P0171, P0174, and P0734.

 

0171 and 0174 are the O2 sensors running Lean. 0734 is an o2 sensor code as well. check a few things, what size and brand spark plug wires do you have? what about the air filter when was it last changed? the codes make me believe the MAF sensor is on its way out or needs to be cleaned. also check for air leaks and that all the clamps are tight. that is a start to your troubles. as for that video and the sound you hear i don't think its related to the codes. are you losing coolant? check the serpentine belt for any cracks of odd wear.

 

I think I found the air leak, and reset the codes. So far, so good. It is not leaking coolant, as far as I know. As for the spark plug wire, they were on the vehicle when I bought it; not sure of the brand. The serpentine belt looks OK as far as I can see. I tightened a few loose bolts on the engine and some of the clicking sounds are reduced. I think the other sounds from the front of the engine are a bad pump or pulley. Any input would be helpful. You guys have been awesome so far. Thanks!

 

check out disco mikes 60k service thread in the "how to" section of the disco section. it tells you how to change all your fluids, get a pair of descent 8mm wires and some platinum plugs and get that truck runnin like new again.

 

Changed the plugs tonight, Ordered the Magnecor 8mm wires, Doing the engine flush tomorrow, Royal Purple oil waiting with Mobil 1 M1-301 filter.

 

Engine flush completed, RP 15W-40 oil added. Still hearing the noise. Open to any suggestions. The clicking is mostly gone, but the louder noise is there.

 

I have a 99 D2 that does both the things you described. For me the vibration was caused from the fan having a broken fin causing it to be out of balance. Because the fan has a clutch it took a while to figure out, goes away when you give it gas etc.
My tension pulley also made that loud winy noise.