I'm confused. I have a 98 5.9 magnum that I was doing a leakdown test on before dropping into a 71 Dart. The biggest problem was that I had 100% leakage on number one cylinder. Took the head off and had carbon under the valve seat so I cleaned the cylinders, lapped the valves and put the heads back on. Checked the cylinders and had between 4-6% leakage on all cylinders, so I installed the lifters, pushrods and rockers. Again I had 100% leakage on number one. I replaced the lifters on that cylinder and still have the problem. I can loosen the rocker arm and the valve will close, so it's not a valve sticking. What am I missing here?
Magnum roller lifters
- Thread starter 68coupe
- Start date
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Maybe the lifter is stuck full pumped up?
Well, even fully pumped up shouldn't the valve close? The other lifters in this engine will compress about 1/8" when you push down on the rocker arms. I have two other sets of lifters and when I put any of those in they also will keep the valve open. I have checked the rocker arm and push rod. I can't figure out why some of the lifters will compress and others won't. All of the lifters are from 92-98 Magnum engines.
Marcohotrod
Well-Known Member
are all the pushrods the same length? did you replace those 2 lifters with new or used? if the 2 lifters on cylinder 1 are fully pumped up and will not compress, U need to get some oil out of them
Pushrods are all the same, rockers are the same. I replaced the old lifters with used lifters that have about 60k miles on them.
Marcohotrod
Well-Known Member
and so the lifters on cylinder 1 are fully pumped up and do not easily allow the plunger to push down, that is the problem. disassemble them or put them in a vise or whatever to get some oil out
Shainesboostin
Well-Known Member
Bleed the lifters I would guess.
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