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AMC 258 Rocker fix - ticking noise

38K views 21 replies 13 participants last post by  jdhaas3  
#1 ·
My jeep has had a small tick coming from the valve train since I bought it. I changed the oil in my jeep for the first time since I have owned it this last weekend and the tick has gotten noticably louder now. I am running 10W-30 with some Marvel Mystery in it, I can only assume the PO was running heavier oil to help mask how loud the tick was.

This coming weekend I am going to pull the valve cover off and scrape off all the blue RTV that was used (no gasket) and check out the rockers. I know there is a long list of things to look as to what can be causing the tick, especially when taking over some persons previous project. I am just looking for a few of the normal culprits to check for. I am hoping it is just a worn pivot (seems fairly common when I searched) or something easy and cheap to fix.

We are also going to install the HEI, new plugs, check the compression and set the timing. Any and all advice is appreciated. Thanks in advance!:cheers2:
 
#3 ·
Not the rockers, but you might look at the the pushrods. While you have the valve cover off, turn the engine over and check the pushrods for looseness. There are different lengths used over the years. It is possible that one or more is short. The short pushrod can cause the click or tic you hear. That sound could come from a collapsed lifter also, where it doesn't pump up. If you start the engine up without the valve cover on, be prepared for an oily spray. It is amazing just how much oil can get all over everything and you... God bless.
Jon In Tucson
 
#4 ·
Also interested in this one since I have a bad tick when hot...

My wife and kids are going away for 2 weeks so I will have some garage time and looking for a :hahaha: small project.

How do you tell if the lifter is collapsed without pulling the head?

Just run it to pump them up pull the cover and check pushrods for looseness?

Should they also pump up if you prime it with the cover off? Not really thrilled about running it with the valve cover off.
 
#5 ·
Rockers and pushrods are easy to change. Had to replace a couple of each, recently when the pusrods bored right throught the rockers. It did it again within 2 or 3 days...turns out, the OP gauge was broke and I just assumed it had pressure...NOT. The second time it collapsed and destroyed a lifter.

So...I put in a new Mellings HV 4.0 oil pump with a 4.2 pickup, replaced the lifter and 1 rocker and pushrod. Filled her up wih 15w-40 Rotella, a new filter, and a new OP gauge...40psi cold, and once its good and warmed up, it idles with 18psi, and upward of 50-60 when getting down the road.
 
#15 ·
tell me more about that oil pump, you mentioned the 258 pickup, do you just buy a Mellings HV 4.0 pump, and replace the pickup tube? or? I have also got that "TICK".. have to go into it and find it .. figured on changing the oil pump also, so... and valve cover gasket leaks at the back, so.... and....
 
#6 ·
I doubt either of its going to cure it.
Lifters are weak and they allow a little extra clearance thus the tick.
You can here several of mine.
About the only way I've heard to cure it is replace the lifters.
Its on my todo list and actually plan on doing it when I change out to a 4.0 head.
All in good time right.
 
#8 ·
After a rebuild if I lost oil pressure like that I would be pulling it down and plastigauge the clearances because something is wrong...
 
#9 ·
Mine runs rather low pressure. Maybe 30 PSI on startup and 8 or 10 idling when warm. I had a knock that was VERY loud (like you could hear it a half a block away) at one point. Been running Rotella 15W-40 with a pint of Marvel Mystery Oil and the knock is basically gone. It runs fantastic. Without the MMO the knock does come back a little bit.
 
#10 ·
I would drop the pan and roll in a set of new bearings. You have at least one bearing that is ready to spin and possibly ruin a crank..
You can change all of them without pulling the crank.
 
#12 ·
Ok guys I had the same problem in my cj7 when it had an older 232 in it. I changed the pushrods and put in a melting high volume oil pump to. After all that I cam to the conclusion of the lifters being bad. I ended up rebuilding a 258 cause 2 pounds of oil pressure hot is just bad and after putting in that money was a waist of my time. Lifters are pretty easy to tell you'll notice it and I think I had some YouTube videos on my lifter noise I'll post it if I find it. If you have all these symptoms then I would just rebuil it cause chances are that she's wore pretty far, my timing chain was so loose it shaved the timing cover aluminum and Ruined all my bearings.
 
#14 ·
I have good oil pressure the whole time....according to the gauge...usually sits around 40lbs. This was the first oil change I did since changing the vehicle, I will change the 10w-30 out for 15w-40 this weekend with a little MM in it. Hopefully it isnt anything major when I pull the valve cover and check it out. At this point I just want to drive this thing, I can live with the ticking as long as it isn't horribly loud.
 
#17 ·
On my 304, I had (still have on a couple) of the rockers with some slight ticking. I pulled the passenger side valve cover off and found that #4 rocker arm was "loose". When the valve was closed, there was a lot of slop. I removed the rocker arm and found the end that hits the top of the valve was worn. (these were used arms.) To remove some slop, I removed the rocker arm, chucked up the pivot in the mill, and took off .020 and put it back together. The removal of the material on the pivot allowed the arm to tighten up to within specs. This got rid of my noise.

I am going to replace all of the rockers with roller rockers. I got lucky and the heads on my 304 are from a 1972 and already have studs in them. Rocker arms are a bolt on.

My rocker arm style is like this.
Image

Image


Where most are like this.
Image

Image
 
#19 ·
My jeep has had a small tick coming from the valve train since I bought it. I changed the oil in my jeep for the first time since I have owned it this last weekend and the tick has gotten noticably louder now. I am running 10W-30 with some Marvel Mystery in it, I can only assume the PO was running heavier oil to help mask how loud the tick was.

This coming weekend I am going to pull the valve cover off and scrape off all the blue RTV that was used (no gasket) and check out the rockers. I know there is a long list of things to look as to what can be causing the tick, especially when taking over some persons previous project. I am just looking for a few of the normal culprits to check for. I am hoping it is just a worn pivot (seems fairly common when I searched) or something easy and cheap to fix.

We are also going to install the HEI, new plugs, check the compression and set the timing. Any and all advice is appreciated. Thanks in advance!:cheers2:
Make sure your rocker arm(includes rocker arm bridge) bolts are tight or torqued to spec.
 
#22 ·
Pulled the valve cover and it was horribly dirty.



We pulled all of the rockers and cleaned them up as best we could. None of them were out of spec. I think they are just old and worn and need to be replaced.



I still have a tick but it isn't bad. I am going to wait as long as I can and just replace the cam/lifters/rockers/push rods all in one shot. I changed the oil from the 10W-30 to Rotella 15W-40 and that helped a little bit, just keeping the noise down. Jeep is running good though.

After we cleaned up the valve cover I noticed this scoring on the inside. The guy helping me said that isnt coming from my engine, that has to be from a previous engine because the noise mine is making is nowhere near what would be required to be doing this. What do you guys think caused this?

Either way, I am just ready to drive this thing. Just started leaking a little from the RMS, hopefully it isnt too bad and it can just go with it for a bit.