Either this weekend or next I'm removing my radiator to replace accessory belts and to do some other 'fun stuff'. I'm doing a little experimentation and will report results afterwards. J owners might be interested in it. Two questions:

1) What's the best coolant combo to use with Kentucky weather and how much distilled water am I going to need? I know Fred must have a detailed opinion on this one.

2) Is there anything I should be looking for while I'm under the hood this time and have the radiator out?

My current fill in a Q45 which has just a smidgen under 11 quarts coolant capacity:

70% distilled water3.5% redline wetter water26.5% antifreeze/coolant

Actually in summer if one wanted to improve your coolant heat capacity/flow even more one coul go down to 20% antifeeze.

The more water and les antiffreeze the more likely colant is to boil, but the less likely it is to get there in the first place.

The main reason manufacturers are now going over to recommending 50/50 is becasue they dont trust the average consumer to change his coolant as ofetn as is need with a thin mix (ie low on antifreeze/coolant and hi in water)

Fred...

I am toying with the idea of leaving that mix in even thru the winter as its still good well into the minus 20's and it hardly ever gets that cold here even at night.

Also the mix doesn't immedately freeze as soon as the temp drops below it's freezing point, it can take many many hours for the coolant to assume the out side temp even approxiamtely.

And it takes the loss of A LOT of joules for water at 0C to turn from liquid to solid.

So even a thin mix is pretty safe in most climates that dont have a combination of very low temps and hi winds to accelerate the cooling out process.

Having said all that I will probably get nevous come December and switch to a 57-60% dist water to 1 bottle redline wetter water and rest antifrezze.

Fred...

I guess one more question:What kind of coolant does everyone recommend?

If water pump life is important then you want an all organic additive package [no silicates, no phosphates, no borates, no sodium nitrites].

You must read the contents carefully as many are now making the red/orange [so called extended life] with the same old garbage formula........its 10 cents cheaper to use the inorganic than the organic acid additives. Yet they get to charge $2.00 more for the coloring!!

Actually if you change your coolant every 12 months/15,000 miles as long as it doesn't contain silicates almost anything is ok.

What happens is people get mix and match in coolant overflow bottle to replace the evaporated coolant [the water part] and different brands with different additives may interact chemically!.....causing who knows what!

Want to see something scarely when the rad is out for cleaning remove and look inside the brass colored metal hose/pipe that combines the lower rad hose and the upper return hose.......this is the anode to take corrosion instead of the block and radiator.

When you remove the radiator always get replacement foam air blocking surrounds to replace the worn ones .....this bypass air causes many problems as it is easier for the fan to suck air around the rad than to pull it through the dirty condenser coils.

Dennis,

What brand of coolant do you use? Since I'm getting ready to flush mine, and you've done so much research, I think I'll just go with whatever you recommend. Your water pump life is a strong advertisement...

I've used Prestone Orange in the past.

Heath

valvolines zerex brand claims to have low silicates, but none actually state zero silicates. zerex also offers to interesting cleaners, a Super Flush and a Super Cleaner. I think they're the same thing. Super Cleaner says it gets whatever the flush doesn't...whatever . I think at this point I'm more interested in getting everything cleaned out as good as possible in the radiator and in the motor and make sure those heater coils are free flowing for the winter. I'll try a couple rounds of the flush or maybe the cleaner while I'm doing this. I've never done a good flush other then with tap water(uneducated at the time) and it's about time. I'll look into replacing all external coolant hoses to.

Good idea to check the thermostat say a year after flushes as many don't flush the chemical flush [Zerex/Prestone] out completely. Have seen the thermostats eaten away. Heck I even did it to mine ONCE!

Why regardless of the AF I use, one year is enough especially with my running 25% Summer and 50% winter.Chemical flushes should be limited to every 2-3 years but drain and fills annually is really cheap -- do it yourself.

Hey Fred, the reason we've been given for the 50/50 coolant to water is to stop cavitation.Apparently the Ethyl Glycol smoothes out the Bubbles, so to speak, as the air bubbles will also eat away alloy when they are traped & is called Cavitation. (particularly prevelant in Hard Water)

A good example of this is the Toyota Diesel with the 2l & 3l motor. Remove just about any water pump from them & you'll see pretty good cavitation.

Chally,

I also add redline wetter water, that takes care of cavitation, pretty well.

Many racers that dont care about long term additives go with superthin mixes (90% water rest AF etc).Or only water and redline wetter water.

So I feel pretty safe with a thinner mix when I am running rWW.

Fred...

Cavitation wear shows up inside the water pump housing and the Nissan V8 never have a problem in this area due to the design.The number one problem is water pump seal failure caused by silicate additives.....removed/replaced my 169k [2nd unit as 1st pump leaked at 66k] in June looked brand new inside no visable cavitation or any other wear.....just preventative maintenance as I was changing all the other metal [thermo,thermo cover, and anode] and large rubber hoses.As the custom rad has only 78k [4 years] hopefully it will last another 6.