Ending the saga, with a warning.

I purchased the M4 auxiliary fan that was in my car from an ebay seller, "rojoimparts." This fan assembly appears to have failed after less than a year. It runs when full power is applied, but it's not the howl that the OEM fan gives. Since I wrote the above missive, the weather has turned warmer and made me realize that something was very wrong. When coming off the highway to a stop, I realize that things warm up, but this fan was not enough to prevent the engine temperature from steadily climbing, even with the fan at full power.

So the warning, of course, is don't buy this fan assembly. In fact, I'm completely done buying any MB parts from ebay sellers.

It was a twin-motor design, apparantly like the ACM fan that Phil sells, but I very much doubt that it is the same part. For one, there are no identifying marks on this assembly. It did cost about the same as the ACM assembly that Phil carries, but it is apparantly of very low quality.

I got a new OEM fan motor (which is the left side only) from Phil. Good price on the part at about $205. There was apparantly a small mixup in the shipping, so he sent one next-day air last week. I very much appreciated that, since I could install it in my old OEM fan assembly over the weekend.

The new fan howls at full speed, and you can feel a lot of air coming through the radiator with the engine off. It does a lot better job at controlling the engine temperature with the AC running.