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GTOholic
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Discussion Starter #1
I'm spending a quiet Sunday morning with my GTO. This is almost better than "pillow talk."

I see a large amount of black sediment in my coolant tank. The sediment is floating in the coolant and clinging to the sides of the tank. The sediment is about the size and consistency of black pepper. I think it might be "paint flakes." Does anyone else see this sediment? Does anyone know what it is? I doubt it is harmful, but I would like to know if it is a "problem sign." Thanks.
 

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Captain Thread Killer returns
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FLORIT said:
I'm spending a quiet Sunday morning with my GTO. This is almost better than "pillow talk."

I see a large amount of black sediment in my coolant tank. The sediment is floating in the coolant and clinging to the sides of the tank. The sediment is about the size and consistency of black pepper. I think it might be "paint flakes." Does anyone else see this sediment? Does anyone know what it is? I doubt it is harmful, but I would like to know if it is a "problem sign." Thanks.
I think I have this too, I was thinking mine was from the sealant tablets the dealer put in to fix my freezeplug leak. However it maybe something else.
 

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-Tom Capozzi- Spitzer Pontiac GMC
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It could be residual casting sand from the molds.GM has had problems in the past where there was so much sand in the coolant passages that it was plugging heater cores.Unfortunately there's not much that can be done other than to have your dealer continually flush the system until they can get it all out
 

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Yes, it has a car seat
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Well, there is the old 'used car salesman' trick of using black pepper to fill pinhole radiator leaks...
Dan
 

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-Tom Capozzi- Spitzer Pontiac GMC
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DANSLS1 said:
Well, there is the old 'used car salesman' trick of using black pepper to fill pinhole radiator leaks...
Dan
We hardly ever do that anymore!!!LOL
 

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Snagging your fish!!!
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that bites guys, lets hope it's not sand circulating around in there.
 

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tommycap30 said:
We hardly ever do that anymore!!!LOL
Actually, in my 1978 mustang ii I had in high school, I developed a pinhole leak in mid-January. Being a senior in high school (ie broke) and having -10 high days, we did the pepper trick. It actually went a year and 1/2 and busted the whole seal on the top of the radiator.

Now, I haven't noticed any sediment in the antifreeze, but I did notice some 'gummy' dark grey sediment in the clutch hydraulic solution. It was on the top around the edges and wiped out pretty easy, but was kind of weird.
Dan
 

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GTOholic
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Discussion Starter #10 (Edited)
I gather from everyone's input that I should have the dealer at least flush my cooling system. This bites. The car goes in the shop Tuesday (tomorrow) to have the hood repainted, and I'm leaving Friday for "Pontiacs In The Park." It may be next week before I could have that done. The car is running fine. Do you thing it is safe to take it on an 800 mile road trip?
 

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I dont use Dexcool anymore since it leaves a grey colored sediment in the tank. For a coolant thats rated for 3 yrs, it turns "off" pretty quick.

After 1.5 yrs of driving, it came out looking dark red/orange color instead of the blood red you see when new.

I have since switched over to Pri Max. When I changed over, Ive noticed my coolant temp is consistently lower than with Dexcool and it is cleaner looking inside the coolant reservoir.

I change coolant once a yr.
 

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GM (and other automakers) use "long life" coolant (aka DEXCOOL) in their new cars. Simply put, it's total garbage. It becomes thicker with use, and collects as hard buildup in the cooling system.

You're best off to completely flush out the cooling system, and use regular green engine coolant. I've done this on all of my late model GM vehicles with no problems.

Just be sure not to mix DEXCOOL and regular coolant.
 

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I was thinking. (watch out) If the sediment is floating, it is going to the highest spot in the cooling system. The coolant tank. It might just be some by-products and it might only be in the coolant tank.
 

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Dexcool issues??

I do agree abut not letting dexcool last 5 years and GM says in my personal cars. 2 things, however, I do on my GM vehicles with dexcool: I check the radiator cap very frequently. Getting air exchange with a non perfect radiator cap does assist in the formations of contaminants. But I think one of the biggest issues iwith Dexcool is the interaction of normal chemicals in regular tap water. When doing a coolant flush on my vehicles, I will only use distilled water. It is really cheap, and I think it makes a difference.We have too many coolant contamination problems and leaking intake gaskets on multiple GM engines. Taking these precaustions can't hurt. If you do not bleive me, ask owners of some 1996 V6 engines with 10 pounds of red mud in their coolant system.

If you are going ot have the dealer flush out your coolant system, bring them the water, and insist on them using GM bottled Dexcool only. I do believe this is one of the reasons many of the foreign car manufacturers like Acura that sells you thier long lift coolant alreay premixed at about $14 a gallon!! Not all bottled Dexcool is equal. The GM stuff is by far the most expensive, but GM is paying for it, and it is the best stuff. Also make sure they put in the correct amount of Dexcool.
I do aggree with previous posts that a little sediment in the bottle would not cause or alarm me.
dms
 

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May I quote you on that?
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Speedy Gonzales said:
I dont use Dexcool anymore since it leaves a grey colored sediment in the tank. For a coolant thats rated for 3 yrs, it turns "off" pretty quick.

After 1.5 yrs of driving, it came out looking dark red/orange color instead of the blood red you see when new.

I have since switched over to Pri Max. When I changed over, Ive noticed my coolant temp is consistently lower than with Dexcool and it is cleaner looking inside the coolant reservoir.

I change coolant once a yr.
What's Pri Max?
 

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Cooling System Leak Prevention

I've heard that just about all vehicle manufacturers add a sealant to the coolant of new engines as a precautionary measure in case there are any leaks.

Anyone else know anything about this?
 

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I've heard that just about all vehicle manufacturers add a sealant to the coolant of new engines as a precautionary measure in case there are any leaks. Anyone else know anything about this?
My 05 GTO has this same pepper looking sediment but it looks exactly like the material within GM cooling tabs. From my experience the GM cooling tabs do a good job of stopping small leaks and I have always used them on my GN whenever I have had to tear into the engine. I would have to say that what you are seeing is just extra material that has not found a home (leak) and is pretty much harmless. Thats my .02
 
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