valves adjusted adjusted adjusted....and still rattle

[watermellonI]

I hve adj the valves on merc 3l (thanks Don S and Reel Poor) had to go back and adjust again,(went on high side lost compression and had to start over)

anyway got her runnin, turned down idle,(after breakin needle valve) ((would not seat)) and still have a rattle that increases with throttle sounds like its comming from #4 valves.

hve a friend who says wrist pin on piston, anything easier to check?

oil pressure good, spark good, timing? ...help

 

[Coors]

Re: valves adjusted adjusted adjusted....and still rattle

Pull the spark plug wire while it is running, and see if noise goes away.

 

[watermellonI]

Re: valves adjusted adjusted adjusted....and still rattle

thx coors, but no luck pulled no 4 no change, i ll try that on all cyl, seems to stop when oil pressure is increased but once oil is cycled in it comes back, oil pressure seems fime runnin around 40

 

[watermellonI]

Re: valves adjusted adjusted adjusted....and still rattle

pulled plug wire on 1 and noise got quiet re adjusted valves still rattles

 

[Bt Doctur]

Re: valves adjusted adjusted adjusted....and still rattle

describe your valve adjustment .
you shoud be up to temp, loosen one rocker nut till it clacks, tighten down till it`s gone and then 3/4 more,slowly.

 

[Coors]

Re: valves adjusted adjusted adjusted....and still rattle

describe your valve adjustment .
you shoud be up to temp, loosen one rocker nut till it clacks, tighten down till it`s gone and then 3/4 more,slowly.

Yes, start here again. I have torn down hundreds of engines, and only 4 times was it the wrist pin. And never on a small block mopar, as they spent the extra $20 to install full floating pins, un-like gmc.

 

[RCSConstruction]

Re: valves adjusted adjusted adjusted....and still rattle

pulled plug wire on 1 and noise got quiet re adjusted valves still rattles

That sounds more like a rod/piston issue.
When you pull the plug wire it stops the combustion, it wouldn't quiet a mis-adjusted valve.
There is a phenomenon called "piston slap". Does it get quieter as it warms up?

 

[Coors]

Re: valves adjusted adjusted adjusted....and still rattle

yeah, but piston slap, most people can't hear
To check that; check compression when, cold, then recheck when hot
Or do a leak-down test right off.

 

[RCSConstruction]

Re: valves adjusted adjusted adjusted....and still rattle

yeah, but piston slap, most people can't hear

I had a 2000 slaparado (silverado) that had what they called CSK. Cold start knock, aka piston slap. Mine was so bad it never went away and made my idle screwy. Lemon lawed that sucker.
I can hear a slaparado from 30 feet. tick,tick,tick......
Not real common on the 350's (vetts had it) but plagued the 99-03 Chevy's.
I am a big freak when it comes to noises and have noticed that you hear allot more from a boat engine (it's right in your face) than you do in a vehicle.
Maybe he is just sensitive to the normal valve train noises like I am.
Good Luck in whatever it is.

 

[watermellonI]

Re: valves adjusted adjusted adjusted....and still rattle

thx fellas, i don t wanna adjust while running ( looks like ill have to) been making adj per directions, adj,run,adj
loosen to lash, remove lash, 3/4 turn,

the noise gets louder when i tack it up, wasn there before, i am sesitive to the noises engines make and i ve learned what just about all of them are, this one is almost a hammerin sound and seems to be comin from the top of motor, will pull 1 pushrods to see if they re bent today

could this have anything to do with timing?

I just aint gettin it i can hear the rest of the tappets and rockers rollin smoooth as can be.

 

[piperdriver]

Re: valves adjusted adjusted adjusted....and still rattle

The definition of insanity is repeating the same action over and over again hoping for different results. As stated before, valve train noise will not differ with the removal of the plug wire. What the removal of the plug wire WILL effect is a Rod bearing or a piston wrist pin problem. Nothing in the valve train will be effected. One rod bearing may not show as a decrease in oil pressure. The first thing I would suspect is a rod hammering, and a far second, a piston wrist pin problem.

 

[watermellonI]

Re: valves adjusted adjusted adjusted....and still rattle

a gallon of kerosene and a flare are lookin pretty good right now.

 

[watermellonI]

Re: valves adjusted adjusted adjusted....and still rattle

can i disable #1 cyl , pull push rods and label, and baby motor for temperary fix? pulling intake rod and leaving exaust rd to open position

 

[piperdriver]

Re: valves adjusted adjusted adjusted....and still rattle

You can of course do what ever you want, but I would not say that this is not a good course of action. You risk completely damaging the engine. If you want a "cheap" fix don't run it any more. You may get lucky and be able to polish the crank, and slip a now insert in the #1 rod. Of course we are assuming that it is in fact a rod bearing. What you are describing is pointing VERY strongly to that. It is going to be work either way, but you may get by on the cheap if you pull it NOW.