So I took my rockers off Cylinder #4 tonight due to the one nearest the firewall being very loose. They look pretty warn to me for 93k miles but I really have no idea 'cause I've never removed them before on anything else. So how ugly are they?

Being as the valve looks to be of even height between the two I have to assume the lifter on the one is not pumping up. As gunky as this engine is...no surprise it may be clogged. I've the feeling they thought the oil cap was for adding oil only and the thought of changing it was quite obscure.

So what to pour down the rabbit hole? Add the option of MMO to the others shown in the picture, or add your own.

https://www.dropbox.com/sc/u9l0yl13jvgwnmq/ExV9fpjx-t

(Clicking on the images will show them in full)

 

MMO works well, as does Restore.

 

could be a collapsed lifter not pushing up on the push rod if everythin else is straight which would mean replacin it

 

Thanks guys, threw mmo in. So...how bad are the things the rockers ride on?

 

Those rockers and pivots look pretty bad mate. You should think about changing all of them. Some people have lucked out and got a set of serviceable rockers, pivots, and bridges from the junk yard so you might give that a try before buying new parts.

Soak a piece of rag in MMO and push it down on top of the tappet with a push rod and see if you can clean some of that crap off the top of the tappet. If it seems to work try it on the other tappets. Make sure the rag is long enough so you can pull it out of the hole.

Edit: Make sure the pushrods aren't clogged up. Looks like you weren't getting oil to the rockers. You may want to pull the rest of the rockers and check them, as well as the pushrods and tappets.

 

A couple of checks you can make;
1. The amount of travel (cam lobe lift) on the pushrod should be .254"
2. With the valve closed there should be from .020 to .060 preload on the pushrod. In other words when you install the fulcrum & rocker and torque it down the push rod should depress into the lifter .020-.060".

IF the fulcrum block is worn to the point that the preload is gone a "down & dirty trick" is to file the base of the fulcrum block until you get some preload.

Another point; If this engine had been run with thick oil due to additives (the gunk suggests that it may have been) it would take up to several minutes (or longer) for oil to get to the rockers every time the motor was started cold. Thick oil will KILL an engine,especially the valve train.

Disregard the remarks about the lifter not pumping up....you should have preload ( the amount I mentioned) with the engine off and lifter bled down. This preload comes from a spring in the lifter so you should feel it when you push down the pushrod. If you do not feel any spring motion your lifter is bad.

 

CCKen, I ran with cover off and am getting flow up all rods now. I had just recently purchased vehicle and changed oil. Old stuff was pretty nasty and generic filter felt totally clogged so who know what history is...

bigbadon, I'm guessing the cam lobe lift test would let me know if my cam needed replaced. otherwise it seems like lifter is only other option. Currently while loose the rod is still being held in place and operating to at least some degree. so I think playing with fulcrum may be unnecessary and possibly even unwise should the lifter get ungummed and start behaving properly again (assuming lobe test comes out good). I will play with lifter a bit both with mmo and cleaning and pushrod to see if it has some pressure or if I can un-gum it.

As you know I am also dealing with low oil pressure and a possible cracked head or head gasket. While I think it is a good idea to maybe disassemble/view/clean/apply assembly lube/reassemble the rocker shade and push rods, I think replacement at this point is not wise. This being due to the fact that I may end up getting a Clearwater Cylinder Head that would have all parts new anyway if I can't find or decide not to go with a jy head.

Is that sound thinking or am I leaving something out of the equation?

 

If the pushrod is being held captive in the rocker, button it up and get a new/rebuilt head coming. Don't dilly-dally on changing the head.

 

have you checked the steering stabalizer That might be the easy fix.

 

My bad, I meant there while there was excessive play between rocker and push rod, the pushrod was still "in position" and not so loose that I feared it may totally escape the rocker, not that it was captive.

 

You are correct assuming that it is stuck that is why I said to pry it down and let it spring back. If you feel it snap back that is telling you that the lifter plunger is against the cir-clip that is the max lift,it cannot pump-up any higher. If at this point you still have play it has to be one of 4 things; worn cam, worn face on lifter, worn fulcrum or stuck valve.
The important thing to know is that when checking under static condition (engine off) the lifter is held up to its maximum height by a spring. With engine off and lifters bled down you should be able to feel this stroke, when running, oil fills the void under the plunger making it uncompressable

 

lol, my wife was saying the stearing felt a bit sloppy...on the bright side the tire pressure has remained steady

 

Thanks that cleared it up for me a bit and give me a cleared path forward. While my fulcrum/pivot is obviously scratched up, it doesn't look any more worn on the intake side then the exhaust which appears to have proper seating of push rod.

I laid a short straight edge along the two valve stem ends. I pressed directly above the exhaust(good) stem, to keep it square with flat stem end and then tried to see if the other side rocked at all. I felt no play. Is that a worthwhile test of the valve sticking? I figured to be causing trouble here it would have to be sticking open right? Or would I need to have Cylinder #4 at TDC to make this assumption work?

 

If you had a dial indicator you measure & compare the valve stem height. A compression test would tell you more. can you feel the internal lifter stroke? Complete hydraulic stroke of lifter is only a little more than a 1/8" Make sure the lifter is bled down first by using a pry bar to push down on the pushrod end of rocker arm. After you evacuate the oil out of the lifter the spring is the only resistance you should feel and you should feel it go down about an 1/8" and spring back up. Since most cars have adjustable rockers (small block chevy) the fulcrum wear can be compensated for...not so with jeep but filing base of fulcrum block will accomplish the same thing.

 

You have some SERIOUS coolant in your oil man. Check your headgasket/head for leaks ASAP.


Your bearings may be toast by now too. ouch..