loose engine rod

[Rusted]

What does it mean when I can push a rod down into the engine with just a little thumb pressure? It springs back up, but it does not take much force to push it down. The others feel like they are solid, this one is not right. What is down there that would cause this?

I-6 engine out of an 83 CJ7. 4.2L with about 220,000 miles. Still has good compression across all cyls

 

[Brett]

Push rod for the valves?

 

[Rusted]

I always thought it was the lifter down there, and it was physically connected to the camshaft. From an old book I found a diagram that shows a "tappet". Are lifters or tappets spring loaded? Is it a broken spring, that is what it feels like

 

[Brett]

I'm still trying to figure out which part you are talking about....lol

 

[gijohn40]

I'm not sure but it could be a hydrolic lifter which isn't keeping the fluid in as you push the rod down the fluid is escaping... how far can you push it down? and does it go slowly or pretty quickly?

 

[Rusted]

It moves quick, as quick as you push it, and probalby at least 1/2" of travel.

 

[mwmx54]

in most cases it will go cam, tappet, shim, top of the valve, retainers to hold the, in your case probably broken spring down, then the other side of the spring will be pushed against the head..

 

[bobmed]

it's probably a broken spring in he hydraulic lifter (tappet)
I was changing out my cam and lifters on my Bronco for the same
problem.
Thats when I found out my cam bearings were wiped out.
New lifters are'nt very expensive, I think about 3-4 dollars each.

 

[gijohn40]

it's probably a broken spring in he hydraulic lifter (tappet)
I was changing out my cam and lifters on my Bronco for the same
problem.
Thats when I found out my cam bearings were wiped out.
New lifters are'nt very expensive, I think about 3-4 dollars each.

Exactly what I was thinking... 3-4 dollars for the lifter... $200 to get the head off and find all kinds of things wrong.... hope thats not the case!

 

[Rusted]

No way to replace a tappet without pulling the head is there? That would be way too easy right?

 

[Greg]

Sounds like a collapsed lifter, normally the lifters are pretty darn hard to compress. If you're going to change that lifter, you really need to change the camshaft and the rest of the lifters too. Cams & lifters develop wear patterns in them... just as you wouldn't mix diffrent gear sets, don't mix camshaft parts. Or you'll have to do it all again.

Sounds like a good time to upgrade to a better camshaft!

 

[Greg]

No way to replace a tappet without pulling the head is there? That would be way too easy right?

Nope... :-\

 

[Caleb]

Sounds like a collapsed lifter, normally the lifters are pretty darn hard to compress. If you're going to change that lifter, you really need to change the camshaft and the rest of the lifters too. Cams & lifters develop wear patterns in them... just as you wouldn't mix diffrent gear sets, don't mix camshaft parts. Or you'll have to do it all again.

Sounds like a good time to upgrade to a better camshaft!

this was my same thought but I don't know a ton about the internals so I didn't say anything

 

[Rusted]

That is what I figured too. I was hoping to her someone say "rent the tool for $8 and you will be done by the afternoon", but I am just not that lucky.

 

[SundancKid]

I hate to ask this, but is there a reason you pulled the cover to look at the lifters?

I ask because some lifters bleed down pretty easy. It doesn't really matter because the oil pressure pumps them up as the engine runs. Even more, some lifters are designed to bleed down quickly at low RPM/pressure to make the cam profile appear smaller then it really is for better low RPM/Idle.

Was the lifter making noise? Was the engine performing poorly? Does a vacuum check indicate valve issues? If not I see no reason to mess with it. If it aint roke don't fix it. If you have the engine torn down then replace 'em all anyway.