The additive packages in antifreeze are supposed to prevent that.

 

I had to replace a heater core back in the 70's in my 70 Mustang because I was mixing anti-freeze with tap water and the very small passages in the heater core plugged up. Maybe the coolant of today will prevent that, but distilled water is cheap and I learned the hard way.

 

Filling with distilled or deionized is a good idea, but flushing with tap should be okay. I suppose it depends on exactly how good or nasty your tap water is.

 

Flushing with tap will be okay if you can remove the block drain plugs to drain the entire system. If you don't remove the block drain plugs, half the system will be filled with tap water.

 

You can't on the 98 blocks - not sure about the others. The only have one on the drivers side. I wire wheeled the entire block, just one plug, that's it.

It sucks flushing it - Specially if you have the manifold removed.

 

Hey guys, i got just about all of my dash back in from replacing the heater core. What are some quick steps on filling back up my coolant? Im already drained out and sitting empty . i am not using any water, im using a 50/50 mix.
correct me if i am wrong

1) fill the degas/resevoir coolant tank untill the cold line is met.
2)start the truck with the tank lid on or off?
3) Let the truck reach its temperature
4) refill again to the max mark

 

I gave yuh the manufactures write up. You have temp1's write up - he knows what he's doing. Not sure there's much more to it.

Air in the heater core is the problem you can get, I got air in mine right now lol - I have to fix that. - New shop , still organizing

I would fill it according to the manual, then if you have any problems - like the one I have now, just ask. I'm going to have to pull the top heater core hose on this one. - It's been bled 3 times already.

 

I have a 1998 F150, 4.2L V6 manual transmission that needs to have the coolant changed.
When locating the engine drain plug, mine does not look like the one in the Pic that Temp1 posted in another post. I'm attaching the pic of what I suspect may be my engine's coolant drain plug.
I wonder if anyone can confirm this for me. I hate to loosen this and get a nasty surpirse.
Thank you in advance for your input

 

Hey Scott, when i did my 99, They called for a hex allan key head style? that made me look for an hour. The actual bolt was identical to the one you are referring to, it is the same on my 99. The only difference was, i had a wire with an Orange end that plugged into the engine block right beside my plug.

 

Thanks you for your reply.

Yesterday, I got tired of looking for the drain bolt, and called the dealer to get some info. Didn't get much info in terms of DIY, but they did say they don't drain the engine block when doing engine coolant change, only the radiator is drained. So, I thought for all that they charge, I can easily drain the radiator and top the reservoir back again myself, w/o worrying about draining the engine block. If it's good enough for them, why shouldn't it be good enough for me. I know it's not the same as doing the job 100 pct correctly, but if this is all the dealer is going do..... and perhaps some good is better than none????


Any thoughts on this?

 

I alway just vacuum it out..