loose pushrod....any easy fixes/ diagnosing true problem?

panisher57 · Newbie Joined: 28 Jun 2012 Posts: 1 143.34 points

i had purchased an 85 c-10 rwd with a gen1 350(206-400) and then engine has been modified with aluminum edlebrok heads. i have aluminum rocker arms. i was told it runs at high compression not sure of the ratio, but i i have a loose push rod. i was told its more than likely it could be a flat cam i prolly going to have to do a cam and timing chain in it. Looking to see if i can get an easy fix an reset the valve some how just for a short term fix until i can find a place to pull out my engine and get better look

10sec.et · Posted: Thu Jun 28, 2012 9:42 pm Post subject:

tighten the adjusting nut. if its just a flat cam, you should be able to change it without pulling the engine.

SMOKEmUP · Posted: Fri Jun 29, 2012 3:37 am Post subject:

Check the oil filter for signs of metal.

Paul P · Posted: Fri Jun 29, 2012 10:10 am Post subject:

If you have a magnetic drain plug that should tell you pretty quickly if there is metal in there. Just pull the valve cover and watch the rockers move if you see that 1 or more really are doing much and the pushrod is loose you have a flat cam. This is more of a common thing with older flat tappet motors because the EPA is taking everything they need out of the oil to protect the catalytic converters.

Big Dave · Posted: Sat Jun 30, 2012 10:39 am Post subject:

I wouldn't drive it if your cam is going flat.

You have a hardened steel lifter that is turning your softer cast iron cam core down just like a cutting tool on a lathe, all of those metal shavings are going into the engine destroying it. You will be needing a new crank as well as the small metal particles that get through the filter embed themselves in the soft babbitt of your bearings. The filings also get thrown up on the cylinder walls by the crank churning the oil so you are grinding the wall surface as well requiring an overbore.

Once a cam starts to go flat nothing can stop it as the hardened surface is only a half dozen or so molecules thick if Nitrated (the way GM does it) and few thousanths thick if induction hardened which is how some of aftermarket does it (if they do anything at all).

Big Dave