2nd gen coolant drain on motor

[jacksonh18]

I got a prestone flushnfill kit and wanted to hook up the system to get everything out of my system before changing my radiator (I have transmission fluid in my coolant).

I watched this video https://www.youtube.com/watch?v=WOu_Si3gdbs

The mechanic said there is a radiator drain plug on the radiator, but also a drain plug on the motor. I suppose I could just drain the radiator, add water run it with the heater on and then drain it, but I'm thinking the flushnfil system is the way to get everything out before changing the radiator.

Anyone know where the drain plug is?

 

[koda2000]

i don't think there is a drain on the engine, only the radiator.

 

[SoHK_alumni]

I know on the 5.0 there are some plugs in the block just above the oil pan that open to the the cooling system. Your 4.0 might be similar.

 

[lobo411]

There's no drain plug, and I wouldn't mess around with the hoses any more than absolutely necessary (I would certainly not splice in a backflush fitting...just BEGGING for a leak later on). To flush, I just drain the rad using the petcock (the bottom radiator drain plug), refill with tap water, run the engine for a little bit to circulate things, and then drain. Repeat 5 times, till the water comes out more or less clear. Then refill with distilled water, and repeat the above process 5 times. After the last drain, refill with straight antifreeze. Since half of the water stays in the block every time you drain, you end up with a 50/50 mix.

 

[gdgiordano]

Is there a way to get the mixture higher? Obviously the water needs to come out of the block.

 

[TekMan05]

There's no drain plug, and I wouldn't mess around with the hoses any more than absolutely necessary (I would certainly not splice in a backflush fitting...just BEGGING for a leak later on). To flush, I just drain the rad using the petcock (the bottom radiator drain plug), refill with tap water, run the engine for a little bit to circulate things, and then drain. Repeat 5 times, till the water comes out more or less clear. Then refill with distilled water, and repeat the above process 5 times. After the last drain, refill with straight antifreeze. Since half of the water stays in the block every time you drain, you end up with a 50/50 mix.

But will the system properly mix the water and anti-freeze together? I guess you could always test that with one of those coolant testers??

 

[lobo411]

But will the system properly mix the water and anti-freeze together? I guess you could always test that with one of those coolant testers??

Sure...while you're doing the flushing/mixing, turn on the heater so the heater valve opens and you exchange the contents of the heater core too.

 

[colintrax]

There's no drain plug, and I wouldn't mess around with the hoses any more than absolutely necessary (I would certainly not splice in a backflush fitting...just BEGGING for a leak later on). To flush, I just drain the rad using the petcock (the bottom radiator drain plug), refill with tap water, run the engine for a little bit to circulate things, and then drain. Repeat 5 times, till the water comes out more or less clear. Then refill with distilled water, and repeat the above process 5 times. After the last drain, refill with straight antifreeze. Since half of the water stays in the block every time you drain, you end up with a 50/50 mix.

For what it's worth I have a black flush fitting on mine. Been there a few years now and no leaks. It's on the back side of the heater though so if it does leak I just need to turn the heater off

 

[lobo411]

For what it's worth I have a black flush fitting on mine. Been there a few years now and no leaks. It's on the back side of the heater though so if it does leak I just need to turn the heater off

Ya it's definitely your mileage may vary. I removed my engine side heater hose to valve lines when I did my head gaskets, and it was a royal pain to get them to stop leaking. I put in new hoses thinking the old ones just lost their spring, but I ended up having to use screw clamps w/ hex heads, and then I had to tighten them with a socket/ratchet to stop the leaks.

Maybe if my system was really dirty I'd try backflushing, but mine's pretty clean and only has 163k on it.