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Brown Sludge on Coolant Dipstick?

Buz

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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?
 
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?
My truck doesn't have a coolant dipstick, so I can't answer that question. But you should get your system flushed - it's not good to mix coolants like that. Here's what the owners manual says:

1674221289219.png
 
My truck doesn't have a coolant dipstick, so I can't answer that question. But you should get your system flushed - it's not good to mix coolants like that. Here's what the owners manual says:

View attachment 149326
Thank you. I was afraid of that. Pretty sure I dumped a bit of 'standard' coolant in there last year just to top it off.
They really should have a something clearly marked on the cap of the coolant reservoir warning of that.
I'm going to bite the bullet and take it in for a flush. Not something I want to do myself since it's a pressurized system.
 
Thank you. I was afraid of that. Pretty sure I dumped a bit of 'standard' coolant in there last year just to top it off.
They really should have a something clearly marked on the cap of the coolant reservoir warning of that.
I'm going to bite the bullet and take it in for a flush. Not something I want to do myself since it's a pressurized system.
it is in owners manual page 393
 
I’m sure it has a dipstick it sits flush under that cap.. I had th same issue, dealership said it wasn’t a warranty issue and had to flush it myself..
 
Thank you. I was afraid of that. Pretty sure I dumped a bit of 'standard' coolant in there last year just to top it off.
They really should have a something clearly marked on the cap of the coolant reservoir warning of that.
I'm going to bite the bullet and take it in for a flush. Not something I want to do myself since it's a pressurized system.
Another concern is why did you need to "top off the coolant"? Are you losing coolant?
 
Thank you. I was afraid of that. Pretty sure I dumped a bit of 'standard' coolant in there last year just to top it off.
They really should have a something clearly marked on the cap of the coolant reservoir warning of that.
I'm going to bite the bullet and take it in for a flush. Not something I want to do myself since it's a pressurized system.
I don't think there are any modern vehicles that come from the factory with regular green antifreeze anymore. Dodge/Ram/Chrysler hasn't used it since the introductin of the Hemi in 2005. If you completely drained and flush the system you can refill with it.
 
I just checked mine and the fluid is clean, without any brown sludge. I didn't know the tank had an 18" long dipstick.

20230121_085831.jpg20230121_085917.jpg
 
Another concern is why did you need to "top off the coolant"? Are you losing coolant?
Because I like to keep my overflow resivior filled to max. The level was probably in between when I checked, which I’m sure ram does from the factory.
Anyway I’m fully prepared to pay for the flush. At this point I’m just hoping this thread prevents others from doing it.
 
My truck came with the reservoir empty. I tried to find a compatible alternative to the mopar coolant, but was skeptical of any I could find locally.

I ended up ordering the OEM stuff.

17ce592f4a8980df30b0d380ff2cdc03.jpg
 
I have 94k on my 2020 Ram 1500. I have never added any coolant and it has that brown sludge. I just checked first time tonight. Never have had any cooking issues and it’s been upwards 100F temps.
 
I have 94k on my 2020 Ram 1500. I have never added any coolant and it has that brown sludge. I just checked first time tonight. Never have had any cooking issues and it’s been upwards 100F temps.
I actually just did the same thing. I have 48k on my 2020 ram. Noticed the wife's van was a little low on coolant and thought I'd check my truck. Dip stick had the brown sludge and per the dip stick the overflow tank was virtually empty. I've personally never added any coolant. Led me to doing some research and ordering the appropriate coolant. I continued to drive on it though because temps never got over 205.
 
I've been checking the coolant dip stick maybe every two months. Levels have been good and no sludge that I can recall.

Anyone have a pic of the sludge?
 
Because I like to keep my overflow resivior filled to max. The level was probably in between when I checked, which I’m sure ram does from the factory.
Anyway I’m fully prepared to pay for the flush. At this point I’m just hoping this thread prevents others from doing it.
There's no benefit to keeping the reservoir full to the max. It won't hurt anything but you're wasting coolant if you fill it when the engine is cool. As the engine warms up the coolant expands into the overflow reservoir, which is why it's there. If the reservoir is full when that expansion happens there's nowhere for it to go but out of the reservoir vent and onto the ground. Have you ever smelled coolant after driving your truck?
 
There's no benefit to keeping the reservoir full to the max. It won't hurt anything but you're wasting coolant if you fill it when the engine is cool. As the engine warms up the coolant expands into the overflow reservoir, which is why it's there. If the reservoir is full when that expansion happens there's nowhere for it to go but out of the reservoir vent and onto the ground. Have you ever smelled coolant after driving your truck?
I'd be surprised if you talk to a Ram owner that hasn't smelled coolant after driving truck at least once.
 
I'd be surprised if you talk to a Ram owner that hasn't smelled coolant after driving truck at least once.
I get it, you're being funny. We've owned 8 Ram trucks over the last 14 years and I don't ever remember smelling coolant after driving any of them. Our '06 Nissan Pathfinder on the other hand, don't get me started LOL.
 
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I get it, you're being funny. We've owned 8 Ram trucks over the last 14 years and I don't ever remember smelling coolant after driving any of them. Our '06 Nissan Pathfinder on the other hand, don't get me started LOL.
I've smelt it with my truck many times. Maybe I notice it more parking in the garage. Noticed it more when it was newer. 34k miles, and reservoir is still in "safe" zone on dipstick, but could use a little.
 

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