03 4.7L Valvetrain noise

[greener]

I've started to hear a clickling noice coming from somewhere in the valvetrain area of the engine. I'm guessing it's the lifters making some noise, it only seems to do it for the first 10-20 seconds after you start the engine. Oil gets changed every 3-5k w/ Mobil 5000k 5w-30. Engine has approx. 95k miles

Any ideas?? Also looking for the stock spark plug # denso or NGK???

Thanks

[Burger Steak & Eggs]

It might also be a leak in the exhaust manifold.

[kathyricks]

If you do alot of short trip driving during your cold Midwestern winters then leaks can develop in the exhaust manifold that sound like valvetrain noise.

Genuine start up valvetrain noise can also be due to the use of some aftermarket oil filters, especially big oversized filters. The small, made in Thailand Toyota 90916-YZZD3 filters do a good job of retaining oil overnight and minimizing valvetrain start up noise.

Another slight possibility is that loose clearances have developed on one or more of your 32 engine valves although Toyota V8's with loose valves also tend to make a clicking noise when the engines are warm as well as cold.

[kathyricks]

Oops, I just remembered the V8 oil filter is mounted vertically, rather than horizontally, no engine oil doesn't drain out of it overnight, hence use of aftermarket oil filters should have no adverse effect on engine start up noise.