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Valve train noise

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pismo10

Contributing Member
I have a well running 273 with hydraulic lifters, rocker shaft assembly with stamped non-adjustable rockers. So the push rods should be fairly tight against the rockers when unloaded, just able to spin them when cold. I found a couple were looser than this therefore making some ticking noise while running. So I re-torqued the rocker assembly shaft bolts, which tightened things up and helped reduce the noise greatly. Lube is flowing well to all.

I am new to these engines and was wondering what tends to wear to cause this looseness and subsequent noise? Is it the rockers that tend to wear or the lifters or push rods?

Any experience would be helpful.

Thanks very much
 
The lifters on mine clanck a bit on cold start up, then quiet down from then on. If yours don't quiet down, your oil needs more frequent changing (and/ or your PCV system isn't working correctly).

Jeff
 
More research finds that most commonly it is the tappets that are not pressuring up fully. After checking the rockers and push rods (which is fairly easy) the tappets are next. A good cleaning or replace, fresh oil, etc.
 
Thanks, I think I agree. Where can I get the magnetic? tool to pull the lifters up out through the heads without removing the intake? Thanks.
 
Don't waste your time trying to do it that way. Those things will have build up around the bottom of the lifter that will defy removal, and even after gripping and tugging on them with Vise Grips. Not hard to pull the intake on these motors--the distributor doesn't even have to come out.

Jeff
 
An oil change and a nice big K&N filter has made a great improvement already. Better pressure. I don't hear anything anymore. I bought the boat 3 weeks ago and have no idea when the last guy changed the oil..Seems to have helped.
 
The best way to remove stuck lifters is to fill an old squeeze type oil can with lacquer thinner and drip it down the side of the lifter as you pull it up with your fingers or pliers...the results are amazing. Don't forget to change the oil to remove any contamination. Kd tools makes a lifter remover tool but unless you use the lacquer thinner, it doesn't work very well. To prevent carbon build up on any engine, change the oil frequently and only when the Engine is at maximum operating. Changing the oil on a "cold" engine leaves much or the dirty oil behind.
 
Just take it really easy on the motor 'til it warms up and the racket will go away again. One of mine pounded like crazy this Spring. Quiet now.


Jeff

PS: Please don't tell me you didn't change the oil at the end of the season!
 
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