hey guys,

I'm going to change the coolant in my 04Z. I've read some of the posts regarding this but I still have some questions. From what I've read it seems straight forward.

1. Remove plastic cover under engine
2. When engine is cool, remove radiator cap
3. Remove radiator drain plug on driver's side of radiator, let drain
4. To remove more coolant from system, remove bleeder plug near rear passenger side and let coolant drain.
5. Install radiator drain plug and slowly (very slowly) fill radiator until full
6. Also fill coolant slowly (very slowly) where bleeder plug is located until full
7. Put radiator cap and bleeder plug back on and start engine, set heater to max, and slowly bleed air from bleeder plug, refill radiator when cool (repeat this procedure a bunch of times)

My questions are, has anybody ever just removed radiator cap and radiator drain plug and allowed coolant to drain. Then start car and keep adding distilled water to the radiator. After a while (20 to 30 minutes) you should have gotten rid of all the old coolant and have nothing but distilled water in system, then just add a gallon of coolant at the end. I did this in my Mustang before, I'm not sure if it will work on a Z.

Also, from step 7 above, if you leave the radiator cap off while starting car to help bleed air from the system. Will coolant spill out the radiator cap opening when the thermostat opens? I want to avoid that mess.

Any help would be appreciated. Thanks.

 

I do the same but drain twice. Before the second drain allow the car to run with the heater on.

 

Here's my method and it works like a charm.

First, put the car up on Rhino Ramps in the front. This makes the rad cap a high point in the system and gets more air out. Remove rad cap, rear bleed screw, and drain the coolant.

After you put the drain plug in, start to fill the rad with your mixture of coolant and distilled water. When its full, start squeezing the radiator hoses. This will burp the system and should give you some more room to add more coolant.

Now, this next step is the most important. Buy a very small funnel that has a small enough tip to fit in the rear heater hose where the bleeder is located. Replace the radiator cap and start adding coolant to this hose via the small funnel.

When full, replace the bleeder screw and run the car for a bit. Do a couple laps around the block to get up to full temp. Run the heater full blast. Don't be surprized if you don't get hot air yet.

Park the car and let it FULLY COOL for several hours. Open up the bleeder screw and use the small funnel again to add more coolant. As you add it, squeeze the upper rad hose to burp more air.

It took me 3 cycles of doing this, and each time, I could pour in another 8oz or so of coolant mix. Its worth it though as I got every bit of air out of the system.

 

If you leave the cap off,start the engine==you'll get a mess.