3.9 efi fecking horrendous screeching, thoughts?

so its a 3.9 disco 1 MY94/5

the wife returned from work friday and promptly stuck it in the garage and told me it was making a weird noise, so come sunday morning, and the only free time I had as Im currently working saturdays and had a party to attend to on saturday night, i went down to the garage and fired it up and she is right, its grinding itself to death on something in there.

I pulled the starter out and checked it wasnt the bendix not retracting (doesnt seem to be a problem fired the starter and it shot out spun and when powered down shot back in), checked oil and autobox levels both fine.

it doesnt seem to be causing much if any drag on the engine but it is bleeding awful sounding, anybody got any ideas?

It is engine speed dependent, i.e it increases pace with the engine. sounds painful and when i stuck the stethoscope on various bits it does seem to be loudest on the starter body/bellhousing. so to reiterate it is a grinding sound with a definite screech to it. louder at idle but then thats probably because you cant hear much once the thing is revved with the straight through.

come on chaps help a brother out here.

Does it always make the noise regardless of wether it's in gear or not? Could it be the spigot bearing? There's not a lot else at the back of the engine that could make that sort of noise.

My gut says water pump. Not sure on a 94/5 engine if you will have the full serp belt but if not try popping the fan belt(s) off and then fire it up. You could do similar to rule out power steering pump, A/C compressor (if fitted) and the alternator. Also check belt tensioner bearings. If it isn't any of the ancillaries then you might have to dig deep inside. HTH

Yep, as Kev says, check the tensioner bearings. In the absence of a replacement, unbolt and remove, clean it up, apply Wynns engine lubricant/WD40 + grease packed in and REVERSE the wheel when bolting it back on. Worked for me. Went from a dreadful howl to silence. Obviously replace it in the long term.