Coolant deposits

[katit]

2002 Seville. It's leaking coolant. I checked and it seem to be coming from pump area but didn't investigate further yet. Car leaves drips on a floor, so it's not coolant loss that just evaporates..

Anyway. I looked inside expansion tank and found that inside there is witish almost like a mold-looking deposits on a walls. Coolant looks clean and clear. Same with deposits. No dirt or stuff in a fluid.

What is that? How do I get rid of it?

I will probably be taking care of leak (either it pump or water manifold) and I just want to give system good flush.

Car has 65k miles.

Thanks!

[chubbyranger]

It may be the remains of the GM coolant supplement tabs, basically factory Stop-Leak. I can't remember when they stopped using them, if you search enough posts it should be here somewhere. If you drain and refill the system you can remove the surge tank and rinse it out, but I wouldn't go nuts trying to get it perfect since you should add the tabs or powder when you refill the system if your car is supposed to have it. Look for a sticker on the radiator cowl under the hood - there should be a reminder to use the tabs if your car is supposed to have them. My leak turned out to be the water pump but there are a few suspects in that vicinity.

[creeker]

Dont all the N* require the tabs?.

[JimD]

As mentioned, you could be seeing evidence of a factory-fill coolant supplement (insurance for nuisance leaks). However, the supplement usually shows a brownish residue when it drops out of solution. Nothing to be concerned about. In fact, a visible collection of brown residue in the coolant reservoir is a good sign as it is an indication that the cooling system contains 'at least enough' supplement to do the intended task.

Do not expect to be able to "flush" the supplement residue from the reservoir. Coolant flow through the reservoir is from top to bottom; the design is intended to purge air from the cooling system and permit the air to remain inside the reservoir while the head of liquid coolant is maintained for the remainder of the cooling system. To accomplish the air purge, the reservoir is constructed in a baffled, or honey-comb, design. There ain't no way you can effectively "flush" the thing.

And, coolant loss at or near the water pump can be either the water pump O rings or the water pump cover seal. Or, worst case, leaks in that area can also be the crossover seals.

[Ranger]

Originally Posted by creeker

Dont all the N* require the tabs?.

GM stopped using them in '01 or '02 I think.

[Murphyg]

They are still required in 01s. Is what I have, and it says its required right under the hood. I actually had an argument/well discussion to be exact, with the Service Manager about it. He swore up and down that in no way or no how does or "DID", GM "EVER" authorize and or recommend the adding of anything in the coolant.
He did though look into it "After" my service was done and called me to tell me that I was correct.
That call was on my answering machine four days after my service.

My wife informed of the message at the same time I walked in the front door pissed right off because my car was leaking coolant on the street in front of the house !!!!!

No word of a lie, The Service Manager ! The One In Charge. Tells me that they do this all the time. They have done thousands of them ! And they have never added the supplements.Turns out the boss didnt have a clue LOL. Not to mention the fact that when I brought up that it is written right on the cowling; He had the audacity to try to pass it off to the mechanics for never saying anything about it ?!????? They never noticed and nothing was ever said to me etc..etc....total pass the buck and denial of complete incompitance on every level.

So with that said.
Turns out that my water pump was now leaking.
And no matter what anyone says to me. Its just too much of a coincidence that my water pump would suddenly begin to leak right after receiving a coolant flush. Absolutely no drops, not even a trace of moisture what so ever, until immediately after the flush.

Which was done incorrectly to GMs recommendations I might again add.

So back to the water pump issue.
I was told that there was/is an issue with the factory installed pumps. (Again talkin 01s for sure. But is still the same chance it is also 02s).
There is a redesign. Redesign is not the exact term that I was given. But when explained it is what they mean.
So I said its a recall then.............They said "NO". They have just redesigned it because its not as good as it can be. It is not a recall. But the new replacement pump is better.
Guess its only a recall if there is the possibility of something life threatening to occur upon failure. If its only the matter of costing the consumer out of there own pocket, then all is good and its looked at as though everyone is coming out even LMFAO .

Chances are thats why your pump is leaking.
So I would not consider getting an after market. Or even a re-build for that matter. Go with GMs new pump. Get it from GM. Cause no way to tell what design the after market manufacturers are copying.

[Ranger]

They are still required in 01s. Is what I have, and it says its required right under the hood.

I guess it was '02 when they stopped using it then.

Guess its only a recall if there is the possibility of something life threatening to occur upon failure.

Correct.