Postby smj999smj » Wed Nov 08, 2017 10:12 pm
Yes, he means the two caps with the orange stickers on them. This system is similar to what European cars have used for years. The cap on the coolant reservoir is the actual pressure cap of the system; the one on top of the radiator is simply there for filling during servicing.
Nissan used long-life, green coolant for many years and then started phasing in Nissan blue ("longer-life") coolant around 2010 in various Nissan models. Both coolants are made by Pentosin; Pentosin Pentafrost A2 is the green, concentrated anti-freeze that needs to be mixed 50/50 with distilled water. It is good for 90,000 miles initially, but should then be replaced every 60,000 miles afterwards. Pentosin A3 is the blue coolant and only comes pre-mixed (meaning no need to add water). It is good for 135,000 miles. Both are cross-compatible, but one has to remember that any green coolant mixed into the blue coolant will diminish the 135,000 miles service life of the blue coolant to some extent. My preference is to just keep the green with those with factory-green fill and blue with those that have the factory blue-fill. Both are excellent coolants. Of course, genuine Nissan coolant is available from any Nissan/Infiniti dealer. Pentosin coolant is available from a number of sources, including on Ebay, from Rockauto.com and even some parts stores. It's not cheap, but nothing ever is, right?
"Works with all color coolants" like Prestone and SuperTech (Walmart) will work fine in the VQ40DE. Just make sure if you use a concentrated anti-freeze that you stick with distilled or de-mineralized water when mixing it and NOT tap water or well water! I get distilled water from Walmart for under $1/gallon. Personally, I've always like the genuine Nissan coolant going back to my Nissan tech roots; these days, I keep at least a gallon of Pentosin A2 green at the house.
When I do servicing of the coolant, I first turn the key "on" and turn the front and rear heaters "on" and to the hottest settings. Any time I drain the coolant, I almost always end up with a perfect 2-gallons. I catch the coolant in a pan and will then pour it into old, 1-gallon containers so I know how much I drained out of the system. I'll jack up the front end as much as safely possible and, with both caps removed, start pouring the new coolant into the system. I'll usually get about 1-3/4 quarts in when the radiator is full and the reservoir is around 1/2 full. I'll install the radiator cap and start the engine. I'll fix a tool or rod between the gas pedal and the seat to keep the engine running around 2500-3000 RPM. I'll let it run a few minutes, topping off the reservoir as needed and until hot air is coming out of the heater vents. Then, I'll install the reservoir cap and shut the engine off, then lower the vehicle. Seems to work every time.