what is this goo?

[andy d]

im starting to get the wag ready for winter. the radiator is a 5 yr old modine 3 row. i think ive solved the leak mystery and got the expansion tank working too.fixing this raises another question, what is the white goo around the top of the tubes? its not hard, it feels and looks like joint compound, not the rust and crud i am used to seeing in radiators and cooling systems. my well water has a high iron content.i havent back flushed the system lately but i plan too. i am considering using a flush or cleaner. which is better? please advise, TIA

[Damage, Inc.]

If you're prepping for winter, I'd take the radiator out and take it to a shop and have them rod it. It's usually under $100...well worth it.

[OBX-AUTOMOTIVE]

OIL? I LIVED WITH WELL WATER FOR YEARS!!.. I HAVE NO IDEA!! FLUSH AND TRY BOTTLE WATER!! GEEEZ IT'S ONLY,TEN ZILLION DOLLARS AN .OZ :rolleyes: :D smile.gif

[beater]

sounds like oil to me

[DerJeep]

Are you using regular antifreeze or the extended life orange stuff? I have a newer Blazer that came from the factory with the orange stuff that is supposedly good for 100,000 miles or 5 years. The stuff is crap and developed the white goo you describe. There have been many complaints about the stuff.

[phil king]

The white goo you describe could be the antifreeze your using as for flushing the radiator have it done proffessionally the stuff they sell in the auto parts store wont do as good a job

[mccullough_89_GW]

but back flushing it yourself is better than just changing the radiator fluid only.
.nice thing about the shop is they use air pressure bursts to really knock the crap out, and gets the heater core also....I don't like to pay for it unless it is necessary...and i haven't owned a car yet, that I felt it was necessary to pay someone for a backflush...i just do it my self with the prestone kit...
could the white stuff be a reaction of the metal/and radiator fluid/heat???

[andy d]

i did use a little of the orange stuff. i have been running the drainings from my bmws in it as it was using about a gallon of coolant a month. thought the leak was the pump. it turned out to be a loose clamp. so now the its time to flush the system. i have a flushing tee installed.i back flush every 2 yrs or so. just water. but i would like to get the goo out. BTW, Beater, no way its oil. oil looks like a chocolate shake.AMHIK :D this is just little piles of white stuff collecting around the tubes in the top tank. any way, thanks all for the feed back