I'm in the process of changing the coolant in my XJ (4.0). My question is, is there a drain on the block to get most, if not all of the coolant and flush out of system before I put the new coolant in?

 

Yes, there is one.....But I'm unsure of its location though.....

 

I'm not so sure there is. Maybe a plug? Anyway, the E-Fan comes out with two little screws, and then remove the lower hose is what I'd do. The "water jacket" around the cyl's is up high. Draining 95% is good enough for me.

 

There is but most likely wont get it out just drop bottom hose good enough as stated above.

 

I've searched around when I changed out my coolant a lot of people said they used the drain on the block but never really said where it was...... I ended up just pulling off my lower radiator hose instead of fooling with the petcock. Worked great too. But the fact remains though ALOT of people swear they pulled the lower hose and the block drain..... I'm interested cause I
wouldn't mind to run some water through my block to flush out some of the crap that's collected over the years.
Djb where are you lol. I bet he knows.

 

There is a coolant drain plug on the driver side of the block. I don't have a picture of it so I can't show you exactly where it is. But it's the only thing there that looks like a drain plug

 

Drain plug should be almost directly under the exhaust port on cylinder #5

 

There are plugs on the driver's side of the block. They're not all that low anyway and they are 5/16" square drive. They're a bear to get out with the engine setting on a stand in my garage. I sure wouldn't want to try removing one with the engine still in the vehicle and the exhaust manifold in the way.

 

 

Done, yeah, I found the block drain(s). I didnt want to even try to remove, besides, removing the lower radiator hose seems to be the lowest point on the block anyway. I flushed the system and found alot of grime/fine shavings in the system. I replaced the heater hoses minus the heater valve then filled the system (50/50 solution). In an attempt to get most/all of the air out, I slowly filled it thru the top radiator hose and left the top heater hose off at the water neck on the engine. The radiator filled, forcing coolant up thru bottom of the block meanwhile I heard gurggling/burping coming thru the top heater hose till it was full. I drove the jeep all day yesterday, everything seemed good and never had to top off the system.

 

And the crowd Cheers! You gotr' done, good job.

Shavings? Bright, not rusty crap? MMMM. We need one of those lights like Batman has, but with DJB!

I once had a Toyota where the water pump bearing went to S*ough, but still the seal didn't leak. If I had the belt loose on that for some reason I might feel for play in the pump bearing. Brown crap is normal/expected