Very important that we get the year and engine with every post.
Could be stop leak, could be a cracked cylinder head, (especially on 00-01) could simply be a very abused cooling system.
It is a 97 4.0L with auto trans.
The coolant looked good when I bought it, and I have put 20,000+ miles on it with no problems (now 120,000+ total).
My oil, trans fluid, and PS fluid look decent and I don't have abnormal amounts of usage of them.
I will flush it out this weekend and run distilled water for a week or so. I don't have to worry about freezing temps and I'll put a quart or so of coolant in for lubrication of the water pump. After a week I'll flush again and use distilled water and coolant per the owners manual.
I have just never seen anything like this so I thought I would see what the experts think.
Thanks
Shorty;245590033I'll second the replacement of the HO pump and thermostat-- they don't like all that gunk any more than the radiator.[/QUOTE said:I agree. And a new radiator cap to boot. None of those components are particularly expensive.
You might want to run a chemical flushing agent through your cooling system before you install new parts though to get rid of the lions share of the gunk.