3vze losing massive amounts of coolant

[ozzyleven]

Sometimes I have to ask myself wtf did I ever do to this truck? Driving down the highway happily in the 94 3.0, hear a noise that I first thought was just slush kicking up, look at the temp gauge and its about ready to hit the red. Pulled onto the shoulder and I see coolant coming off the drivers side of the engine like a garden hose. The entire system was drained in a about a minute. 100 dollars later to tow it, it's sitting in front of my house.

So, what things cause a big leak like this? I have a block heater in that general vicinity of all the coolant loss. It seems like its still in there good when tugging at it but nonetheless it has become suspect number one. Oil cooler is also over there. I've known for awhile that it was seeping oil. Is there anyway it could leak coolant without contaminating the oil? Because the oil is fine. I may or may not let the mech handle it depending on the weather. Was going to at least try to troubleshoot it. Any other areas I should watch when i fill it back up? Anyone got a diagram that shows all the freeze plugs. I think there are three on each side of the block, but what about the head? Just one at the rear? Thanks guys! I'm about ready to jump on the I'm selling my 4runner bandwagon, but if this doesn't cost me too much I might just keep her

 

[BucknutBob]

Well, saying it's "coming off the driver's side" doesn't really narrow things down for us to help, but I'll throw this out anyway--the coolant hose from the throttle body to the coolant bypass block on the back never gets any attention until it blows, and would release on the driver's side. Of course that block heater you mentioned is a likely culprit, too; especially if the flow is lower than the heads. No matter what it is, it shouldn't be too ridiculous to fix--a fast-flowing issue like that is something external that can be replaced quickly. Head gaskets and more serious issues don't act like that.

 

[4runnin83]

Mine overheated in Sept. Same thing, lost all my coolant very fast. My radiator had a hole on the back side and coolant was spewing out. I replaced the radiator/thermostat and shes been fine since. Good luck.

 

[ozzyleven]

All the hoses are intact from what I can see. I know the one your talking about in that bypass block. Those have been replaced. It seemed like it was coming from the oil filter area. It happened so fast that I saw a gush of water and then coolant all down the drivers side. Still need to go fill it up, too cold. Going to wait till Monday for warmer weather.

 

[4runnin83]

Are you still running the original radiator?

 

[ozzyleven]

It is the original but got overhauled a couple months ago. Couple pinholes got patched, new tanks, thorough cleaning. Pretty sure it's not leaking. Is still holding some coolant. Anyways the coolant is all over the drivers side, a little was on the fan blades, not on the front or radiator (like on the skid plate).

 

[4runnin83]

It is the original but got overhauled a couple months ago. Couple pinholes got patched, new tanks, thorough cleaning. Pretty sure it's not leaking. Is still holding some coolant. Anyways the coolant is all over the drivers side, a little was on the fan blades, not on the front or radiator (like on the skid plate).

Thats exactly how mine was, it can be clogged w/ rust and other minerals... Just saying, its worth the 150 bucks for a new one.

 

[NorCalBorn]

Checked the obvious stuff yet, like the bottom left inlet to the radiator or the outlet @ the block? Hoses come loose and the older style plastic block outlet (where your thermostat is) like to crack if old and brittle.

 

[Tanner]

My advice would be: take out thermostat. Remove top coolant hose from the radiator. Take a garden hose, put in top radiator hose and put a rag around it so it'll allow some pressure to go through the cooling system. Turn the water on and see where the water is coming from. Not only will it flush the cooling system out, it'll also show where the leak is coming from.

 

[ozzyleven]

Did the hose thing today, looks like the block heater is the culprit. Didn't even have to pressurize it or anything. It was pretty obvious were its coming from. The o-ring was torn in half and the whole thing came out pretty easily. The seal on the oil cooler need to be replaced anyways (poking around, the leak has gotten a lot worse!) and I don't have the patience to put my hands in tiny spaces this week while its 0 degrees out. Love working on the trucks when its nice, but winter time, my mechanic gets a lot more business from me I was quoted $90 to fix the oil cooler a couple months ago. Hopefully the offer still stands and they can throw a new block heater in for not too much more.