Haynes manual ie. timing on TDC cylinder 1 compression stroke and torquing to 19 ft lbs on the rockers while rotating to each cylinder. By inspecting what I have installed and using a borescope on cylinder 1 and 6, both intake and exhaust valves remained open and did not seat properly while rotating. This is also the fact on all cylinders. I did not know what was happening. So I redid every procedure via manual with the same result. My question is, Would the hydraulic lifters be stuck to where it didn't compress out of the box? They were soaking in oil for 5 days before installing. These are TRW brand lifters. I have seen videos that people have gotten stuck hydraulic lifters out of the box. Can this be the case. Any suggestions always appreciated.

 

My comment from the other forum:

How did you discover the valves were open? Did you attempt to start it, wouldn't start, checked and found no compression?

I'd suggest contacting the company that supplied the head.

 

Hello, Yes I checked all the valves per cylinder and the valves stayed open. No compression on each cylinder. I also used a borescope to physically check each cylinder and the valves remained open through cycles.

 

100% an assembly issue. Pushrods are too long.