Honda Element Owners Club banner

Question: What's this gunk on my coolant reservoir?

2736 Views 12 Replies 6 Participants Last post by  bloomcounty
Hi there,

I noticed that I have this brown stuff on the outside of my coolant reservoir, under the cap, I guess? Not sure where it's from or what's causing it. See attached pictures. (I didn't remove the cap.)

Any thoughts? Anything to be concerned about?

My coolant level seems to be normal. It showed at about 1/3 above the MIN line of the distance between MIN and MAX (at morning cold temperature with engine off).

Thanks for the help!


See less See more
1 - 5 of 13 Posts
Oh, man... :-(

How do I do that? :?
Look's like old grease to me but it could be anything, hard to tell from just a pic. As to how it got there :? your guess is as good as mine, who work's on your car? anyone under your hood helping you out?
Just the dealership. For various things checked under warranty for the first three years (and Mobil-1 oil changes). (3 year warranty has passed, but I bought an extended warranty when I bought the car new.) Then the last oil change and "20K mile service" awhile back. Next oil change is still a couple thousand miles out.

I didn't notice it before now, but I don't look under the hood that often, so I might have missed it (if it was just old grease).

Should I open that plastic cap on the coolant and check for anything? Weird that it's right there, you think?

(Last time I checked the oil, the oil on the stick looked "normal" -- at least to me, which doesn't say much! I can check it again. I can also take more pics if there's anything anyone wants to see in particular to help troubleshoot?)

Yikes about the earthquake! Glad you're okay.

I went back out and unscrewed the plastic cap on the coolant reservoir and peeked in. The coolant level isn't high enough in the plastic overfill reservoir to allow me to actually see it inside, but I did not see any of the brown goop inside or under the plastic cap. (There was a tiny bit on the thread.)

And while I didn't see any white foamy stuff inside, the black plastic tubing that runs from the plastic cap down into the plastic reservoir was coated in places with "white" that wasn't easy to wipe off with a paper towel.

I didn't check in the actual radiator.

I did unscrew the oil fill cap and looked in there. No milky stuff.

I also noted that there were a couple spots of this brown goop in other surrounded locations, which leads me to think it is just old grease like marvin mentioned. There is a similar substance on the latch for the hood. And the stuff (which I did wipe off) has the consistency of grease.

What do you all think? Thanks for the help/advice!
See less See more
Thanks for all the replies! It's officially cleaned off (and I didn't need any coolant, as the reservoir was about 1/3 over the MIN line).

I'll take a look again in a couple days and see if by chance it shows up again, but it sounds like it shouldn't from what you all deduced.

I'll post back with any updates. Thanks again! :)
1 - 5 of 13 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.