Fan Speed High With Normal Operating Temperatures

[jjtimberlake]

I have a 2016 RAM 3500 Cummins AS69RC with 91k miles.

I have an MM3 with a straight pipe running 30hp tune.

I have had the tuner on there for a couple of thousand miles and no issues.

During my last trip, 200 miles one way, the fan and temperatures were good. On the way home, I noticed noise under the hood like my fan was spinning fast.

All the way home, the engine and oil temp was 180 degrees, and trans was 138.

The fan spinning 850 rpm and would increase to 1500 rpm with an increase of engine rpm.

Once I got home, I found fan bracket pulley bearing bad.

While I was there, I replaced the bracket and fan clutch, thinking that the clutch was going out.

Replaced and at idle fan speed is 850 rpm and increased over 1500 rpm.

The fan speed should be under 300 rpm at idle if all temps are normal, or that's why I was usually seeing.

I also tried turning AC off and seeing if the fan would decrease speed, no change, and no error codes.

Sorry for the lengthy post, but trying to give as much information as I could.

I really appreciate any help you can provide.

*** Update I have rerun the truck; fan speeds increased, then after a couple of minutes, the speed decreased to 170 rpm and is acting normal.

I will monitor fan speeds on the next drive and see if anything changes.

Merry Christmas also.

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[18ram67]

I have an 18 that in a year with 30k miles the clutch fan went bad.

The shop I took it to said ram has somewhat of a problem with them.

The shop has an alternative to the clutch fan.

Can't remember what it would be.

Just thought I'd let ya know you're not alone.

Sent from my SM-N975U1 using Tapatalk

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[jjtimberlake]

Thanks for the reply @18ram67.

I used the dorman fan bracket pulley and a duralast (i think) for the fan clutch from autozone.

Everything's working good so far and fan speeds are back to normal.

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