Brown Sludge on Coolant Dipstick?

[Mikaelisu69]

Pulled my coolant dipstick out yesterday and noticed a brown sludge on the lower part of the stick. (5.7 hemi) Almost like a dark applesauce consistency.
Engine has only 16k miles.
I may have topped off the tank last year, honestly can't remember, with a standard Prestone coolant. Thinking this could be the cause?
Coolant temp runs normal at about 201 degrees.
Does anyone else have this brown sludge on their coolant dipstick, or did I cause this by topping off with a non-OEM coolant?

Just checked mine and it was completely empty with brown sludge on the dipstick. Only have 31,000 miles and had the engine replaced at 11,000 miles because it was using 1 at of oil every 1000 miles. Been to the dealer multiple times and assumed they were checking fluids but I guess not.

 

[HSKR R/T]

Fwiw my truck, with 75k miles has a completely clean coolant dipstick. I have had to top off my reservoir once because it was low enough dipstick was dry.

I also still get the coolant smell on hot shut down from time to time.

 

[Bigdumps]

Fwiw my truck, with 75k miles has a completely clean coolant dipstick. I have had to top off my reservoir once because it was low enough dipstick was dry.

I also still get the coolant smell on hot shut down from time to time.

Friends who rode in my truck said the same about mine, always said they smell coolant. Turns out my heater core was shot, then discovered my rad had a crack in it.

 

[HSKR R/T]

Friends who rode in my truck said the same about mine, always said they smell coolant. Turns out my heater core was shot, then discovered my rad had a crack in it.

You would be losing coolant if one or both were bad.

 

[KrustyKush]

This happened to me only two weeks ago. 2021 Laramie 5.7 non eTorque. While planning a 3k mile trip, I checked coolant level. Engine bone cold, sat overnight. I found the dipstick dry, with brown sludge gathered in the little holes on the dipstick, and along the sides. Before pulling the radiator cap, I ran down to nearby RAM dealer and bought a gallon of pre-mix Ram OAT coolant, and a new radiator cap. Back home, pulled the cap and found the coolant level up in the spout area, so not terribly low yet. The coolant had a brownish, opaque look to it.

I cleaned the spout area real good. I added enough coolant into the radiator to bring level up to the top of the spout. Then, installed the new radiator cap. Then, brought the level in the expansion tank up to mid-way between upper and lower, and went for a ride.

All was well. Completed the 3k trip without a problem, checking coolant level several times along the way. I must have ignored my coolant level for far too long. I won't do that ever again! Now thinking of taking her in for a system flush, even though only have 40k miles on it.