2005 Chevy Suburban - coolant pouring out of bottom of engine block

[Gator Aggie]

My son and I have encountered a troubling issue with our 2005 Suburban. When we try to add coolant with car not started, the coolant runs straight out on the ground below the bottom of the engine block? The car will start and run a few minutes and then starting getting hotter and then smoking from the back of the engine. There looks like a black hose under the engine near a firewall where all of the coolant is flowing out. All sounds bad but this problem and diagnosis is beyond our auto expertise.

 

[blondie70]

I would get under there and take some pics with coolant (water)running out and post them for the guys here to see. Zero in on the leaking spot.

 

[strutaeng]

Yeah, what @blondie70 said.

The heater hoses for the rear heater run on the passenger side near the wheel well against the firewall (but not really under the engine). Maybe it's those?

Did the engine freeze up at any point recently? Was it running well prior to this? When did it start?

You shouldn't be trying to run the engine if the coolant is escaping. You are going to overheat the engine and ruin it, if it hasn't happened already.

 

[Gator Aggie]

Yes we will take pictures some today. Engine hasn't froze up and we really haven't driven it at all in the last 5 or 6 weeks. This suburban also have a mysterious power drain going on that I think might be the instrument control cluster. Once we can get the coolant leak fixed, we can start "Longmire" up again and finish testing the instrument control cluster.

 

[strutaeng]

If it hasn't frozen, I guess you can take a look at the "core plugs" on the lower sides of the engine. There's at least one on each side, and are recessed hex plugs made of brass. Maybe one of those is leaking? The passenger side core plug is behind the starter. The driver's side is this very large plug.

 

[Gator Aggie]

This bolt and plug part is located on the upper back of the engine. Pretty hard to get to and near where one of the engine grounds runs and gets connected. This was missing on my 2005 Suburban and thus the coolant was bubbling out and then spiling out on the ground. When we were searching for grounds to locate a parasitic battery drain, the bolt was loosened and not retightened and thus it popped off later when suburban was started and run. Luckily we found another one pretty quickly at local junkyard, installed it on suburban, and it now seems to run solid with no leaks. Although it did take quite a bit of coolant to get the system filled back up.

Still searching for the source of this major battery drain but think it might be a bad instrument cluster (as suggested by someone on this forum!) but still need to prove it out further.