Coolant leak from unknown location

[JOlsen]

Ok so here's what happened. Drove home last night about 20 miles a/c blasting the entire way. Park the truck and run upstairs foe about 10 minutes,I come back down to a lake of coolant coming from somewhere above transmission firewall area. I checked the level and it was slightly low so I refilled and started the truck. No temp issues at all and since then I have seen 0 coolant. I haven't been able to replicate it in the last 24 hours. Help me out here. Only thought I have is heater core but there is no fluid inside cabin. HELP

 

[Don Hall]

Year of truck, and engine size?

 

[Trainmaster]

Go look for the leak. The 1st Generation cars tend to develop head gasket leaks above the starter after 200K miles when under pressure. Mine leaked a bit of coolant and oil there at 215K miles. But you've got lots of other places to check first. Good luck.

 

[JOlsen]

99 5.4l 2wd

And I looked in that area and it seemed dry. very strange. I have driven it the last day about 150 miles and not a drop. But still worrysome

 

[Don Hall]

.......... a lake of coolant coming from somewhere above transmission firewall area. I checked the level and it was slightly low so I refilled and started the truck. No temp issues at all ........

You sure the liquid was coolant? "A lake of coolant" would measure more than "slightly low".

What other liquid could it be? Brake fluid, transmission fluid, power steering fluid, oil, differential fluid, window washer fluid, that is all I can identify.

Leaks seldom, if ever, heal themselves, so it would be easier to solve this dilemma if the fluid was something other than coolant. Since there was/is no sign of overheating, and no sign of additional leaking, it would/should follow that whatever was leaking emptied its' reservoir, which would account for no further leaks, and the coolant maintaining engine temp.

I'm sure JOlsen knows the difference between coolant vs the other fluids, so I am not challenging his intellect.

 

[JOlsen]

You sure the liquid was coolant? "A lake of coolant" would measure more than "slightly low".

What other liquid could it be? Brake fluid, transmission fluid, power steering fluid, oil, differential fluid, window washer fluid, that is all I can identify.

Leaks seldom, if ever, heal themselves, so it would be easier to solve this dilemma if the fluid was something other than coolant. Since there was/is no sign of overheating, and no sign of additional leaking, it would/should follow that whatever was leaking emptied its' reservoir, which would account for no further leaks, and the coolant maintaining engine temp.

I'm sure JOlsen knows the difference between coolant vs the other fluids, so I am not challenging his intellect.

Yes definitely coolant/water. Actually this has made me want to flush the system even more then before because whoever owned it before had it filled with a majority water.

 

[99WhiteC5Coupe]

A/C condensation.....

 

[stamp11127]

If you have a DMM, set it to volts, place the red lead on the battery positive - negative lead in the coolant with the engine running. If you have anywhere near .5 volts or more you might want to replace the heater core and radiator in the near future before they give up the ghost on you.

 

[Plati]

Yes definitely coolant/water. Actually this has made me want to flush the system even more then before because whoever owned it before had it filled with a majority water.

This might be a red herring BUT .... straight water has a boiling point of 212F. Straight antifreeze (ethylene glycol) has a boiling point of 387F. A (proper) mixture of the two has a boiling point somewhere in between. Need to run the proper mixture for that and other reasons (freezing point, anti corrosion, etc). Should not use straight H20

 

[Plati]

If you have a DMM, set it to volts, place the red lead on the battery positive - negative lead in the coolant with the engine running. If you have anywhere near .5 volts or more you might want to replace the heater core and radiator in the near future before they give up the ghost on you.

At what location on the vehicle would you place the negative lead in the coolant? And NOT by taking cap off radiator on HOT engine!