I knew it would be the alternator. Just get a napa unit. I bought a OEM one in a pinch with a friends discount and it lasted 6 months and locked up. I wasn't able to return it either so I bought the $190 napa one and it was going strong when we tore the engine down.

 

If u buy an OEM form the dealer u get a warranty. So why did u get one from napa ?

 

here you go and call it a day... and says make an offer
so offer 150 and have it put at an indy shop or my buddy adam will put it on and there you go save 500 bucks lol

http://www.ebay.com/itm/W211-W215-W2...efc6d5&vxp=mtr

 

They pulled the "we did not install it" and the regulator was actually melted and they said it must of been installed wrong (which it wasn't and couldnt be really) and would not warranty it.

 

That seems to be the incorrect alternator. For W211 in the description it only shows some E320 and an E500.

Also this one is only 150 amps, stock E55 alternator is 180 amp.



I say get the NAPA rebuild and find an independent shop to slap it in. You get a warranty from NAPA then as well. Any even kinda half assed shop should be able to handle this one.

 

this is what the link says

W211 W215 W220 W210 Mercedes Alternator Generator E430 E55 E320 S500 SL500 CL500 (Fits: E55 AMG)

soo

 

Double