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Brown gunk in radiator

M

MJM_Tex

NAXJA Forum User
Location
San Diego
PUwZAVZa


I'm going to flush and use new coolant and distiller water (vehicle is new to me).

Runs fine, oil and tranny fluid seem fine. PS fluid is ok too. Just wondering how radiator coolant can get so crappy.

Thanks
 
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.
 
Aside from the obvious baby crap..maybe PO mixed orange / green?
 
birchlakeXJ said:
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.
Click to expand...

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
 
Do your self a favor and replace the radiator. You won't get it all out. Mine was like that when igot it. I eventually had to replace the whole cooling system.
 
MJM_Tex said:
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
Click to expand...


Could be oil contamination as mentioned.

Could be electrolysis.

More likely its just stale, coolant, anti-corrosive additives, and the eth-gly is eating stuff.

Would probably be worthwhile having a look at the condition of the water pump impellor.

LOTS of flushing or a professional clean and rodding may work for you ...
 
you might get lucky with flushing or professional cleaning, but by the time you pull it for cleaning or buy repeated jugs of flush, you'd be dollars and time ahead with a new radiator.

I'll second the replacement of the HO pump and thermostat-- they don't like all that gunk any more than the radiator.
 
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.
Click to expand...
 
Hmmm, that looks extremely familiar.

I bought this 98 Cherokee for my wife at the beginning of last year. It's never run hot, never had an issue with it. When I bought it it had nice clean coolant. I've never mixed coolants and I've never put anything in it but water and coolant. I have no idea what caused this. Time and rust, I'd guess. It ran hot one day last week.

I pulled the cap and saw this:
2012-02-15_17-46-38_732.jpg


I flushed it several times, filled it back up with coolant and thought it was good.

The next day my wife drove it and the water pump started spitting coolant.

I went straight to the parts store and paid $189.95 for a new Radiator, water pump, thermostat, gaskets, t-stat housing, and both radiator hoses. Not a bad price for all of that. Installed all of that, flushed it a couple more times and it's been good for the past couple days. It's time to check it and flush it again tho.
 
That's frightful looking.., sheesh!
 
Just did work on a 99 with the same issue with the coolant.

His head gasket was blown and when he overheated the motor all hell broke loose.


Im not sure what happened first, the coolant disaster like you have or the head gasket leak.
 
I had a person come in the shop with his xj for heat issues and opened the cap, looked just the same, and it smelled like burnt coffee beans. End result the electrolysis had ate away the water pump impeller to just nubs. The coolant level was maybe half way through the block. I was really surprised that it had gone that long. we just replaced everything that could be replaced besides the heater core just ran a hose through it.
 
As many others have said had the same problem. Mine was so thick it was clumping when I flushed it out. I was lucky and worked where we had a huge boiler so I ran steam through everything that I could. Still had to replace the water pump and the thermostat. And when you flush the engine make sure the thermostat is out.
 
Where is the petcock on this thing and how do you get to it?

Looks like everything is blocked off by the skid plate. Any tips?

Thanks
 
Remove passenger head light bezel and it should be right there.
 
Don't use the petcock. They are under-designed and prone to failure.

Drop the lower hose as mentioned. Easier and safer. Have a big catch pan ready though and get your beak out of there when the hose comes off or you'll have a face full.
 
If it was not overheating and having a problem I would leave it alone. If it ain't broke don't fix it, LOL!

I have seen far worse looking than that run fine for years (7-8 years, and they were MINE!!!! LOL), and it was radiator stop leak additives that made them look nasty, and nothing else. And I have seen half the experts here at Naxja, self proclaimed cooling experts (LOL, I can feel the heat already, LOL), throw multiple wallets and hardware at their jeeps for months trying to solve real cooling problems with little success at times, LOL!

Also, do not try and run it with just DI water alone. Big mistake, it will boil over for sure. And DI water alone is very corrosive.
 
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