HG replacement almost done... coolant leak from back of engine
#1
HG replacement almost done... coolant leak from back of engine
Hi,
I've been working on this head gasket replacement on my '92 4Runner 3VZ-E for over 3 months now. Last night was going to be the big night to start it up for the first time. I was down to the last two steps: spark plug wires and coolant fill. We had pizza and beer and people over to witness the big event.
... And then coolant started draining from somewhere at the back of the engine.
I spent some time with a mirror trying to see where it was coming from... no dice. I removed the upper air chamber... still nothing: all hoses are connected, and the leak was coming from below the level of the cold water bypass unit.
I took the cold water bypass off... NOTHING. Still nothing apparent, and the leak is still below there.
So. I've never done anything with freeze plugs. I don't even know for sure what to look for to find them. But my very limited knowledge of them still leads me to wonder if that might be where my problem is. The block has sat with coolant in it this whole time -- I didn't get an FSM until late in the job, and didn't realize until then (after I already had it most of the way back together) that the block could be drained of coolant.
I live in the Portland, OR area. It has gotten cold here during the last few months, but not horribly cold... to my knowledge, the low during this time has probably been ~25 F. The 4Runner has been in a garage the whole time too.
1. Does anyone have any idea what this could be or what I should check next? Ideas that I can do without removing any other pieces are especially welcome...
2. Does anyone have a clear pic of the back of the engine showing the location of the freeze plug(s) back there?
3. Can someone explain if/how it could be a freeze plug issue? Would 25 F + coolant in the block have been enough to cause this?
4. Are there any other hoses I might have forgotten underneath the level of the plenum? I remember there's a metal pipe under the back of that, but I didn't think there was anything with it that I had to hook up.
5. Does anyone have a magic wand they can wave to make this go away?
Thanks,
Jason
I've been working on this head gasket replacement on my '92 4Runner 3VZ-E for over 3 months now. Last night was going to be the big night to start it up for the first time. I was down to the last two steps: spark plug wires and coolant fill. We had pizza and beer and people over to witness the big event.
... And then coolant started draining from somewhere at the back of the engine.
I spent some time with a mirror trying to see where it was coming from... no dice. I removed the upper air chamber... still nothing: all hoses are connected, and the leak was coming from below the level of the cold water bypass unit.
I took the cold water bypass off... NOTHING. Still nothing apparent, and the leak is still below there.
So. I've never done anything with freeze plugs. I don't even know for sure what to look for to find them. But my very limited knowledge of them still leads me to wonder if that might be where my problem is. The block has sat with coolant in it this whole time -- I didn't get an FSM until late in the job, and didn't realize until then (after I already had it most of the way back together) that the block could be drained of coolant.
I live in the Portland, OR area. It has gotten cold here during the last few months, but not horribly cold... to my knowledge, the low during this time has probably been ~25 F. The 4Runner has been in a garage the whole time too.
1. Does anyone have any idea what this could be or what I should check next? Ideas that I can do without removing any other pieces are especially welcome...
2. Does anyone have a clear pic of the back of the engine showing the location of the freeze plug(s) back there?
3. Can someone explain if/how it could be a freeze plug issue? Would 25 F + coolant in the block have been enough to cause this?
4. Are there any other hoses I might have forgotten underneath the level of the plenum? I remember there's a metal pipe under the back of that, but I didn't think there was anything with it that I had to hook up.
5. Does anyone have a magic wand they can wave to make this go away?
Thanks,
Jason
#4
Registered User
I'm not sure what the temperature of your coolant in the block would have to do with freeze plugs failing. If they were alright before the hg replacement and you didn't mess with them, they should still be fine.
I'm not familiar enough with the 3.0 to help you find your leak. Now if it was the 22RE....
Rob
I'm not familiar enough with the 3.0 to help you find your leak. Now if it was the 22RE....
Rob
#6
Yeah, it seems like it wasn't cold enough to cause it to freeze in there... I'm just having a hard time coming up with any other ideas about what could be leaking.
I might pick up a coolant system pressurizer... I've heard that might help me pinpoint the leak. Do y'all agree?
I'd like to be able to identify the problem before re-disassembling this any farther... I either need to remove the crossover pipe to check in front of it on the back of the block, or I have to remove the belts, etc, so I can take off the plenum.
I might pick up a coolant system pressurizer... I've heard that might help me pinpoint the leak. Do y'all agree?
I'd like to be able to identify the problem before re-disassembling this any farther... I either need to remove the crossover pipe to check in front of it on the back of the block, or I have to remove the belts, etc, so I can take off the plenum.
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