Hey Guys,

I popped the coolant cap to check my coolant level on my 4runner;

1990 4runner, 3.0L,Manual, 200K miles.

I found this weird thick gunk under the cap. I reminds me of clay, it is thick.

My coolant is still the nice green color. Oil is clean. No overheating or smoke at all. Coolant and oil level has not dropped, I've been monitoring it since I noticed this.

Is this a HG or a coolant issue? I have seen similar stuff with GM's Dexcool.

Pics;



Thanks in advance,

Logan

 

How long has it been since you last checked it?

 

I think when I bought it. And it has some light brownage then but I chalked it up to old coolant, which the PO had all of the fluids replaced by a Quick Lube Place. But now I noticed more after. The vehicle had been sitting for a couple years before he changed the coolant.

 

I don't know how long ago you bought it lol
All I can say is flush it out really good and don't forget the heater core and if you have rear heat. Then just keep a eye on it

 

I'm gonna flush it. I bought it 5 months ago sorry haha

 

yup. flush it then get back to use in a few weeks.

 

....and after the flush, use Distilled Water for the final rinse and when making your coolant mix. Don't use tap water...the minerals can do nasty things.

 

You could run some RMI-25 coolant additive. Good stuff and cleans the system out gently. I run it in all my cars.