I have a 96 disco 1 with 155k. It runs well, after the usual minor to medium cost repair about every month, except the new issue: a sound EXACTLY like a cricket chirp coming from (my best guess sticking my ear into the hood) the rear passenger side top or bottom of engine. It gets more intense in speed and volume the more throttle (regardless of speed) under load. If i am going 60 and let off the gas, the noise stops. It is loudest when accelerating and at a stop or coasting the noise disappears completely. It has nothing to do with any belt, tensioner, pulley or pulley bearing as those are all new from an earlier problem. I have seen a lot of people with this problem say it was the cmp or camshaft position sensor o ring and replacing this fixed theirs. I just put a brand new one on mine and excitedly put all my tools away to drive it and the SAME SOUND IS STILL THERE! The truck drives 100 percent fine, full power and everything just this loud embarrassing noise! what other part can this be?! i am stumped and would be eternally grateful for some input

 

So it does no matter what, engine cold, warm, doesn't matter it makes the noise.

Have you tightened the exhaust manifold bolts?
Have you checked your catalytic converters to see if they are still good and not falling apart on the inside?
Are your plug wires any good? If one is arcing it can sound like a tick.

 

drain oil to remove crickets.

No really im not sure, if its coming from inside the engine you better get used to it. What is the interval between squeeks? Does it happen with every cylinder fire, every other one or 1 out of every 8.

check muffler studs and engine mount

 

yes cold warm, and its not coming from an area as far back as the cats. i will check the manifold to catconverter gasket area to b safe thx.i will update you when i find out how tight they are

 

mounts are good, and the squeak is every fire, as fast as an uzi when i step on it and slower the less load i give it.

 

and its not a tick its identical to a cricket chirp, a high pitched chirp

 

I switched to the Max Life oil and mine got lots quiter and smoother.

 

sounds like an exhaust leak. Have you noticed any smoke coming out of the exhaust manifold where it meets the exhaust? When I did my induction cleaning I saw that I have to change the exhaust gasket there.

 

Those gaskets do tend to burn thru in the middle over time.

Crickets are supposed to be good luck, you may to leave them in there.