Casting Sand in Radiator....Anyone?

Recently I took my 2000 xj on a road trip about 3 1/2 hours long and when I arrived at my destination I noticed a stain from what looked to be like rusty liquid down the passenger side of my xj. I looked underneath and noticed it was all over my back tire and inside the engine bay. Upon further inspection I noticed it looked like it was leaking from the thermostat housing and hitting the fan causing it to go all over. My thermostat was not fluctuating at all on the trip. I purchased a new housing gasket and thermostat and new antifreeze. I brought my truck to a mechanic to have them do a flush and it all in one shot to minimize any rust getting into my parts.

The mechanic said he flushed my radiator and thinks that there still may be casting sand from the factory in my block. He said he flushed it using the machine and than using water going; until he saw clean water. He than filled it up with coolant and when I picked it up my coolant in the resevoir was still a yuck color. He told me that I need to continue flushing it; possibly try using a cup of spic n span cleaner into my coolant and than driving it for a day or 2 to let it cycle through and than flush again. Does this make any sense? Has anyone heard of any problems like this before?

If you've gotten this far I thank you; sorry to write a book but I'm trying to give as much info as I can. Any ideas would be awesome.
thanks for your time

John:idea:

casting sand in the block??Unlikely......corrosion from the previous owner not maintaining the cooling system.Likely

even if there was a little bit of casting sand left in the block it would probably be very little and would have been removed when the first cooling system flush and fill was performed(assuming one ever was done).Get some prestone cooling system flush and drain the coolant and put the flush in there with distilled water and drive it.(follow directions on the container)
cider vinegar is a good flushing agent also.....

John,

When I did the first radiator flush on my 2000 I found a couple shot glasses full of sand like material (???) in the overflow tank and the drain bucket I used. I flushed with a lot of clear water and refilled. That was a few years ago and lots of miles. So far no problems, the water pump still seems to work and the temp stays cool. I wouldn't worry.

that sand was the silicates in the coolant, it can "precipitate" out of solution over time. It normally stays dissolved, when the coolant charge is fresh.

newer coolant formulas usually say "low silicate", to prevent this stuff from building up, and causing corrosion.

The only engine I ever saw casting sand in was a 75 Dodge 360 and the sand was in the crossover on the intake manifold, prevented the choke from working property, choke spring was in a manifold pocket, played hell in the winter.

If the truck did have a PO he may have been a DA and put stop leak in it when that stuff finally does break down it looks like your hole engine is rusted out. Brown anitfreeze. Atleast that was the exp. with the 98 blazer I owned that the PO used it in

Vinegar/distilled H20, flush (distilled) refill 50/50 or coolant /distilled

dizzymac said:

Vinegar/distilled H20, flush (distilled) refill 50/50 or coolant /distilled

Click to expand...

X2 on the vinegar. Also, remove the overflow bottle and clean it good while it is out. I have found the best method to be put a handfull of small rocks in it and shake it. Don't shake it so hard you break it, but it will be abrasive enough to get all the crud off the sides of the bottle. Make sure to rinse well and get all the rocks out before you put it back in.

X3 on the silicates.

Tap water vs distilled does matter. I thought that was bull until I saw it happen within six months. I went with distilled and used the same brand antifreeze, end of problem.