hi just curious on how to do a coolant flush for a 3.5l tj magna

1. Drain the radiator (there's a small plastic tap to open up)
2. Drain the cylinder block (there's a drain plug on both the front and rear bank - access is from underneath)
3. Remove and empty overflow bottle.
4. Run tap water into the radiator cap opening and wait until clean water comes out the engine block drain holes.
5. Replace drain plugs (use some locktight) and overflow bottle and close radiator tap.
6. Refill with a mix of anti freeze / anti boil, diluted to 33% - 50% with distilled water.

What he said. . . . and repeat 3 years later.

what do the engine block drain plugs look like?

14mm bolt heads

Here are a few other things I've been pondering over:
Does the above mentioned method drain the heater as well? Also is the initial coolant added thru the radiator cap or the overflow bottle (like Falcons) and finally, do you need to bleed the system of air once it is full. Thanks.

just make sure the engine is cold when you go runing cold water into it, dont want to chance cracking your block. hot and cold just dont go together. also id suggest using a decent coolant like nulon ( personally i think nulon is great, others will disagree) no use putting cheap crap in to save a measly 5 dollars. while your there id also suggest checking your coolant hoses for any leaks, fray, or if they seem overly soft so you can change them if needed while the fluids are drained and save making a mess

mostly your coolant will be added from the radiator cap, the reason ive seen with most falcons they are added through the overflow bottle is because most falcons dont actually have a radiator cap ( from what i have seen) no idea on bleeding with the 3rd gens but id be intererested to know that, i would think not

Falcon's "bubbly" overflow tank is pressurised... best not to fill it too full (oops!)
as the overflow's outlet seems to point straight at the 4.0's sparkplug area.


When flushing best to switch your heater's (nonCC) temp knob to max High, it'll get the coolant thru faster.

Old coolant shouldn't be yellow rusty; if it is i always like to do a doubleflush. Flush until clear
then close all outlets and fill with plain water. Run engine until warmed, then let cool.
Drain system then only refill with proper coolant mix.

Make sure you know difference between Ready/PreMix vs Concentrate. :)