Whats the best method to test if coolant is still good in a car thats sat? I read that a multimeter can tell if its corrosive if above .04V. Any other tips to tell if it needs replaced? Thanks

 

Test strips are available by Baldwin and others. If you'd guess it to be more than 4-5 years it would be best to change the fluid than testing. IIRC, about 3:years is the suggested change interval.

 

Most have been sitting longer than that. 🤣

 

That’s for an engine that has been running, right?

I’d drain and fill, but was just curious about a vehicle that has been sitting.

 

Good question, I don't know. Hopefully one of our chemistry guru's chimes in. Norm?

 

Depends, new coolant is 5 years plus the past number of years. Depends on many factors. I would look at it in a clean container. I bought a $50 1976 Cutlass that sat for a couple of decades. The coolant was mud and actually ate through one of the factory shim head gaskets. If you change it, pull the block drains.

 

Unfortunately, no clue.

 

I'm no chemist, what I do is look at the color and if there is any corrosion or buildup in the radiator. If it is the usual pretty green color and the hydrometer shows that the freeze point is in range, I consider it all good.

 

I recently bought test strips at O'Rielys. They were behind the counter... I was mostly interested in PH and not freeze protection but it does both.

 

Yup!!👍

 

What coolant are we talking about? Traditional green coolant is different than DexCool which is put in later model Oldsmobiles (my 96 98 used it). Also, the coolant used in my 86 Ford truck has SCAs in it and has a yellow tinge (probably suggested for diesel Oldsmobiles too).

Don't forget that test strips and coolant testers are dependant on what type of coolant it is.

Good advice given above though. DexCool and SCA charged coolant are even less tolerant of sitting for years and years.