Just noticed a coolant puddle under the truck today when I left it running at high idle, which I have set at 1200 RPM's with a solenoid switch. Got scared the head gasket was an issue but we pressure tested the system tonight and it hold pressure just fine.

So where's this comin from.

 

Was the pressure test done with the engine hot, or under similar circumstances? I can usually find voolant leaks by there tattle tale streaks that they leave.

 

Same thing happened to my last week when it was cold. Lost probably a litre or more.

 

Didn't have the engine running but it was still hot. Just put the tester on, pumped it up and let it set and it help pressure. No leaks to be seen.

 

That seems kind of strange. Coolant reservoir have a crack in it? Weep hole? Freeze plug? I'm sure you have probably been through all that already. Doc you say yours did the same thing? Did you find anything or has it done it since?

 

I know a lot of equipments will have coolant leaks when it get quite cold out and the engine is started. Seems once the engine warms up the leak stops, same when the weather warms up. Not to the extent of a liter leaking though.

 

Played with it today. No leak at normal idle and still leaking at high idle. Truck is not running hot either, just sits at normal operating temps.

 

i hope its coming out the weep on the pump instead of head gasket.

 

Already pressure tested it and it holds pressure so I'm not worried about the head gasket.

 

where is it pooling fluid under the truck.