Lifters tapping away. Comes and goes at idle. Goes away at spool up. Got worse with oil change to 20w50. Reco's to quiet them down? Lucas additive? Switch to 10w30 synth? Live with it?

164k on the mill. Heads and pistons already reworked. Just replace the timing belt and front seal.

New truck to me but have complete maint. history and parts replacement records.

I think the choice of 20W-50 was a mistake for a number of reasons. I would not try additives.
I had much the same problem for quite a while. I finally tried synthetic Mobil1 0W-40. Not had a lash adjuster problem since, even in cold weather (North Carolina). At the time I put the Mobil1 in I had 123K on engine with original heads and bottom end. I only put about 5K to 6K on this truck a year so I'm doing once a year oil changes with a new filter and top up at six months. This helps offset the cost of synthetic. I'm not advocating Mobil1 as probably any 0W-40 grade would work. But for me Mobil1 is easy to get and about $4 per quart which is about half of what a cafe' oil would cost. I use Redline on my 03 Ford Ranger and Castrol non-synthetic 10W-30 on my 95 Camry. You may also want to change the oil at 1000K with the switch to flush out all of the 20W-50.

I am not saying you are wrong and I am right. Before I swithed out a couple dead lifters, 20-50 really helped with my lifter tap. Made it real quiet.

One day I took out all of my lifters and compressed them by hand. 2 of them were really sloppy and very easy to compress. They were a lot different than the others. I went to Auto Zone, they actually had 3 in stock. I bought 2 at $12 each. I soaked them in oil and compressed them while in the oil to fill them up. Fixed it. That was a ton of miles and a few years ago. Still pretty quiet, I have an exhaust leak now that would over power the sound of the lifters if they are tapping. <img src="/forums/images/graemlins/smile.gif" alt="" />

Sparkem, I think there are two different problems here. One may be that worn lash adjusters (LA) won't hold pressure and so 20W-50 reduces the leakage. The other is that the LA's drain down overnight and take a little time for the oil to pressurize them. My problem seems to have been the latter so using a 0W grade allows the oil pressure to build faster on startup. I don't like using 20W-50 on street vehicles as I think it takes far too long to circulate on a cold engine and I think it is overkill.

Ok I see now. <img src="/forums/images/graemlins/kewl.gif" alt="" />



Exactly

Ill be switching out the 20w50 petro oil to 10w30 amsoil syn. and a new filter. I use amsoil in all my other vehicles including cycles, except the 1971 landrover. I run 10w30 petro in that one.

Thanks for the ideas. Im thinking my lifters are leaking down at night. But then again once they quiet at speed they will get noisy again at idle after a bit if idling.

12.00 each at autozone sounds reasonable

$12 each was a couple years ago. If they quiet up after driving, it is probably not broken or worn out lifters. My noise was constant, never went away until fixed. I would try different oil first before you start replacing lifters. Is it real bad, or can you live with it?

I can live with it for sure. I think the syn. oil will really help. Its made it to 167k so it ought to make it further....

Sometimes light piston slap sounds like a bad lifter tick. Thick, cold 20w50 will quiet light piston slap for a while, and piston swell when hot might make it quieter when warmed up.

I keep wondering where the air gets in. Is the siphon past the pump gears enough to suck air into the main/rod/cam bearing clearances? Or just the cam bearing clearance, near the lifter?

Even without an antidrainback valve in the filter, with a good film strength oil, I'd think that the oil system would stay primed, unless there is a real fat oil clearance somewhere, or I'm missing another source. Weak check ball spring in the HLA? Inside the little pin hole on top of the rocker? Anybody?

Last winter I went to Canada and found that on really cold days on cold engine startup AND in AWD, the AWD chatters like piston slap or lifter noise. At first I didn't know what it was and thought it was just the lifters as it occurred when on accel, backing off pedal made it go away. I then took it out of AWD to 2WD and the noise went away. On warm engine no noise. Putting LS additive in the transfer case quiets it down. Any thoughts on why this happens as well?