strange coolant leak.

[oldgreymare99]

Hey guys I have a 1999 chevy K2500 crew cab with the 5.7. This morning I noticed a puddle on the drivers side under the rear door. My kid left a cup in his car seat so I assumed it was spilled lemonade. It puddled again this afternoon and upon inspection I find that it's coolant. If I open the door you can see where it is running between the door seal and the carpet. I removed the sill plate and pulled the carpet back to see where it was coming from but I couldn't narrow it down. My truck does not have rear A/C. My question is this has to be a leaky heater core right? I looked around the A/C box for leaks and didn't see anything obvious. What is really weird is that the A/C box is on the passenger side, but I am leaking coolant from the drivers side rear. Any thoughts from you guys would be greatly appreciated.

 

[Erik the Awful]

Are you absolutely sure it's not lemonade? Coolant and lemonade - both smell sickly sweet, both yellowish when filtered through all the junk in your carpet.

Have you pulled back the carpet under your heater core to see if it's wet? If so, there's no need for further investigation, replace your heater core. If it's dry, it was lemonade.

 

[oldgreymare99]

It keeps puddling after every drive. I'm going to bypass the heater core today and see what happen.

 

[stutaeng]

It's not when it rains? I had read here there's a common leak by the cowl from a screw head.

A few days ago it rained cats and dogs here. I went to move my truck and saw a leak. I never realized I had that. Never could understand why it's always musty in there. I don't daily drive that truck, it mostly just sits currently.

I need to find that thread to see what needs to be done, otherwise I'll forget...

Edit: Oops, just realized you said your leak is coolant. Sorry.

 

[Jeepwalker]

Is your coolant tank low? Or you been adding coolant? You should be able to observe a drop in coolant either at the overflow tank, or the radiator (if it's not properly drawing it from the overflow), unless the leak just started.

 

[east302]

It keeps puddling after every drive. I'm going to bypass the heater core today and see what happen.

Is the carpet/firewall pad wet at the heater core?

 

[Keeper]

Heater core peeing into driver's side duct for rear vents?

 

[someotherguy]

Heater core peeing into driver's side duct for rear vents?

^^^ almost for sure nailed it there.

Richard