We have 2 88 Camry Vzv21's V6 2.5 litre jobs 2vz-fe engines to be precise. They both run, the first has a knock in the motor, the other has had fully reco cylinder heads and done only 30kms when it developed the very same Knocking sound. WTF? Is there a common fault with these engines that fails that anyone knows or has heard of? Seems too much of a coincidence to us. The newer engine has not overheated nor run out of oil. Any ideas? Thanks. RJ.

Youtube both of your cars and post the video here. Is the knocking more like a slap? You sure it's in the top of the engine and not coming from the block?

Hi ,
Umm more like a loud clack clack clack sound...get faster / louder with revs, but quietens some on idle...We liken it too the loose rocker post noise. We believe its top end doesnt sound deep enough to the crankshaft area.

My guesses would be weak or broken valve spring, worn shims, or worn or sticking valve guides. Run a regular compression test to see which cylinder(s) is the culprit.

Hard to understand how two engines can have the same symptoms, which are unusual for that engine to begin with. I would worry about sabotage from someone who has access to both cars.

However, taking off the head cover and checking valve clearances may turn up the culprit.

Will be doing some serious looking soon and will let you know what we find. If for no other reason than to advise anyone with a similar noise/ issue with these 2 vz engines. :wink: