FE350 slight knock under load when warm

[dieselwulf]

Well, after doing the head gasket my smoke issue cleared up, but now that the engine runs properly I have a slight knock under load and accelerating, its a very strady rhythmic knock and its pretty dull sounding and not affecting performance. Put about 7 hours on the cart over the weekend with no issue and the noise did not change. I'm just unfarmiliar with how these engines run, are they normally quiet or do some have a slight knock. When I got it, the crankcase had more gas in it then oil, so I am presuming at some point it was run lime that, for how long I don't know. I see the crankshaft has no bushings or bearings, so I'm suspecting it may be going bad. But I see this engine also has a balancer assembly with its own crankshaft. Any insight would be appreciated. Thanks!

[Fairtax4me]

It may make a little noise, but the thing to watch out for is when you change the oil look for silver in the oil.
The 350s have aluminum link rods for the counter balance weight and the rods are prone to wear. They make a ton of noise like you're riding around with an air hammer in the engine before they fail completely, but if you run it to failure it will break the rod.

[dieselwulf]

Now that you mention it, the oil was shiney with silver flakes in it when I first drained the crankcase while it was filled with oily gas. I guess I should expect the worst.

[Fairtax4me]

Damage is already pretty much done. The rods chew up the crankshaft quick and the crankshaft is about $800 by itself. Plan on putting a new or rebuilt engine in it.