i got a 1990 f150 with a 4.9 and i have a rocker that i can shake the crap out of just through the oil fill cap any ideas on what this could be? i think its just a loose rocker and if so do you have to set valves or just torque them to 20 ft.lbs

 

I'm not real familiar with the 300-6, but I thought they were shaft style rockers, which shouldn't move side to side without force(springs and washers hold them apart) and they shouldn't twist any.
Movement up/down against pushrods and valve tip, should be minimum if any.

Pull valve cover and check for bent pushrod or see if the lifter is bad and not keeping tension on pushrod.

 

i was thinking that too because this truck sat for 5 years so i figured maybe a seized lifter but didnt know if thats common but sitting that long wouldnt suprise me if that was it be cause it sat compressed

 

FYI for you guys, the Ford 300/4.9 does not use shaft style rocker arms. They are either ball and stud or pedestal mount, depending on the year. Most are simply torqued down and that is it for adjustment, although some of the earlier models (carbed) did have adjustable rocker arms. Your engine shouldn't have the adjustable type and more than likely pedestal mount rocker arms.

Does your truck run? When was the last time it was started? If it hasn't been started in a long time, there probably isn't any oil in the lifter and that can be causing the slack you feel. When you go to start the engine for the first time, you need to put about an ounce of Marvel Mystery Oil in each cylinder through the spark plug hole and you really should prime the oil system. This is easily accomplished by removing the distributor and using either a long extension with the oil pump rod at the end and a drill, or an old distributor with the cam gear removed. You'll feel plenty of resistance on the drill when oil has been picked up by the pump and you should let it prime the engine for about 45 seconds to a minute. If you are comfortable doing this, you could even rotate the engine around by hand once the oil has primed to ensure everything is nice a lubricated for when you go to start it. Just make sure to index your starting points on the crank and the distributor before you do any of that. If you decided to turn your engine over once you have prime, you'll need to turn the crank two complete revolutions to get your cam back where it needs to be so you can stab your distributor correctly. Make sure to time the engine with a timing light once it has warmed up.

 

yes it does not have shaft style rockers and yes it starts up every crank and so does that mean that im just going to have install new lifters?

 

Does it rattle? Does it sound like it has lifter issues?

 

yes it rattles terribly but you can see the rocker arm through the oil fill cap spazzing out and shut it off and move the rocker quite a bit

 

I was thinking they were still like the older 240/300 with common shaft.
That's cool they are pedistal rockers now.
Hmmm
Def bad lifter then. Or bent pushrod.
I concur with the marvel mystery oil. Or seafoam in the oil.

 

Until you take the upper plenum and valve cover off, you aren't going to know what all is wrong. It's possible that it might have backed off and that you just need to torque it back down. That has happened quite a few times to FTE members that I've read about, so you might get lucky. On the other hand, you could need a new pushrod, rocker arm, fulcrum, and lifter. Heck, you could even have a dead lobe on your camshaft.

 

ok thanks guys i will pull the valve cover and see whats going on.

 

i got the valve cover off and the rocker bolt was tight so i pulled the rocker off to see if the pushrod was bent and i cant pull the pushrod out so im guessing its bent in the bottom witch had to of been caused by a seizeid lifter? what do you guys think?

 

Unfortunately, it looks like you'll need to pull the lifter cover off now and take a look. Once you have done that, then you'll be able to narrow it down to a bad push rod, bad lifter, or a bad cam. That's pretty much where you are at. Take some pics and post them up for us.

 

pulled the lifter plate off and come to find out its a bent push rod the thing is bent at 45 degree angle and the lifter is seized so im guessing thats what caused it and how do you upload photos? you got to see this thing!

 

I'd be concerned about the potential for a bent valve now, since pushrods aren't exactly easy to bend. There was definitely piston to valve contact so further investigation would be wise.

 

I'm going to have to agree.