Heeelp! I just installed a fresh 4.2 engine in the 2000 Econoline,
I found it nearly imposible to get the coolant to flow correctly to
properly cool the engine. After disconnecting the heater core & letting coolant
out, it started to circulate & the vans heater was working fine. Everything seemed normal, & cooling properly, or so I thought......

Well, I went for a drive, & after about 3 miles, it happened again, unfortunatly I never realized it. The coolant stopped flowing throught the heads & the heater was blowing cold air. Temp gage was in the "normal" range. By the time I realized this, It was already overheated. The engine was pinging from the excessive heat, I pulled over & shut it down. I just hope I wasn't too late.

So now I ask, how in the world to I get this cooling system working properly?
I am very frustrated with this thing.

 

Don't you just love the engineers that invented these "hard-to-get-the-air-out-engines"?
One of the best tools to use on these engines is a purger that hooks to your radiator cap. It actually pulls a vacuum on the system and pulls the air out of the cooling system and at the same time adds coolant. If you don't have one of these you need to beg, borrow or steal one. I believe in them that much.
You obviously had an air bubble in your coolant and as it heated up, so did the volume of the air. In cases like this you need to be more patient before giving the car a road test. Turn the car's heating system on, vary the rpms and always watch the coolant level. (If the radiator cap is on the radiator and not on the coolant recovery tank, that is)
The process for one car may not work for another.

 

Well, I towed it home & found the problem. It appears I did have the air out the first time. It appears I lost a freeze plug on the block. What up with that? So, all the coolant came out so fast I never had a chance. The temp gage never went up I suppose because there was no coolant to give a reading. I am not sure when the coolant dumped because I had no symptoms while driving down the road. My first symptom was cylender detonation, & I shut it down after two blocks of this. Might have been too late?

I will talk to the machine shop monday. But I am sure they won't stand behine any damage, if there is some. Not sure how hot these engines can get before there is damage. Pretty upsetting seeing I only have 7 miles on it. I have never had a freeze plug just pop out.

any thoughts?

 

hi 68ragtop you have really been put thru the mill, just wishing you well and hope m/c shop treat you right. bokker.

 

Thanks for the kind words. I really doubt they would do much seeing I did the assembly. But I have never seen a freeze plug just pop out like that. I am not a profesionaly engine builder, just a hobbiest. So, they might use that against me. I just hope it didn't get too hot.

They installed those temp sensing freeze plugs in the heads. The ones with the epoxied washer & a lead type center. Well, the center melted out. Not sure what they are for, other than a type of detection of an overheat situation.

All I can do is install a new plug (if I can get to it) & see if I have any problems.