Help! Coolant doesn’t get into engine block during flush

Started a flush on my 2004 prerunner 2.7L by draining the radiator but when I opened the engine block coolant drain plug nothing came out. I had just swapped an Engine Coolant Temp sensor and figured it must’ve drained when I removed it.

However, I started filling it up with distilled water and only got about 1.25 gallons before it was full. Water came out Radiator drain but still not coming out of the engine block drain. Removed thermostat and tried it again but still nothing coming out of engine block.

Any ideas what is preventing fluid to enter engine block? Could it be some air trap when I removed the engine coolant temp sensor?

Any help appreciated!

 

Welcome!
I have yet to do this job myself, but how are you adding the water? I think it has been recommend to disconnect the upper hose and add through it to fill the block.
Maybe someone more experienced can chime in

 

Hello!

I´m following this guide i found

https://www.tacomaworld.com/threads/coolant-flush-1st-gen-tacoma-beginners-guide.425479/

Adding water through the radiator but can’t get any fluid coming out of the engine block drain plug

 

You might try removing the plug completely from the end of the drain fitting on the side of the block. If you still don't get any outflow, I would poke around in there (gently) with a long screwdriver.
Good luck.

 

did you run the engine up to operating temp after refilling with water

 

Might be rust or crud in the plug depending on how maintenance was kept up with on the truck. Or could have an air bubble or ai lock. When you have the eninge drain open is the radiator cap also off.
Maybe somebody put stop leak in it before. I've replaced freeze plugs in engines before that had stop leak added and they had a ton of sludge and stuff in the water jacket

 

Hey everyone, thanks a lot for the help. You guys were right and it was just a bunch of rust build up since the truck hand´t been maintained very well.

Took DGXR advise and poked at it with a thin sharp metal file and its finally draining!

 

glad you got it worked out, hardest part is getting to that petcock in order to open it