1992 Nissan Pickup KA24E: Strange new whistling noise.

[D21_Destroyer]

I have a 1992 D21 pickup with KA24E engine and 5 speed manual RWD. It recently started making a whitsling/whining noise at about 4500 RPMs. The noise goes away if you rev higher or lower. I'm not sure what's cuasing this or if it's cause for concern.

The only recent work i've done is to put in some nology hotwires when my old wires literally snapped in half, and an oil change. I've been having problems with a lifter somewhere that has been causing a ticking, but i don't think the two are related as the lifter has been messed up for a while without causing a problem.

Side Note: If anyone knows of a good way to clean the hydraulic lifters that's my next project. i'm hoping that stops the ticking which doesn't seem to be a major problem but probabyl won't be good in the long run. if there's no good way to clean them, how would i check for which one is messed up, because i can't afford to replace all 12.

[blackd21vg30de]

hey my 93 ka hardbody did this bout 4 years ago and about a month after it started my water pump went out, replaced and never heard it again.. hope this helped!!

[jmd]

Pour about 1/2 a quart of automatic transmission fluid in with the oil. It will clean the inside of the engine and lifters.

[Desert Rat]

Engine or exhaust? My '98 did this until I replaced the exhaust system with something less restrictive. It could be a partially plugged cat.