" > wrote in message
oups.com...
> I'm back with an update. Thanks for all the help so far. I tried
> losening a couple of the rockers with the motor running as suggested
> but it didn't work; still no oil even after 30-60 seconds of running
> like that. I also hooked up a trusted mechanical oil pressure gauge
> and found that I do have 50psi at cold idle, so I'm ruling out oil pump
> and any serious bearing trouble.
>
> Here's a little background that may help the experts. This all started
> when I took the truck on a trip much longer than we normally use it.
> Typically, on the farm, it doesn't run for really more than 30minutes
> at a time, but I was helping my brother move and had to drive it on a 3
> hour trip, including some highway. On the way, after about 2 hours, I
> started hearing a ticking in the motor. It's hard to describe the
> noise; it was louder than the tick that comes from a loose rocker, but
> not as loud and deep as a connecting rod problem. It's frequency was
> dependant on RPM, but the noise did not get louder if the motor was
> revved up; it just ticked faster. I had no idea what the cause was,
> and since I was far from home anyway I figured the motor was toast and
> I tried to make it as far as I could. It made it the rest of the way
> to his house and back, running the same way.
>
> I started working on the motor and found the spark plug on the #5
> cylinder was smashed flat on the end, and that with a new spark plug
> the piston was not working right; it skipped and removing the spark
> plug wire from that spark plug made no difference in how the motor ran.
> I pulled the valve cover and found only a tiny amount of oil flowing
> down the rockers when it was running, went farther and pulled the
> drivers side head and found the exhaust valve on #5 was broken - 1/2 of
> the outer ring of the valve was gone and the piston dome was pretty
> lumpy. No pieces inside.
>
> I had the head checked and fixed, put it all back together. Now the
> motor runs very smooth, but the loud ticking is still there. With the
> motor running, I loosend the rocker on the #5 exhaust valve, and the
> noise got less and less; with no tension on the pushrod tube (it just
> going up and down but not compressing the valve, it was almost gone -
> the loud ticking noise (normal valve ticking was going on though cause
> it was loose). As soon as I slightly tightened the rocker the ticking
> started again. I pulled the intake off but everything looks ok, but
> what do I know?
>
> So - what does this mean? Can hydraulic lifters go bad and cause this?
> Could a bad lifter keep oil from going to the top of the head?
>
> Oh, and by the way - when I took the distributor out I think I know
> where the idea about the distributor came from. The channel in the
> rotor housing that passes oil from the pressure port behind it to the
> lifter ports on the side is not a consistent shape; one side narrows
> down and is much smaller than the other side. I think if it was in 180
> degrees backward it could impede the oil flow, but it didn't look like
> it would block it completely on my engine. It was in 'wrong' from what
> I could see - the narrower restricted side was towards the oil pressure
> port in the block.
>
> Tomorrow I will replace the lifters and spin the oil pump with a drill
> to make sure oil is getting up there. If that doesn't work I do not
> know what to do next.

While doing all that, ensure ALL holes are open all the way thru the
pushrods--no crud, no battered ends, as oil MUST flow thru these. Note that
those short 30-minute running sprees cause undue wear on lubricated parts;
and these cold sprees can also cause oil holes in push rods to stop up ( as
well as oil return holes in the heads and internals of lifters ) due to
constant cold running & oil never heating enough to let the detergent do its
cleaning. Ever tried to wash grimy hands with bar soap and cold water?
Then try it using warmed, detergent engine oil: you may be surprised how
well it cleans!
your questions: yes, hydraulic lifters can go bad and cause
this.
...and: Yes, a bad lifter can keep oil from going to the top of the
head--they are what actually what pump oil thru the push rod holes to the
rocker arms.
HTH, s