White Slippery Film in radiator? Any .....

ideas?

Truck now has 123K, regular servicing with a radiator flush not yet 2 years ago. Well, not too long ago, I was having problems with a leaking/bad reserve tank - so I changed it out, put a new one in and added about 2-3 inches of antifreeze to bring it to the minimum mark. Few weeks later, the new reserve tank cracked a leak as well - same spot, on the bottom where it screws into the truck.

Got a new reserve tank and again, added a bit of antifreeze. Well, I "thought" :banghead: that I had bought a bottle of PRE-mixed antifreeze/water. Turns out, it dawned on me, 4 months later while moving stuff in the garage, that bottle was straight antifreeze.

Immediately I knew I probably through off the ratio and had too much antifreeze in the system. Sure enough, through testing the antifreeze, the tester said I had way more than 70% percent antifreeze.

Crap, so I dumped the reserve tank, and added in straight distilled water, along with drawing some antifreeze from the neck of the radiator and putting water in there as well.

While doing this, I noticed white slippery film floating in the radiator. Is this from having too high antifreeze concentration?

I've had no cooling issues or problems. And unfortunately, I don't really have the funds to have a thorough flush/fill done until August; however if it's something bad, I'll do it soon.

You might have a slight head gasket leak if you are blowing out overflow/degas bottles. Combustion gasses will leak into the cooling system & overpressurize it. Engine oil could also get into the coolant with a head gasket leak, leaving behind the goop you are describing. Idle the truck with the radiator cap off to see if you are getting any gas bubbing (indicates failed head gasket).
G/luck
Joel

Rodeo02 - Are you saying oil in the antifreeze is the only reason for white gunk???

Also, the 2 reserve tanks that I had used/broken were used/old from the junk yard, not new. Thus I wasn't too concerned about them leaking to begin with.

I did have some bubbling effect going on, but I had also created some air in the upper hose by syphoning out some antifreeze off the top of the radiator. This two would create a bubbling effect till the air is removed, right?