Need help fixing valve ticking!

[Thor]

I have a 89 chev 6.2, and recently put a used 6.2 out of a 82 chev blazer. This thing has developed a ticking which sounds like it under the right side valve cover. I can pull off valve cover, but what would cause this tick if valve are self adjusting? Could there be a weak spring? Any ideas on what to check? how to fix? Thanks guys.

[gmctd]

That '82 will have cast rocker arms - pull the 'cover, bring each cylinder to TDC, wiggle the rocker on each valve at TDC, see which one(s) is looser than the others - pull the shaft(s), look for grooved shaft(s) and rocker(s) on the bottom side at the fulcrum pivot points

[Thor]

Do I have to pull a injector in stall a dial indicator to find exact TBC, or is there a easier way to do this. Thanks

[gmctd]

Easiest way is to rotate the crank till you see the exh valve on any cylinder closing - each cylinder fires at 90deg intervals - 1-8-7-2-6-5-4-3 - note the position of the timing marker on the HB in 90deg intervals to get very close to TDC for each cyl - both valves will have max clearance within....what? 10deg, plus\minus - you're looking for a lot of clearance, comparatively - both valves are dead closed between the exh and intake strokes, most anywhere in the compression stroke, at the beginning and most of the way thru the power stroke.

[sidehackbob]

I know you want to see whats inside your 6.2 but first...

Try the ATF treatment, you might have a stuck lifter.. if thats the problem you might not get to see the inside of your engine.

If not pull the valve cover, this sounds like removing 4 bolts on a small block and just lifting off the cover doesnt it?

go ahead and drop by your local dealer and get some new nylon rocker guides and put the stamped rocker sets off your old engine in there.

BTW take some time and check for broken valve springs!!

Lotsa luck with the stuck lifter theory. You may have got a chunk of sludge loose while changing the engines.

[DmaxMaverick]

Before you pull the valve cover, confirm the noise isn't an injector. Worn injectors will make a noise very similar to valve noise. They're easy to check. With the engine running, loosen the injector line nut at the injector. If it is bad, the knock will stop. Pull that injector and switch it with one from the other side. If the noise follows the injector, then that is the problem. If the noise remains at the same hole, it is a valve train problem. Pulling valve covers is no picnic, and I suggest you avoid it if unnecessary. Valve train parts do fail, but more often than not, it will be a fuel issue causing a knock.

[Slim shady]

That '82 will have cast rocker arms - pull the 'cover, bring each cylinder to TDC, wiggle the rocker on each valve at TDC, see which one(s) is looser than the others - pull the shaft(s), look for grooved shaft(s) and rocker(s) on the bottom side at the fulcrum pivot points


This is sound advice, a very common problem and easily rectified. You will have to pull the intake and injector lines but not the Injector pump. This is not a hard job just a little more involved than a lot of people are comfortable with or want to do.