overZealous

What you need:
- (1) Gallon Genuine Nissan Anti-Freeze or Equivalent (*1)
- (1) Gallon Distilled Water (*1)
- (2) O-rings for drain and purge plugs
- Phillips Screw Driver
- 10mm Socket
- Container to Drain Spent Coolant
- A garden hose also comes in real handy.

(*1) More fluid may be neccessary if you are doing a total system drain.

Warnings:

- Obviously you are NOT going to do this when the motor is hot or even warm for that matter.

- If your vehicle is not completely cold use a rag to cover the radiator cap and turn it counter-clockwise 1/4 turn to bleed off any pressure. Then remove it.

- Do not let coolant contact the drive belts


Position your vehicle as appropriate. I did not jack mine up. In fact, I pointed the front end slightly down-hill so I could get as much coolant out as possible. If you want to jack up the front end a bit I suppose it does not make a whole lot of difference. If you plan on removing the engine block drain plugs, which there are three (3), then you'll definitely need to jack it up so you can get underneath the car.



Next you'll need to remove our friend, the underengine cover using a 10mm wrench.









Remove the radiator drain plug and radiator cap (if you have not already done so) and drain the old coolant. The drain plug is on the bottom of the radiator on the driver's side of the car as shown. Use a phillips screw driver to remove the plug. Expect to get around two (2) gallons of coolant out so size your drain container appropriately. There are also three engine block drain plugs but there is no reason to remove them for a routine coolant change IMHO. I did not and still got 8 quarts out of 9 1/4 out of the system.







Next remove the reservoir tank, drain it and clean it. The tank is held in place by a single 10mm bolt. Remove the clamp from the reservoir hose at the radiator filler flange and pull off the hose. If you prefer, you can disconnect the hose at the tank end.











Replace the reservoir tank and the radiator drain plug. The factory manual suggests replacing the O-ring on the drain plug. I did not and did not have a problem. Since I did not remove ALL of the coolant from the system I pre-mixed the anti-freeze and distilled water before adding coolant. I used a 1:1 anti-freeze to water ratio although you can use up to a 70% mix. Before adding coolant, remove the purge plug from the heater hose which is located on the passenger side of the vehicle up near the firewall. This plug is identical to the radiator drain plug.

Refill the reservoir tank to the "MAX" level. Add coolant directly to the radiator slowly to allow the air to purge itself. The Factory Manual says to add coolant until coolant comes out of the heater hose purge plug. It also states that if the radiator fills up and no coolant comes out of the purge plug to replace the radiator cap and squeeze and hold the upper radiator hose and replace the vent cap. Then, with the vent cap and radiator cap installed, warm up the engine to normal operating temperature. Run engine to 3,000 RPM for ten seconds repeating several times. Let it cool down, recheck coolant level and repeat until the level stops dropping. Reattach the underengine cover.

Ok, thats what the manual says. Here's how I did it. In my case I did not get any fluid out of the purge cap. It appeared to me to be several inches higher than the top of the radiator. I filled the reservoir tank to the max level. Next I filled the radiator to the top. I then used a small funnel and added coolant in directly through the purge cap until it was full. I ran the car for a few minutes with the heater on high, let it cool down and rechecked the coolant level which was fine. However you do it just make sure you get a complete fill and have purged all of the air out of the system. Run it for bit, let it cool down and recheck until it's right. You may have to play around with it a bit as I did. It's not difficult. Doing these stupid DYI posts require much more effort than the actual work. Happy maintenance.

yobri

iTrader: (2)

Nice pictorial you got there. I'm now subscribed for when I need to change my coolant as well. Thanks

overZealous

By way of follow-up to the original post I would have to say that bleeding the air out of this system is a bear. The 350Z has more plumbing than a nuclear powered aircraft carrier. I checked it again this morning and it still had alot of air in it. I could tell by squeezing the upper radiator radiator hose (with the cap on). First I tried to add more coolant throgh the vent hole in the heater hose but that didn't work. I then tried doing it as the manual said but that didn't work at all. I finally just drove the car around a bit let it cool down and the level in reservoir did finally drop about an inch(indicated air had been purged). Sorry it was a first for me and I still haven't worked out the kinks. I also did not cover flushing the system or draining the block so I've included some additional images that describe the process a whole lot better than I can.

pargion

thanks for the tutorial!

by the way, how necessary is it to flush the cooling system before adding the new coolant/water?

overZealous

The FM (see above) states that you should flush the system if you detect contaminants, rust, corrosion, etc. in the discharge. I'm not sure if it should be flushed or not but I would venture to guess that if you had a dealer do it at the 30K service they would not. Mine only has 15K on it. For some reason I thought the service interval for that was 15 but when I logged the repair in my owner's manual this morning I saw that it was 30K. Pretty silly that I am changing the coolant out at 15K considering mine is scheduled for it's final repair attempt on the suspension and the transmission a week from tomorrow. I still have to maintain it. Also keep in mind that if you do flush the system with water you will definitely want to remove those engine block drain plugs to get all of the water out unless you a) use distilled or demineralized water for the flush and b) measure exactly how much water you get back out when you drain it. Otherwise it will be difficult to get the correct anti-freeze to water ratio.

mode101

Thanks for the great post, and nice clear pics!

johnsZ

you might want to add a pint of engine kool or similar stuff- like water wetter. it is a surfactant that reduces the surface tension, and at least in a couple cars with temperature gauges, I have seen a noticable reduction in the operating temperature maybe 5 or 10 degrees- not huge, but for 4 or 5 dollars, not a bad deal.

350ed

iTrader: (17)

No pics... what happened?
www.350zbuyersguide.com/ dead?

LaoSiFu

iTrader: (97)

Argh I finally decided to change my coolant and all the pics are showing "X"s.