since it's almost summer and i plan on making some trips over the pass with my little boat, i switched my oil to 15w40 in my 22R-E. i'm not sure if i just haven't heard this noise before and i'm now noticing it with my window down, or what, but i can hear that distinct timing chain rattle.

i replaced the whole shebang back in september after i bought the truck with EB's parts, and it always seemed to work fine. i've always ran 10w40 in these engines with good success, but i noticed that in the '93 FSM it says run 10w30 everywhere, and 5w30 in cold climates?

the engine runs fine and doesn't make any other wierd noises...just that ominous timing chain slap. is 15w40 too thick for the PNW and it's not able to pump up the tensioner like it should?

I usually run either 15W40 or 20W50 in mine year-round. Seems to work well for me. Anything lighter than W40 and my hot idle oil pressure drops very low on the factory gauge.

I have always ran 10-30 year round in all of mine, '82-'91, without any problem.

Drain the 15-40 and run 10-30 and see if the noise goes away.

by anychance could you get a little video of this sound your hearing? Im wondering if im experiencing the same problem you are. After my mechanic changed my oil/filter I began to hear this odd noise as well in my 22RE

I just went from M1 5W40 to M1 0W40. Works great. When I had 5W-40 in I added some older M1 15W50 I had sitting around (toward the end of the oil change period; I had no 5W-40 on hand). It was only about a 1/2 quart, but the truck seemed just fine with that overall more viscous mix.