redish color in radiator?
 

Anyone know what could cause antifreeze in radiator to be almost like a salmon color? Went to check the level and its a weird color asked a mechanic and was told previous owner probably added some sort of stop leak additive. It does not look like rust. Any advice is greatly appreciated. Thanks in advance.

90 350 TBI

Re: redish color in radiator?
 

Is the additive dangerous to other things, seems like a bad idea to do this.

Re: redish color in radiator?
 

Likely the previous owner switched to long life coolant such as Dexcool.As long as system was flushed you should have no issues.If you have to add coolant be sure to use a universal type and not the green ethylene glycol.

Re: redish color in radiator?
 

Is it milky as well? Could be trans fluid mixing if it has a trans cooler in the radiator.

Re: redish color in radiator?
 

Stop leak is a bad idea most use it to fix a leaking head gasket,And its good at stopping up water passages and sometimes radiators.Look down inside the radiator does it look nasty and sludge or clean and smooth?

Re: redish color in radiator?
 

Dump and flush, refill with green ;)

Re: redish color in radiator?
 

Not milky. That was my first thought about trans fluid mixing. I'll get a closer look today. Thanks guys!

Re: redish color in radiator?
 

sounds like a stop leak or a mix of old and new type of rad fluids.
Flush ASAP
not likey tranny fluid,I'd think the higher pressure would blow the rad cap, no?