Overheating and lifters
Eventually it did go away, as the lifters regained their oil through regular driving. Assuming yours were not damged from the over heating, they should quiet down. Might take a while.
Last edited by johnnybravo; Oct 20, 2010 at 04:06 AM. Reason: spelling
I've put cams in from some manufacturers that want you to install and do the initial start up on empty lifters. They only make noise for a few minutes.
they will fill with oil instantly as soon as oil pressure hits them,
and they normally drain (bleed down) when the engine is off so to say they drain when any time head work is done is wrong.
what engine is this on and more importantly what type of rockers are in the heads?
If they are adjustable rockers then the lifter preload was probably set wrong and the noise you are hearing are the rockers clattering because of insufficient lifter preload.
If they are non-adjustable rockers then lifters just get tightened down completely and the lifter preload is determined primarily by the pushrod length. normally it's the rockers that make the noise, not lifters. If it is a lifter that is damaged, it would be from oil coking inside it from the overheat condition and the lifter is clogged, so it can't fill properly with oil and take up the slack between the pushrod and rocker, and it also probably isn't flowing oil up the pushrod to the head. the fix for that would be either replacing the lifters, or pulling each one apart to inspect and clean which isn't hard but time consuming. The shop should have checked lifter preload or looked for valve lash when reinstalling the head and tightening the rockers, if checked properly and there was none then look at the lifters. if it's not that, then start looking for bearing damage from the overheat condition and the oil getting too hot and not having enough viscosity, especially if a 5w30 oil, because it's a bearing knock you are hearing. since you overheated and blew the head gasket, the engine had to get pretty hot.





