I am hoping someone here can help. I have a 86 nissian kingcab 4X4 with a z24 engine w/ 154k on engine. I have a horrible whining noise that is getting worse and worse in/on the engine. It sounds like a mosquito buzzing around when I give it gas but a 100x's louder. At first (about 4 months ago) it would only do it for a while when I started it up but it is doing it all the time now. It runs great, good gas milage, etc. It is just that noise. Does anybody have any suggestions on what I start looking for? Could it be vacume or catilitic converter? If anybody knows please reply it is driving me crazy!

Thanks, Krocus

Try this forum:

www.4x4parts.com

Need more info to help you locate the trouble.
IE

Automatic or Standard?
Do you hear the noise at idle?
Does the noise go away when you take your foot of the gas and just coast?.
Does the brake pedal feel like it pulsates when you push it?
Does the noise go-away when you brake hard? Gentle?
Do you hear it when the truck is moving or all the time, sitting still and gets worse as you drive? <img src="/forums/images/graemlins/confused.gif" alt="" />

The noise is something that I have never heard myself, but
I owned an 85-720 and a 95 Hardbody. With the noises these 2 trucks made I might be able to help you locate the trouble.

It's probably the AIV filter box went bad they tend to rust right through.