My 2001 E150 has a knocking sound coming from the flywheel area, which corresponds with the engine speed. I can hear it the most when I'm backing out of my garage and the sound bounces off the block walls. At highway speed I can't hear it all all. I should mention that I have been driving it like this for over 5 years and 50k miles, and the sound hasn't changed.I bought the van used with 23k miles, and now its around 72k., and the noise has always been there.

Its been up on a lift to check the sound with a scope and its definitely at the flywheel.

I don't drive the van much any more, but I am ready to finally get it fixed. So what could it be.... flywheel, starter? Is there a way to know without taking it all apart?

Please let me know what you think.

 

out of balance

 

original starter. ever had this problem before?

 

Its probably the original starter, since I got the van with 23k miles on in, and I haven't put in a new one. This knocking sound has always been there, and I hear it mostly at low rpms, in any gear. The engine and tranny both run smooth. A local shop told me that the starter may need to be shimmed,or possibly the flywheel is cracked, but I wanted to see if forum members had other ideas about it.