Shedding Fan Blades --- Why?

[mholbrook]

When I bought my 92 535 it only had about 6 out of 11 blades on the fan. I found them all in the pan, radiator shroud and under the air cleaner. I immediately bought a new fan, installed and within a couple weeks I shed a blade.

I put another on today and went to the local indy who was concerned I might have had a bad motor mount but they are ok. He looked it over and I have an appointment in about 2 weeks to take it in for a look over the whole car prior to an upcoming trip. He didn't see anything but indicated it was probably due to a "foreign object". Said take it easy and he'd see me in a couple weeks.

Anyone else had this problem....solutions?

[SRR2]

Anyone else? Oh, yeah... http://bimmer.roadfly.com/bmw/forums/e39/7491875-2.html

Fans and clutches are going to become a PM item at 75000 miles in E39s.

[632 Regal]

id go with a new fan clutch and have them see if the water pump has any play before buttoning it back up.

[M20Turbo]

I had the same problem. After replacing the fan for the 3rd time I replaced it for good with an electric fan five years ago. I used a fan from Flex-a-lite with an adjustable thermostat and a/c relay. I thought it worked out well, less weight for the engine to turn. Plus on hot days the fan will continue to run after shutting the car off until the water cools down. I used the stock radiator shroud to mount the fan.

[tncbass]

Motor mounts might be going bad. When they wear out the engine tends to rise up inside the engine bay during acceleration which will make the blades hit the shroud. I blew apart the fan on my 540i for this reason. Do you hear a clunking sound when you get on the gas? Those motor mounts go bad around 90-100k miles.

[Andrem5]

Mike: Remove the shroud while it is still unwarm in ID and until you get around to doing all the suspension bits.

[Scott H]

hood insulation. That stuff can sag over time and maybe it's dropping in to the path of the fan. On my old 535 that area was all shredded up from the fan beating it while it sagged a bit. It was almost all gone by the time I got around to noticing it. Luckily no blade were shed.

[mholbrook]

I believe it is indeed the hood insulation getting dragged into the "open" top of the fan shroud. I've ordered a new hood pad and I'll be installing the third fan in two months. Guess I'll keep my now 10 bladed fan for dire emergency or wall ornament.

Mike