Could someone PLEASE give me the TRUE instructions on how to change / flush coolant?

[importrev]

At least for a 2002 Nissan sentra. I hear different directions everywhere !!!! :) I'd like to thank anyone in advance !

Heres what I think I should do.

1) Drain coolant
2) Fill with distilled water and maybe coolant flush
3) Run engine with water / flush

Now here is the confusing part that i can never find the answer to...Do I close or leave the radiator cap open? When I leave it open, the water comes out almost immediately before the engine even has a chance to heat up...but if i close it, it feels as though I'm running half the engine with no water at all because me filling the radiator isnt going to bring water up and INTO the block, not to mention the system has air in it.

So I'm always very edgy when it comes to running the block after filling it back up with water....the last time I did it, i ended up not flushing, just drain / refill.

Now when it comes to burping the system, I cant remember what happened last time ( a year ago) I did it but i left the radiator cap open and started the engine. Didnt do anything with the heater and I cant remember if the Tstat opened up or not but i ran it for as long as I could before the water came up and flowed out of the radiator. Air came out and i remmeber squeezing a hot upper radiator hose.

What am I doing wrong (if any)? thank you so much

[JudoJohn]

I ran into the problem a couple of years ago. Here is what i do: when you have the old coolant out, or drained as much as you can, add new coolant (I like a 50/50 water coolant mixture) to the radiator.when it seems as if it is full, wait a bit. it will go down a little. fill up the overflow tank with coolant. run the engine up to operating temperature. Park car. let cool down. when the engine is cool, it will take more coolant in the radiator. before the level is up to the top of the fill neck, squeeze the hoses to get air bubbles up and out. Fill up to top of radiator. put cap back on. check every day for the next few days the same way (always cold).

I had the same thing happen with it overflowing when you start the engine and it begins to warm up. That is why i use the method described above.

[importrev]

Originally Posted by JudoJohn

I ran into the problem a couple of years ago. Here is what i do: when you have the old coolant out, or drained as much as you can, add new coolant (I like a 50/50 water coolant mixture) to the radiator.when it seems as if it is full, wait a bit. it will go down a little. fill up the overflow tank with coolant. run the engine up to operating temperature. Park car. let cool down. when the engine is cool, it will take more coolant in the radiator. before the level is up to the top of the fill neck, squeeze the hoses to get air bubbles up and out. Fill up to top of radiator. put cap back on. check every day for the next few days the same way (always cold).

I had the same thing happen with it overflowing when you start the engine and it begins to warm up. That is why i use the method described above.

so it is safe to run the car with cap on, reaching operating temperature before any burping is done ?

[JudoJohn]

Yes, it is. just watch your temp guage.

[popkr]

I have had success with draining ,then close radiator petcock leave radiator cap off ,pulling the lower radiator hose . carefully , or you may have to replace..... stick slow water hose in bootom of hose start engine . As temp comes up thermosat will open and start pulling water you are now back flushing your whole system including the all important heater coil then drain as completly as you can even unhooking your heater hoses to the fire wall and blowing out. Reinstall hoses with a little great white pipe grease if needed. Refill with 1/2 distilled water and 1/2 orange or green juice keep checking till air pockets are gone. If you using the good coolant you are good for three years.