Brown slime floating at radiator cap- DEXCOOL AGAIN?!
 

Hey guys. I went to replace the radiator cap today since the current one was the original one for the truck and was very difficult to remove. When I finally got the cap off, I found BROWN SLIME floating near the cap. I looked into the radiator and saw some more inside sticking to the internals of the radiator. I used a paper towel and soaked up all the "mud" near the filler neck and put the new cap on. Here is the history of the cooling system of this truck:

58200: Radiator replaced-Was cracked and overheated on the way home from the dealership
~59000: Hoses replaced- Antifreeze smell, but no apparent leaks
~72000: Intake gasket replaced (coolant and oil were changed also)
~75000: Coolant flush (DEXCOOL- Valvoline refused to put the green stuff in AFTER they agreed to it before it was pulled in and AFTER they started draining it!!! I am going to call the Better Business Bureau on that. They even removed 3 labels I put under the hood telling them NOT to use DEXCOOL!)
88200: Radiator Cap replaced (today)

I am going to flush the coolant at the next oil change which is at ~89169.

Does this "mud" indicate a blown head gasket or something? The antifreeze looks ok (light clear neon orange) and the oil looks just dark honey brown (no milk as far as I can see). I posted a photo of the "mud".

http://sancarlosradiator.com/dex-cool_pics.htm

This is what I found. Is it possible Valvoline didn't do the coolant flush properly and the gunk is from 30000 miles of driving?

The *mud* in your coolant might be motor oil. Check your gaskets!!! :icon_hyper: Do a compression test to check for leaks!!! :icon_hyper: This happened to me when my Engine Block Cracked at 152K (severe overheating). According to your cooling system history, this might be the problem. Good luck Nerdy!

From the picture I believe the gunk is the build-up that occurs when air gets into the coolant and reacts with DexCool. Since the radiator cap was the original and probably no longer had a good seal it was possibly the cause. I recommend a Stant Lev-R-Vent cap.

That is exactly which one I replaced it with.

MOTOR OIL? Wouldn't that make the coolant milky? Wouldn't the oil on the dipstick be milky? If that was the case, wouldn't the engine be destroyed by now? I drove it a little hard yesterday in 90F weather both long distance at high speed on the highway and around towns with ALOT of steep hills for about 140 miles with not so much as a hiccup or gauges showing any different to what would it would be at freezing temps. These were just brown mud particles floating. The same stuff was stuck on the internals of the rad. It was just like the photos on the link I posted, but not nearly as bad. I have never had to add coolant either. The car has also been to several places to get the oil changed over the past 2.5 years. Surely one of them would have noticed a problem? Time for a flush with green?

P.S. They did a pressure test on the cooling system when they went to replace the hoses after we smelled antifreeze AFTER the radiator was replaced. They told us the intake gasket was going bad at the time, but it wasn't giving us problems. When I started noticing antifreeze starting to drip from the front of the engine behind the A/C compressor when the engine was running and cold, I had it replaced.

Oil in the radiator makes a muddy sludge. I don't really know why my oil was clean, but it was. I wish I had pictures of my antifreeze...it was gross! If Memory serves me right, it was like a mixture of gravy and coffee grounds! My block was cracked near the cap / rotor, facing the firewall. I drove 10k more on that truck before I sold it, and the person I sold it to still has it on the road...IDK?!?! My mechanic *advised* me to keep the trips under 100 miles, in fear that more damage may be done. Where he got his numbers still baffles me! I drove and performed fine, even with the gash in the block!

I know that coolant (water) in the oil makes it foamy and milky! But that is usually from a blown head gasket.

Location, Location :icon_shrug:

Could the air be more likely because before I had the coolant flush I was hearing gurgling coming from behind the dash sometimes during acceleration. After a couple trips after the flush, it went away. Never heard it again. The antifreeze itself looks okay. It is the brown particles that I am talking about. I just removed the cap again and there was more there (see photo). I could also see the brown sludge stuck to the steel internals that are just above the trans return line fitting (which is hooked to the aux trans cooler)(see photo).

I also did an experiment and combined new 10W-30 oil that was left over and new (from a sealed bottle) Prestone 50/50 Extended Life coolant and put them in a large plastic cup. I put the oil in first. The oil still looked okay (since it floated on the antifreeze), until I used a plastic fork to stir the mixture to simulate engine operation. Needless to say, it was the consistency of water, it was foamy, white/brown/yellow and it stuck to the fork. I even took 2 paper towels and swabbed the dipstick from the engine (conventional 5W-30 with Lucas with ~1750 miles on it) on it 5 times (left) and put it next to a paper towel that I swabbed the fork onto it 5 times (right) just to see what my oil would look like if my engine was completely destroyed if the oil was like 1/4 antifreeze. Even though I added alot more oil to the mix later, the color didn't change. The results are in the photo.

Please understand that I am very concerned about this and I am just hoping that it is the DEXCOOL sludge and not any problem that can't be fixed by flushing with green at the next oil change (in 750 miles). Can anyone point me in the right direction to a site that says how to do a complete flush (to convert to green) if I decide not to pay $120 for a shop to do it? Thanks for understanding.

the oil cooler or trannie cooler in the radiator can leak mixing the oil in the radiotor itself,


if you are dead set on getting rid of dex-cool use prestone global dont go with the green

Radiator leaking internally? How can that be if it is new? Is there a chance it is just DEXCOOL causing sludge? I haven't had to add oil at all (sometimes it is overfilled actually) and there always seems to be a drip of a couple drops a night in the garage. But I have yet to add oil to this truck. It always seems to stay in the upper 1/3rd of the operating range on the dipstick.

Also which antifreeze should I be using? Is it this one? http://www.autozone.com/autozone/cat...dName=Prestone And also is this the procedure I should be following? http://autorepair.about.com/od/regul...lant_flush.htm I just want to make sure. The last thing I want are more expensive repairs.

P.S. I hate to press this matter further with senseless questions, but will a piece of 1/4" PVC tubing fit that drain fitting? It seems that there is a plastic valve and a fitting that drains toward the passenger side of the car. What I want to do it hook up the tubing to the drain fitting and put the other end of the tubing in a 5 gallon bucket since I currently do not have the means of raising the vehicle and also since I do not want to cause a mess since our little dog likes to run into the garage every time I open the door and I don't want a mess that he can try to drink. I don't want any accidents and I want to do it as neat as possible since my mother is a neat freak (I am home for the weekend.).

If you arent getting grey or white buildup on dipstick or oil filler cap I dought if you have a water in oil problem. If truck is not overheating I dought if radiator has a problem.. When you replace old hoses and other parts you get old sludge breaking lose and floating. Just keep a eye on it and drive !!