Got a big radiator problem...

[Przybysz]

Ok so I had intended to replace the thermostat today, but i noticed that all inside the tubes and in the coolant tank were rusty... I didnt have the time to do a full radiator flush, so I just improvised. I just cleaned the coolant tank and I put the thing all back together. Before I started it, I dumped a half bottle of coolant into the radiator itself, and put some more into the reserve. I intended that all I would have to do was bleed the excess air and then top it off. But when i let my explorer run for a while it just started spraying out of the radiator cap and would not stop. I think it dumped all I put into it and then some. But the coolant tank is still half full?

Where do i go from here? I filled up the radiator again with water to start, but idk what I'm doing so maybe i'll have to drain that...

 

[Przybysz]

Here are some pictures of whats happening.

I kept the cap off because well... You can obviously see that that kind of pressure is not going to be held in by the silly little cap.

Do you think I may have a busted water pump??

 

[92exp4x4]

Coolant will flow out while the engine when it is running because of the waterpump. Did you completly drain everything? Rad, engine block, etc.? Did you get a thermostat with the little by-pass hole? This makes it a little easier. Drain the system completely and fill with new 50/50 mix coolant. You can buy it mixed or do it yourself. Get the concentrate, you get alot more for the money.

I like to jack the front of the truck up as far as i can to make the rad cap the obvious highest point, then add coolant until i cannot put any more in. This will take some time as it will slowly burp. Then start and run the engine with the heater on until the thermostat opens. It will spew fluid out for a while then all of a sudden it will draw the level down quickly. This is the thermosat opening. Quickly top off the system (Carfully, as fluid will be hot now) and cap the rad. This should get a majority of the air out of the system. Fill the resevoir up about 3/4 its capacity and drive the truck. Take extra coolant and a large towl with you. If you did it correctly the extra coolant in the res will be drawn into the system.

You can uncap a hot radiator, but be very careful. This is where the towl comes in. Drape it over the cap and slowly loosen it to its first stop. Let the pressure bleed off if there is any, then you can check/add coolant.

 

[Przybysz]

So youre saying that it will spew liquid out the cap for a while and then go? Because I'm going to do that with all water tomorrow to see if that works. But when I tried with the coolant/water today, it spewed out like 50% of what was in the radiator, and when I opened it more it just exploded with coolant everywhere

 

[Anime]

Are you sure you installed the new thermostat in the correct direction? Usually the system only builds up pressure to blow out fluid when the 'stat is stuck closed...or installed backwards.

Once it's in there good, just do the flush like you were going to, or just change the coolant a few times over the next few weeks/months.

 

[Przybysz]

Yeah thermostat is in correctly. I'm thinking something is plugged. Cuz with that radiator cap on the water and coolant sprayed out everywhere for like 5 mins straight.

I'll be taking it apart soon. Hopefully tomorrow.

 

[92exp4x4]

Woah, if its that bad something else is going on. Did your truck overheat before you started this project? Could the engine be pressurizing the cooling system through a bad cylinder head gasket if it did overheat?

Just some ideas. although not pleasent

 

[Przybysz]

Yeah it overheated but it did not spew out coolant like this. And it does have a blown headgasket, but I doubt if thats the main problem. Should the bottom return hose to the radiator be really hot? because it was quite cool after it had been running. maybe thats plugged?

 

[Anime]

There's usually no other restriction in the system other than the thermostat. Either the new thermostat is faulty (it happens, they say you should check to see if it opens in a pot of hot water on the stove before installing to be sure), or there is some debris elsewhere in the system causing a bottleneck, and the pressure that makes the coolant spray out.

I say new thermostat, take the old one back and get a replacement.

I've messed with the cooling systems enough, and 99 times out of 100, the thermostat is the cause of all woes.

 

[Przybysz]

I guess I can try and get a new thermostat. But the 94 is such a pain to change... I spent like 3 hours trying to cram my hand behind that stupid metal pipe. Does anyone know how to take that thing out????