Valves not closing

[martyodell]

Hello everyone, I need help figuring out why intake and exhaust valves on a 2006 FE350 won't completely close. Problem was found when I noticed oil getting in fuel pump. Checked compression, it is at 150lbs. Engine will run until oil fills up pulse line to fuel pump.

[kgsc]

You can check valve clearance but with 150 psi I would think they are closing. Is this a lifted cart? May have too much oil in it. Also make sure the pulse tube is elevated.

[martyodell]

I did a leak down test and found air coming past both valves. Valves are hydraulic with no adjustment. At TDC there isn't any valve clearance. Oil level is good, just a bit below full mark, and cart is not lifted.

[Jimmie]

Check your pulse line to fuel pump for sags. The line should be uphill all the way.

[martyodell]

The pulse line is uphill. Why would there be no valve clearance?

[kgsc]

Hydraulic lifters. If it is letting air past the valves the lifters may be stuck or the rockers may be too tight. If you just want to check the valve seats, loosen the rockers until you do have some clearance on a non lifting point of course and do your leak down test again.

[martyodell]

The rocker arms have no adjusters on them. Is it possible that pressure is getting past the valves and creating to much pressure in the block. As I mentioned before this cart does run with the valves this tight.

[kgsc]

Originally Posted by martyodell

The rocker arms have no adjusters on them. Is it possible that pressure is getting past the valves and creating to much pressure in the block. As I mentioned before this cart does run with the valves this tight.

No adjusters, thought about that after I told you to do that..

And the answer is yes, too much case pressure can push oil into the pulse tube which I believe is your problem. Check the case breather tube to the air box and make sure it is not blocked.