Tapping sound

  • 4.2L
  • V8
  • 2WD
  • 100,000 MILES
Changed the head gaskets, lash adjusters, seals, some damaged valves and timing chain. Everything lined up timing wise when I did the manual crankshaft rotation test. However, I keep hearing a tapping sound as I rotate the crankshaft manually. It seems to be coming from the right cylinder head in the rear of the head (at the firewall). Is this normal when you install new lash adjusters? Also, some of the new lash adjusters spring down and up and others don't, is that normal? I don't want to totally put everything back together until I know if this tapping sound will eventually stop or do I need check and fix something. I soaked lash adjusters in oil for days and even took the timing chain of and reinstalled it just to be sure.
Do you
have the same problem?
Tuesday, November 23rd, 2021 AT 9:53 PM

1 Reply

Is it possible to get a recording of the noise so that we can hear what it is you are hearing and that will help confirm this?

If everything is timed properly then it should be fine, but you need to pump the lifters up before they stop making noise or even fully open the valves.

So just soaking them in oil is not going to pump them up. Most people will soak them in oil, but you should manual depress them so that they pull oil in and are prefilled so that you don't have to crank the engine and have the oil pump fill them.

It is a good idea to disable the ignition and crank the engine at least a few times so that oil is sent through the engine so that it is not a complete dry start.

Then if you start the engine and you hear a rattle then we may have a faulty lifter.


Take a look at the info attached for common lash adjuster issues on this engine.

Let us know if you can get a video of this just to be sure we are on the same page.

Was this
Wednesday, November 24th, 2021 AT 4:08 PM

Please login or register to post a reply.

Sponsored links