Coolant Gunk [Archive] - Forum


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03-10-2004, 09:41 PM
Hey, today I checked my engine coolant because my "check engine coolant" light flashed the other day. When I checked it out I noticed there was this orange gunk build up on the inside of the cap. I was wondering what this was from and if I should check it out. One last thing, where can I pick up that Dexcool stuff, any local auto part store? Thanks

Mike Jung
03-10-2004, 09:55 PM
Originally posted by playerx4
...One last thing, where can I pick up that Dexcool stuff, any local auto part store?...

Pick-up some Havoline Extended Life antifreeze that is GM spec'ed 'Dex-Cool' at an auto parts store.

GM Dex-cool: Who makes it? (

03-10-2004, 10:33 PM
i have a little bit of buildup on my cap too, but i dont think its a big deal. my coolant looks great in the tank, if thats gunky, you have a problem and stop driving.

03-11-2004, 02:52 PM
The coolant in the tank looks a little gunky... What could have caused this, my car only has 35k miles on it. I will go get it flushed tomorrow.

03-11-2004, 04:02 PM
Its normal. Happens to everyone.

03-11-2004, 09:48 PM
I'd really keep an eye on that. Check your engine oil and keep on eye on it when you change it. You could have the infamous leaky intake gasket

03-11-2004, 10:56 PM
The gunk he's talking about is normal. If it's oil, trust me you'll know. This is the normal gunk. Has to do with dexcool and manufacturering and such. I don't wanna get into it. Just know it's normal with Dexcool. Just clean it is all.

03-11-2004, 11:12 PM
I really meant keep an eye on the "low coolant" lights, i havent had one since i've replaced my intake gaskets

03-13-2004, 08:01 AM
I have 55,000 on my 2001 and I just cleaned the resovoir as well. I got a little nervous at first but then I researched it out and it is normal. I cleaned the cap and then used Q-Tips to get the build-up off of the inside of the resovoir. I will probally change the coolant at 60,000 and then I intend to take the resovoir out and give it good cleaning in my slop sink.

03-18-2004, 02:50 PM
I had the same problem about a year ago. I drained and flushed the coolant and replaced the reservoir. It had the orange gunk built up a few months later. I did research on the leaky intake manifold leak and checked out my engine for any leak around the engine. I couldn't find any leak. The oil looked fine too. I decided to take it to the dealership and they indeed discovered the leak as internal and oil was making it into the coolant system. The funny thing was coolant was not going into the oil. So oil was causing the slimy gunk not the coolant breaking down. I had them do the gasket repair and its been over a year and no orange gunk is in reservoir.

03-18-2004, 03:59 PM
if you spend a whooping $50 a year at an independant garage to have your system pressure tested and flushed, you shouldnt have any problems with build up or dirty coolant.... or at least before every summer season :thumbs:

03-18-2004, 04:24 PM
I have a question for yall.. Seems kinda ovbious but I was wondering. My coolant resevior is almost opaque white.. :wtf I cannot see the coolant level at all even though it is at the level its supposed to be according to my last oil change. I think something happened to the plactic or it was just a bad batch, but even shining a flash light against it I can't see the level, just a red tint, are yalls like that or are they clear enough that you can see the level of liquid in the tank? I'm thinking about buying a new resevior, but I don't want to waste my money if its going to be the same.. I would think it is important to be able tell if your coolant level is at the arrow though.

03-18-2004, 04:32 PM
my 2001 has the orange dexcool

where as my 2003 has a lighter colored resivoir, and supposedly GM dropped the dexcool for a *pinkish* looking coolant.

that might be the red you are refering to

03-18-2004, 04:36 PM
Yeah, Color isn't the problem, I was just saying that the plastic that the tank is made out of has been opaque since I got the car and I can't ever see the level... I was looking under the GTO's hood at the dealer and it's tank was pretty clear (could easily see the coolant level) so it got me thinking about it

Edit: I drive a 2002...

03-18-2004, 09:06 PM
I want a clear resevoir. Can someone let me know for sure if there is one off a newer GA. A pic would be awesome. I have the old solid plastic one that you can't see **** in.