I have a ticking in the motor (240 I6) that I believe is valve train related, but my manual says it has hydraulic lifters. Is it common to adjust valve lash in these motors?

 

Not common to have to readjust. Once they are adjusted, they are good to go. You may have a weak or sticky lifter, or a rocker may have loosened up. Change the oil and add a quart of Marvel Mystery Oil in place of a quart of oil. Check your rocker arms to make sure they have not loosened up.

 

I have the exact same issue with my I-6 240CID. But how do you determine if the rocker arm has "loosened up?" From what I read in the Chilton's manual, it is a fairly involved process requiring a tool that "bleeds" the hydraulic lifters before checking the gap between push rods and rockers. Some manuals indicate a torque value for the rockers, but when I tried that, they all turned easily, far below the listed torque value. I think all that happened was I depressed the lifters by forcing fluid out.

Can anyone out there please educate me on this process? Thanks.

 

Think I'll try out the MMO. Saw some reviews that said it may be some pretty good stuff. I just hate the thought of screwing with the adjustment.

 

Nice thing about the 240 is that the lifters are easy to access. Pull your valve cover, and side cover, and you can get to everything. Cheers.

TommyJ

 

Gmills, Please post whatever you learn to this thread. This is a great forum and we all learn a lot from each other. Thanks.

Keith

 

Im not a big fan of "liquid mechanic", but the mystery oil has, for me, worked on several engines with your symptoms. good luck!!

 

It's been a long time since I've been able to tinker with an old truck. I think I've found a new hobby. I changed the oil yesterday, and added the MMO. I'm also not a big believer in additives, but thought I'd give it a shot. The motor runs really good, but could use an overhaul soon. It has lots of leaking gaskets. I crawled underneath for the first real good look, and found oil starting at the front of the oil pan all the way back over the tranny (plus a lot of rusted our areas that need attention). I figured it couldn't hurt to try the MMO to get rid of the tick. I'll post again with the results.

 

gmills and all. Early 240 & 300 I 6's you can adjust the hydraulic lifters. These engines have rocker studs that are straight and a locking type nut that holds its position where you leave it. The other/later have a rocker stud with a taper and the nut has a corrosponding taper, these nuts will screw down by hand and need to be tightened on the jam/taper. These use standard, .060 longer and .060 shorter pushrods. This is what wagonerkl was referring to.

 

How I adj mine. What you are doing is positioning the plunger in the lifter body to depth it is designed to run at. Warm up engine, remove valve cover, hook back up what you need to run the engine, start engine and let idle. gmills on yours (anybodies) feel the rockers one at a time, you should feel the one that is ticking. I use a 3/8ths ratchet and a 5/8ths six point deep socket, least likely to slip set up. Loosen the rocker nut a bit and the clack shouild get louder, let clack about 10 secs, tighten the nut slowly till clack just disapears. That is basicly zero clearence between the rocker and valve stem. Your adj is ONE FULL TURN down of the nut. You have to do it in 1/4 turn increments as the engine will shake wickedly ( its holding that valve open) for 10 to 30 seconds then the engine will idle smooth again. You need to do this 4 times to get your full turn down. Any ?'s ask and I'll try to add what you need.

 

Thanks IICAP! The MMO isn't doing much after 50 miles. I'll get a gasket and do the adjustment.

 

Well, pulled the valve cover and found the source. I have a severely bent push rod.

 

gmills, glad you found the pushrod, did you adj after installing new or straightened pushrod as I had outlined earlier. Is this the same truck/engine with your thread about 240 with 11 MPG, if so adjust all the lifters as there maybe some others not right and possibly to tight and keeping valves open minutely yet not causing a missfire. Wondering about bent pushrod? If truck is new to you and not knowing its history, who knows how it was used or abused.
IICAP

 

yep, this is a new truck to me. I've got the new rods on order. I'm gonna replace 'em all. A friend told me I should look at the lifters too. How do I identify a bad lifter? Is it common to bend a push rod without other damage? I'm curious how the rod was bent in the first place.

 

gmills, if you have not removed all the pushrods or changed the adj yet do the adj backwards, engine warm and idling loosen the adj nuts one at a time till just hearing clack then tighten to quiet the clack only, YOU WANT TO NOTE and hopefully find that the clack appears after you have loosened them 1 full turn of adj nut. To some this all may be a waste of time, but your are trying to DIANOSE A PROBLEM. You don't know what someone has done already to this engine, maybe their all way to tight, who knows.
Was the bent rod from an intake valve? if this truck sat for a few years with gas that turned varnishy and it got running on some of that gas that varnish will lock the intake valves to the guides, it won't open and you get a bent pushrod, this is a possibility but I think you would have more than 1 bent.
Finally, the pushrod may have gotten bent by overreving the engine. For an everyday driver, you don't want to sit there and hi rev/scream an engine. It's not necessary and you risk very serious damage in a matter of a couple seconds.
A long response but another on this thread said they would like to learn all they could about this subject.
If it's apart already, well you might want to use this scenario another time.
Good rule of thumb ALWAYS especially with engines you can't adj lash or lifters.
Lifter, push rod, rocker and pivot ball should all stay together and be put back in where they came out, drill 12 or 16 holes in a piece of 4x4 big enough to hold the lifters and an adjacent hole for the pushrod and stack the rocker, pivot ball and nut over the pushrod.
Again longwinded, but don't want you to have to guess at what I'm saying
IICAP