my coolant doesn't look right [Archive] - Forum


View Full Version : my coolant doesn't look right

09-11-2004, 04:18 PM
At least I don't think so. It's got this gunky brown stuff on the cap and around the top of the coolant tank. see attached pics...

*edit* Forgot to mention that all the coolant should be brand-new after UIM and LIM troubles last week. But t's been like this since I got it.

09-11-2004, 05:55 PM
I have the same problem, I have taken the coolant out, flushed the system, and flushed the res. gotten all that stuff out, and its all back now about 2 months later..

Its a very oilly substance, but it does not look nething like the Dex.
I could not bear the think of what the water-pump looks like if that is where it ends up.

I have not had the LIM changed that I know of, the car was used.

Did they clean out the res. after putting the new coolant in?

09-11-2004, 08:06 PM
I doubt it. If they did, they didn't do a good job of it.

09-11-2004, 08:47 PM
I have the same crap on the cap of my coolant tank. My car has 62k miles and I've never had the LIM replaced cause I've never needed it replaced. I hope someone has an idea but I think it's probably just the coolant breaking down and depositing on the cap.

09-11-2004, 08:54 PM
Make sure your radiator pressure cap is good. Dexcool doesn't like air in the system.
I've seen this same problem over at the Ls1 sites. Weak cap/weak or loose hoses or low coolant level will allow air to circulate and then the Dexcool will start to thicken up and get gritty. Hope you get it fixed soon.

09-11-2004, 09:27 PM
You have a bad Intake Manifold Gasket. It is a common problem & if yhe car is still under warranty for some of You take it in as it is an expensive repair!

09-11-2004, 09:30 PM
so THAT'S what an intake manifold gasket leak is supposed to look like! Finally a picture, after only hearing descriptions of it.

09-11-2004, 11:30 PM
Well... I wouldnt go on saying that 100% that its a LIM leak. Dex-cool normally gunks up a little bit and looks like poop... literally. But if its like caramel looking (like on ice cream) then you got some issues stan... i think you need some conseling.... err.... if it looks like caramel... then coolant is mixing with oil.

HOWEVER, dexcool normally gunks up a little bit and looks like #2.

09-12-2004, 06:10 AM
I did change the cap while ago....
Going to clean it out agian and see if it come back

09-12-2004, 07:11 AM
You have a bad Intake Manifold Gasket. It is a common problem & if yhe car is still under warranty for some of You take it in as it is an expensive repair!

Yeahp.....mine was doing the same thing. You could see a little bit of an external leak, but most of it was internal. Got it fixed. Oil was fine but the coolant looked like ass.

Hasnt come back...has been about 6K miles.

09-12-2004, 09:14 AM
I'm going to throw 2 cents in, yay! My issue was that I just flushed my moms coolant after I saw the gunk in there, so Ill tell you everything I saw. I really doubt her 60k miles has the leak, although sometime soon it may happen, and ill explain why I think that.

Ok, I saw that gunk in there, looked at the oil along with checking all the fluids because that is what I was set out to do, the coolant level was fine along with the oil level being fine, they were at the same level two weeks ago. I decided that the coolant was getting gunky and my coolant cap looked like image #1 up there. So I drained the system, used Super Flush stuff and flushed it out. The thing is that I realized when you clean the cap you will see the stuff come right back because I would put fresh water in there and all the gunk sticking to the walls of the resevoir would be floating off the sides and sitting there on the top of the water. Since it was sitting on top, when I filled it with water, it would come in contact with the cap and make it gunky again.

Either way, when I was flushing it I had no indication that there was any difference in color, texture, or gunk that would be present in a gasket leak. It looked like coolant, while looking at the coolant I didnt see any of the gunk in the coolant that I saw in the resovoir at all, so I figure that it was only just junk in the resovoir and not floating in the rest of the system. (Is that even possible??, its what seemed aparent though)...

The picture you have got for #2 isnt very clear, but since you say your coolant is new and you had your resevoir rinsed out too (I assume this means removed and rinsed clean), I don't understand how that could have gotten that way unless you actually do have a gasket leak. The only thing that I can really think is that your coolant wasnt fully flushed and/or the resevoir wasnt actually cleaned. I really hope your LIM gasket fix hadnt gone bad.

09-12-2004, 09:36 AM
I did have a gasket leak. I just got my car back last monday after having both the UIM and LIM fixed. I should've been more clear about that. I don't think the dealership rinsed out my system.

I've had the car for a year and a half, and it's always been like this. I'll see if I can get a new cap soon.

As far as the second pic being fuzzy, my camera sucks. Basically, the same sludge on the cap is on the tank (above the coolant level), and some of it looks like it's floating on top of the coolant.

09-12-2004, 10:59 AM
thats not whats a LIM leak looks like thats NORMAL, Dexcool does that it creates a Slime on the cap and in the engine. a LIM leak would be colant on your Oil cap.

09-12-2004, 11:02 AM
I had the exact same problem show up AFTER having the LIM gasket fixed for a leak. Before having the gaskets changed, the coolant was clean. I got it back from the dealer and noticed that although the coolant was clean, it had a few pieces of that dark gunk floating in the resovour tank. After a few weeks, it looked exactly like yours.

I went back to the dealer and complained about how it was dirty after having the gaskets changed and said that the coolant should be clean since new coolant had to be used to top off the level (they told me when the change the gaskets, they only top off the coolant, they don't drain all the old stuff out).

By complaining to the service manager, he agreed to have it flushed for free.

When I got it back from the flush, the coolant was once again clean. But after a few weeks it had more of that gunk (but not as much as the first time). I decided to give up on it now.

09-12-2004, 03:14 PM
[edit] nevermind

09-13-2004, 08:01 AM
Same here. My old engine gaskets leaked twice and one with the water pump. The coolant bottle is so yellow that I don't know what the hell is in there or how much. I asked them more than once to change the bottle with a new one. It's as if they where hidding something with keeping the old bottle. My new engine gaskets leaked the first week it was installed. Now, the water pump on the replacement engine is leaking. 102,000 Miles and I'm happy to simply have my GT !

09-13-2004, 10:41 AM
i was told by a mechanic that radiator shops should be able to put in an additive to the coolant to help keep it from breaking down and leaving this true? thanks.

09-13-2004, 02:28 PM
i had the same problem and replaced the gasket. now the coolant looks like new and has been that way for a few months now. my girlfriends dad is a GM Engineer and did it for me for free, plus parts ($80). good thing, i was told that i was looking at $500 to $600 at a dealership.