Drained radiator!!!

[kh971]

Well I have been having some trouble out of my 2004 550 and I have been some coolant. I decided to drain the radiator and I found brown grit in the radiator.
Any ideas what this is?
There is no oil in the fluid.
Any ideas?

[69cj]

Casting sand mostly. That's why I preach the coolant filter sermon. I just flushed my system 2 weeks ago and the coolant was crystal clear with nothing floating around or in the bottom of the drain pan. This included coolant drained from the pet****, lower hose and block plug. Filter was put on when the truck had 3,000 miles on it almost 5 years ago.

[boomboom]

Make sure you flush the whole system. Pull drain plugs from engine also, you wont believe the gunk that comes out. dieselsite.com for coolant filter system should be manditory on all. But its always best to start with a clean system first. You might have to flush multiple times to get clear water though. This could save you thousands in the long run.

[69cj]

If you read Fords flush procedure, you need to drain, add 2 qts. VC-9 iron cleaner, top off with distilled water and drive or run for approx. 1 hour. I just took mine for a 20 mile freeway drive. Then drain and remove t-stat. Refill and flush 4 to 5 times with distilled water till drain water coming out is as clear as water going in. Replace t-stat with new O ring and add 1/2 cooling system capacity Ford premium gold or Zerex GO5 coolant and then top off with distilled water. You will then have the perfect 50/50 mix. You will need to drive it a few times to get all the air out of the system. Just keep an eye on your degas bottle. The VC-9 is 26.50 + tax per qt. Not cheap but a requirement by Ford.