I'm down to one working car, my 300D, right now and getting nervous because I've twice noticed a rather nasty scraping sound coming from the power steering pump (I think) when I turn the wheel left at idle or close to idle. Have never heard it while turning it right. I just noticed it when I pulled into work to park, but now it's gone. I do hear, any time I hear the wheel, a very light scraping sound coming from the pump, but nothing I would have noticed if I weren't listening very carefully. The intermittent scraping is pretty noticeable, though. No squealing or whining (yet). Steers easily in either direction.
From searches it seems the sound is coming from the pulley or bearing in the pump and there's not much I can do other than replace it. Fluid is at the fill mark and fairly fresh ... I changed the hoses and did a flush less than a year ago (with MB fluid). What I did NOT do was change the filter, because I can't get the nut off the post that holds it down. 1) Could the filter be the problem? 2) Any advice on getting the nut off? It just spins, even if I push up on it while spinning it ... I think because I overtightened it the first time I changed the filter several years ago (lesson learned).
And I guess the big question: How worried should I be? I'm supposed to be at a wedding 600ish miles away Saturday, and my Jeep won't be ready by then. Can't afford to fly or rent a car, but maybe could borrow one. Should I hesitate to take the 300D on that long a trip? If the P/S pump is taking a dive, how suddenly is it likely to go downhill?
I will doublecheck the origin of the sound with a stethoscope when I can.

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1987 300D, arctic white/palomino--314,000 miles
1978 240D 4-speed, Euro Delivery, light ivory/bamboo--370,000 miles
2005 Jeep Liberty CRD Limited, light khaki/slate--140,000 miles
2018 Chevy Cruze diesel, 6-speed manual, satin steel metallic/kalahari--19,000 miles
1982 Peugeot 505 diesel, 4-speed manual, blue/blue, 130,000 miles
1995 S320, black/parchment--34,000 miles (Dad's car)

when you turn the wheel, the PS pump is loaded, it's possible you have a weak or worn belt. you could also have a weak spring, a worn tensioner or pulley, or both... many things make noise under load...

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

OK, thanks ... I was wondering that, if the P/S load could also cause noise from somewhere else. I have a new tensioner, pulley, spring in a bag that I was planning on installing along with a new belt at some point because I thought they might be responsible for some minor vibrations I had. The belt looks fine on inspection but is fairly old and seems like a good idea to replace if I replace all the other stuff. The vibration stopped over the summer so I kind of forgot. I will have someone turn the wheel while I listen in the engine compartment to narrow down the issue.

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1987 300D, arctic white/palomino--314,000 miles
1978 240D 4-speed, Euro Delivery, light ivory/bamboo--370,000 miles
2005 Jeep Liberty CRD Limited, light khaki/slate--140,000 miles
2018 Chevy Cruze diesel, 6-speed manual, satin steel metallic/kalahari--19,000 miles
1982 Peugeot 505 diesel, 4-speed manual, blue/blue, 130,000 miles
1995 S320, black/parchment--34,000 miles (Dad's car)