What Coolant do you use?

[RustyBucket]

Since I have to remove some coolant hoses under the plenum to get at my knock sensors, it looks like the perfect excuse to change out the coolant. Not all coolants are the same and I've read about how some coolant types are bad for aluminum engines, so I am putting the question out to NICO's Q45 owners:

What coolant do you use/recommend?

[Poyzinous]

Nissan's coolant. The Green type. Its specific to be perfect for Nissan vehicles. But it needs to be mixed with water, since its concentrated

[Q45tech]

Almost all coolants contain the same ethylene glychol. The question is what are suitable additives for all aluminum vs mixed or all iron engines.

"The green in most Japanese cars contains no silicates, so it's not the same as the green in the parts store"

What ever you use test the ph annually and replenish additives.

Some tap water has excess minerals and anti sluding chemicals, clarifiers, etc so distilled or deionized water is the best mixer to sweek out longer life.

I usually drain rad every year and readd ~4 quarts of new mixture along with removing and washing out grim in overflow tank.

[Infinitiguy19]

http://docs.google.com/Doc?docid=0AZVDQ ... NWZ6&hl=en
http://docs.google.com/Doc?docid=0AZVDQ ... Njeg&hl=en
http://docs.google.com/fileview?id=0B5V ... YWM1&hl=en
http://docs.google.com/fileview?id=0B5V ... ZGE1&hl=en
http://docs.google.com/fileview?id=0B5V ... ZGE1&hl=en

COOLING SYSTEM
Antifreeze
http://www.motor.com/MAGAZINE/Articles/081999_11.html a short excerpt the whole is well worth What kinds of coolants are out
there? Aside from the limited sale of propylene glycol to environmentalists, it's ethylene glycol... about 93% ethylene glycol, that is,
plus water and specific rust and corrosion inhibitors. Here's a rundown: Conventional American coolant (green or gold) contains
silicates (a long-used aluminum corrosion inhibitor) and other inhibitors. Silicates work quickly to protect aluminum, but also are
depleted relatively quickly in service. They're also somewhat abrasive (being based on silicon-sand), so they've been implicated in
water pump seal wear. Advocates say tests show silicates last longer than was commonly believed. And with the latest seal materials,
they actually do a better job of protecting the water pump, because they both resist cavitation erosion-corrosion and "repair" any that
occurs. OAT coolant (orange or pink) contains no silicates and no phosphates. It's a blend of two or more organic acids, a specific
class of inhibitors with slow-acting, long-life properties. Texaco's Havoline Dextron-Cool (also sold under the Goodwrench label by
GM) was the first example. Prestone and Peak also have introduced OAT coolants that are chemically compatible with Dextron-Cool.
Conventional Japanese coolant (green or red) contains no silicates, but has a heavy dose of
phosphates and other inhibitors, including a modest amount of one or two organic acids.
Conventional European coolant (blue or yellow) contains a low dose of silicates and no
phosphates, but does include other inhibitors, including one organic acid.
Hybrid European coolant (blue or green) is similar to conventional European, but with a much greater dose of organic acids. It's a
balanced formula designed to have the silicates provide the primary protection for the aluminum, then allow the organic acids to
provide long-term protection.
Hybrid American coolant (green or orange) contains a moderate dose of silicates, plus a blend of organic acids.
2897 Now all Infiniti have aluminum heads and radiators plus either a Iron or an Aluminum block depending on the model. When an
engine is composed of different materials corrosion is more of a problem but all aluminum is not the same since different alloys
[95%aluminum 5% other metals] are used in different places. All antifreeze contains additives to prevent this corrosion which get used
up with time. Some last 15,000 miles some last 50,000 miles depending on the product and the water that is used to dilute them and
engine/radiator construction. Tap water varies by location as to hardness and what chemicals are added to make it clear and safe
looking, spring water may be much worse but looks good. Real distilled water contains nothing but water hopefully! In the Q a metal
pipe located on the driver’s side engine front between two radiator hoses is the designed in weak link. It corrodes first inside telling
you you’re not doing something right. When ever the lower radiator hose is changed look inside this pipe for corrosion. Anyone who
has replaced the original fill distilled water with any amount of tap water will have some plus any Antifreeze that has not been
changed every 30,000 miles will have some. Most of you will have a lot showing the need for remedial action or a radiator - water
pump is in your future. Please don't believe the hype about coolant lasting forever again just enough to get through the warranty is fine
with Nissan otherwise the replacement radiator people would be out of work. Ask your shop if they use distilled water or just tap
water. If they don't bring them 2.5 gallons ($2.50) and make them use it. It's not a cure for bad practices but it's a start. Previous posts
have discussed the different additives in Red/Orange/Green Antifreeze and which you should use for which engine type to maximize
component life.
3424 Remember that the thermostat just begins to open at 174F and is fully open at 195F, when 70F outside the water flowing into the
radiator should be about 190F but on the outlet side it should be 170F or less on a Q there is a 195F thermoswitch which should turn
on auxiliary fan at this temp. It is not unusual for a Q to provide 210F radiator inlet water in summer with AC on. As I have said a
hundred times the in radiator AT cooler is a heater to warm up AT fluid to at least 175F when it's 20F outside. If it's 90F outside and
220F in radiator that will be the temp of ATF flow back to AT which will easily heat the ATF to 250F. Even my external cooler only
system heats Mobil 1 ATF to 200F [pan temp]in hottest summer. The worst case is a slow [1700 rpm = 50mph] 4th gear up hill pull
with AC on at 100F. [use 3rd to decrease temp]. This is why ATF gets fried in Summer. Two methods new in Spring or get bad out in
Fall or both. Any temp over 240F has already warped metal seals even 20 minutes worth.
Prestone cooling flush is excellent and I use it often in my car, at the shop we use BG Flush. You can leave the Prestone in all day and
flush in afternoon as long as the radiator doesn't get cold as the dissolved minerals will precipitate out in cold water. Always used
distilled water as the final 50/50 mix with AF [orange red green extended life type].
Q45Tech