Mojave Heater problem

Well, I installed a Flex-a-lite Mojave heater in the CJ5 before we moved back to Kentucky, and everything seems to work great - except - the blower fan makes a weird grinding noise. It almost sounds like something actually is hitting the fan. It'll blow for a second, and then bog down and sound like it's chewing something up, and then blow fine again for a few seconds. Even when it does make the grinding sound, air continues to flow. Has anyone taken one of these heaters apart to repair it? I hate to mess up a brand new heater - and it works - but that rattle/grind/food processor sound is killing me. Tips, hints, ideas?

Much appreciated!

 

Turn up the radio.

Seriously, take it apart, something let loose and is gonna bind it up or break it eventually.

 

Bearings or brushes.

 

Or something got down inside. Take it apart and check it out.

 

I had one that mice made a nest in. Made a horrible noise.

 

I don't know anything about those heaters or where or how they are mounted. On my factory set up, some how leaves get down in there, I think through the vent up on the cowl. Ive had to take my heater apart before for the same reason and found a couple of leaves in there that the fan was hitting. Kinda sounded like the baseball card in the tire spokes of your bicyle. It would make the noise sometimes and sometimes it wouldn't.

 

If it sounds like something is interfering with the fan there very well could be. I’d open it up and see what’s going on.
When I first bought my Jeep it had a mud daubers nest in the fan squirrel cage but it had the fan so locked up it was blowing fuses. Funny what you’ll find in the fan.

 

The fan blade could be slipping on the motor shaft.
Andrew

 

I took everyone's advice and took it out. That thing is a booger to deal with. Turns out, the fan came from the factory too far on the shaft - which meant it was hitting the case of the heater. Slid it towards the motor a little bit and it works great. Ah, the simple things. Andrew was right on! Then had to go back and burp the whole cooling system. Fun. But crisis averted! Thanks for everyone's input!