Mystery coolant loss - put on your thinking caps....

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IdahoDoug said:
I checked those metal lines over very carefully. In fact, that's why I was laying under there when I first heard the cat boiling noise.

DougM
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Doug:

I'm not sure if this is the same as on your truck, but part of the problem with the rear metal hose lines is that they are hidden under the cat heat shields. My hoses were completely shot and I ended up having to cut them off and replace with soft line to the rear heaters. Mine were in such poor shape that I only would have given them part of a season before they blew a hole.

I would think that that much of a loss would start to show, but it could boil off the heat shield as well? Were you able to see the condition of the lines under the heat shield -maybe with a mirror + flex lights?

If you have any doubt and don't feel like doing the work, you could always bypass the rear heater and see if things changed.

This is assuming that the coolant smell in the exhaust isn't a problem.

Good luck

Cheers, Hugh
 
Hugh,

Excellent idea to bypass the rear heater to narrow the search. I carefully eyeballed every inch of the rear heater lines except the section where it crossed over the top (the lateral section where it goes straight over to the rocker panel) and saw no problem. I was looking for pink crusties, evidence of water flow, anything. I pulled on the heat shield to flex it back where needed, and basically saw no evidence of leakage or any distress on the metal lines.

I sent an oil sample to Blackstone overnight, so I'll know about the oil tomorrow. Unless the water emulsion I found was simple condensation (It is that time of year), then I think Blackstone's going to confirm the coolant in the oil and I'll be joining the HG club.

My wife and I have switched cars and I'm driving the suspect rig. No hints of steam from the exhaust, starts and runs perfectly smooth. Strange.

DougM
 
I think I know how this thread ended up (I guess I should purchase the DVD :), but I am currently trying to figure out where the coolant puddle on the top lip of the radiator and behind the battery tray is coming from. '94 FZJ80, new radiator cap; not new radiator or hoses. Fresh coolant on top of the radiator after short drives, but no deposits on the plastic or rubber at the connection. Appreciable coolant loss with short drives, no coolant loss at all after a 800 mile round trip. Before I start YAHGT (yet another HG thread), I thought I would solve all external leaks. What exactly is the leakage mechanism for the upper hose? Or should I simply replace all radiator and heater hoses?

Thank in advance...


IdahoDoug said:
...Then I found a large leak on the large upper radiator hose block end. Cannot believe I had not noticed this before. Looks like a defective hose as it's oozing out the threads (new, also).

Idled the truck for 15 mins - no dripping. Then stuck a screwdriver in the throttle at 3200 rpm and waited for that upper hose leak to start dripping. It wouldn't, so I gave up and will just replace it. I was hoping for some combo of warm or cold or high rpms that would cause it to start flowing enough to make me happy I'd found the source of a loss of coolant that has now amounted to near 3 gallons over the last couple months. No such luck.
...
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aim said:
I think I know how this thread ended up (I guess I should purchase the DVD :), but I am currently trying to figure out where the coolant puddle on the top lip of the radiator and behind the battery tray is coming from. '94 FZJ80, new radiator cap; not new radiator or hoses. Fresh coolant on top of the radiator after short drives, but no deposits on the plastic or rubber at the connection. Appreciable coolant loss with short drives, no coolant loss at all after a 800 mile round trip. Before I start YAHGT (yet another HG thread), I thought I would solve all external leaks. What exactly is the leakage mechanism for the upper hose? Or should I simply replace all radiator and heater hoses?

Thank in advance...
Click to expand...

You know my truck does this as well, however I have an aftermarket radiator and also don't trust the top hose all that much. I assume it's from this hose since I can't figure out where else the coolant would come from. Both the top lid of the radiator and my battery get coolant on them but nothing is on the hose.

The top lid on my radiator is metal and the coolant has eaten through the paint in the channel is likes to collect in. :eek:
 
Silcone Hose

I used the silcone hose with the green outter and red inner. Used the lined clamps and costant torque clamps. Found the hose to be very hard to put on as it seemed a little smaller than the hose I replaced by lets say 1/8". No leaks for me at all and all has been good. I even replaced the hoses under the car to the back heater so evey heater hose in the LX is done with this hose.


I was thinking to fix a leaking tranmission cooler hose, new hose that can not get to seal from a very tiny drip every night, that I would use some great stuff gasket sealer and then crank it down with a constant torque clamp.

Might be that you need to clean and use some steel wool or something to smooth out the barb for a good seal.
 
Aim,

Fix your external leaks before making any HG-ish conclusions. The accumulation on the top of the stock radiators tends to be the upper O ring that runs all along inside where those thin metal "fingers" clamp the plastic top tank to the brass/copper radiator core. Some shops can repair this. In other words, the O ring encircles the entire top of the radiator - some 5 feet of O ring length. The O ring parts from Dan are around $40 but the labor costs and the quality of the resulting job would determine whether or not it's worth messing with vs a new OEM rad from Dan. The plus to a new rad is that it's plug and play - 4 hours in your garage to a perfect new radiator vs leaving your truck at a shop for a couple days while they attempt to get all those fingers pressing down equally and don't break any off.

So, fix that first. Send an oil sample to Blackstone in the interim and you'll have some hard data.

DougM
 
HG-fever-
Tail pipe sniffer don't be shy
We must unite.
My 80 has a sweat smelling tail.
That explains why I have been following these HG threads.
This would be a great poll thread.
Sweat smells with no coolant loss or sweat smell with coolant loss.
No sweat smeel with no coolant loss or no sweat smell with coolant loss.
 
fzj80kidpen said:
My 80 has a sweat smelling tail.
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Sweat usually does not smell sweet.

-B-
 
So the coolant sweet smell is different than the sweet smell of gasoline, right? Everytime I smell my exhaust it seems sweet to me, but it smells more like gasoline than anything else. This is probably due to the fact that I've been smelling it right at startup when it's cold. I noticed these things like to run rich when cold.

So I should be trying to smell for a coolant sweet which is more like vanilla, right? Also should it be after the truck is warmed up or when it's cold?
 
I know this is an old post, and IdahoDoug now sells headgasket dvd's, but what was the final conclusion. Was it a heater hose or head gasket. I am having the same problem. Truck isn't overheating, oil isn't sludged, and no smoke out the back. I know this only means nothing with these trucks.
 
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