For the last 10,000 or so miles, my alternator has been sounding like a coffee grinder, and it's been getting worse. It works fine, just makes a bunch of noise. I am guessing the bearings are going bad.. time for a replacement or will it keep going?

My water pump appears to work fine also, no noise, no leaks but It hasn't been changed in 95,000 miles. I do alot of highway driving and I really don't want to get stranded in the middle of nowhere. I am starting to worry about it failing. I had one fail on a 300SD, worked fine one minute, was gushing hot coolant the next, is that the typical failure, or will it slowly drip? It's really not alot of work and not alot of money, but the question is do I need to do it?

That's all for now. Thanks.

Before you swap out the alternator remove the belt and spin it to insure that is where the noise is coming from. If it is I would go ahead and change it. The water pumps I have seen go bad started dripping which provided plenty of warning.

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Jim

The water pump on my SDL was dripping for ten+ years. I wasnt using it much, so I didn't worry about it. Now that I am using it daily, I got it replaced when I had to get the fan clutch replaced. An independent shop did a great job on it. Good luck.

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Paul 1987 300 SDL; 2000 ML; '69 MGB; '68 VW Fastback

I changed out mine when it started weeping from of all places- the weep hole!!. I think it cost $25.00 or so from the dealer. Easiest water pump I've ever changed in my life. Can't beat a mid 80's MBZ Diesel!

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Orland Park, IL
1985 300SD 215,000 miles

When I replaced my water pump, it was making a similar noise, but when we had it apart, it was actually the bearing in the belt pully that was making all the racket.

Just my $.02.

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Paul S.

2001 E430, Bourdeaux Red, Oyster interior.
79,200 miles.

1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".

Replace them both, its worth the peace of mind

Amen. They're really not that expensive, but it's hard to put a value on piece of mind anyway...

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Paul S.

2001 E430, Bourdeaux Red, Oyster interior.
79,200 miles.

1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".

TD:

When you go to replace the alt, do so with a few hours to spare. What appeared like a simple job was a pain. Perhaps I just did it wrong, but a couple of other guys agreed.

Then again, perhaps the SD is different from the D

Don

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DAILY DRIVERS:
'84 300DT 298k (Aubrey's)
'99.5 Jetta TDI IV 251k (Julie's)
'97 Jetta TDI 127k (Amber's)
'97 Jetta TDI 186k (Matt's)
'96 Passat TDI 237k (Don's
'84 300D 211k Mint (Arne- Undergoing Greasecar Conversion)

SOLD:
'82 240D 229k (Matt's - Converted-300DT w/ 4 speed

I just upgraded my stock 70A alternator (same as your SDL) to an M119 143A unit. My old one was working fine, I just need higher output for my stereo. If you want to buy a good used one, I'd be happy to sell mine pretty cheap, it's taking up space in my garage...!

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Dave
Boise, ID
Check out my website photos, documents, and movies!

My evans no pressure coolant makes the waterpump last much longer. That alone may pay for the added cost of the coolant.

P E H