91 dodge spirit rocker arm


#1

Pulled the valve cover and the rocker arm was just lying there. Slipped it back in and it ran normal for a few days then fell out again. Didn’t seem to be adjustable, but maybe I just didn’t see it. Little help?


#2

I’ve got to say I have absolutely no idea what you are saying. If the rocker arm fell off, you can’t just slip it on again. I don’t know this engine, but rocker arms are either bolted down or pivot on a shaft.


#3

Not being a Chrysler expert or knowing which engine you have, I’ll float a couple of theories.
It’s likely this engine has floating rocker arms with hydraulic lash adjusters.

Overrevving an engine can pitch rocker arms off (common problem with the old Nissan Z cars) but I’ll assume flirting with valve float is not the issue. (Only mentioned this because a guy here runs a Spirit at the dragstrip)
This means the problem is likely caused by a faulty lash adjuster or less likely; low oil pressure or a restriction in oil flow to the top end.

A good lash adjuster should have a very firm feel to it if you try to depress it. If it feels mushy then it’s bad.
If one is bad you should consider replacing them all. While you’re at it inspect the ends of the lash adjusters. These were prone to the hard chrome wearing through with age, etc. and can disentegrate pretty quickly once the hard surface of the adjuster has given up. Hope that helps.


#4

ok4450,
thanks for the input - yes it is floating rocker. SOHC on a 2.5L, 4 cyl. Gently pressed the valve spring with a pry bar to replace it the first time. It had good tension.
I’ll investigate the lash adjusters as you suggest. As previously stated, I did not see where to adjust for MORE tension to keep it in place.
I question if the timing belt stretch (@ 80k miles) would allow the cam to be off just enough to let it go. But of course it would likely affect more than just one rocker.
I also wonder if build up on the valve seat could cause the critical distance to be enough less at the cam TDC on this valve stem to allow room to slip out. Restated - if the valve is sealing against build up, but not returning full length against the rocker arm, it won’t have proper tension to keep it in place with no cam pressure.
FYI -The spring looked good.
Maybe I need to pull the head. Yikes.
Really reaching here, huh!
Again, I’ll start with the lash.
Thanks, saf


#5

looked at the lash adjusters - also called hydraulic lifters. don’t see any movement in any of them - really wonder if they are to move at all. it doesn’t appear that they do. a couple pulled out easily and seem clean and good.
pretty sure the rocker arm just floats in between and do not adjust. they are held in place by the rounded tip of the lash rod into the rocker ‘cup’ and the valve spring tension. (which also looks good) don’t know. do you?
the motor has a slight tick and the check guage light came on after a while of driving around town. guessing this is overheating. don’t know cause mom doesn’t seem to understand ‘check guage’ means to look at them. gotta love her.
really a tough spot for me. could use help.
there is good oil pressure indicated on the gauge - thus i am deducting heat.
but the question is still - are the valves adjustable? can you tension down the rocker arms? (thinking this is location of the tick)
the other question remains - could the timing belt stretch have let the rocker out?
Note - it is recommended to do water pump and timing belt at this mileage.
thanks for any help
saf


#6

You have hydraulic lifters that take up the clearance between the rocker tip and the valve stem. The post on the other side has a light spring below the piston of the lifter. As the spring pushes up oil fills in behind through a check valve. When the cam lobe comes around the lifter post holds the end of the rocker up while the valve stem end pushes the valve open. As things expand and contract in the valve actuation mechanism, the hydraulic lifter will compress or expand to keep the valve clearance effectively at zero i.e. there will be no clearance between the tip of the rocker and the valve stem tip or the base circle of the cam lobe and the rocker contact surface.

If you have a ‘tick’, a hydraulic lifter is stuck; leaking down; is defective; or there is low oil pressure up in the head.

Another possibility for a rocker coming free is a sticking valve.

Hope that helps.


#7

Researcher,
thanks for the input. after cleaning up the lash/lifters and area, and putting things back together, the tick went away and is running good. zipped around with it and tried my best to make something go wrong. (really rodded it) feel pretty good that it didn’t. the guage thing was just low on coolant. simple enough there. just a coincidence to happen at the same time as the rocker arm problem. actually wonder if the heat made the valve stick a little and thus the rocker fell out. time will tell. oil change tomorrow.
just the same - thank you


#8

Having rebuilt many a dodge spirit in my lifetime here is my two cents worth. First, check the spring… OUT OF THE CAR! This is important as the spring might have enough pressure to “feel” like it’s good when it is actually out of spec. (this answer is the most likely in my opinion–>) Secondly, the Dodge Spirit in general have a bad habit of casting off their valve guide retaining rings. Leading to a valve guide sliding out of place and eventually keeping the valve from closing all of the way… LEADING to a rocker arm that is loose when the cam lobe is not pressing on it. Take care of this problem as soon as possible as it will very shortly render your engine useless. Third is valve guide binding. This will do most of the same things as the last one but can be brought on by heat as well as a million other factors. One clue in what you said “I used a crowbar to force the spring down and put the rocker arm back into place”. YOU SHOULD NOT BE ABLE TO DO THIS! The spring are FAR too strong for a crowbar to displace them without slipping and busting a couple of knuckles!


#9

toungewhunder,
Thanks for the input. I’ll have to investigate this some more. It seems to me that if I were to remove the retaining rings, washer and spring, wouldn’t the valve just drop through into the cylinder?
Maybe its time for my mechanic to have a look.
So far though, the car is running great.
saf