Coolant Leak (water pump)?

[Bostonbruck]

My car decided to randomly leak a bunch of coolant. It happened when the car was on jack stands for about a month. I can’t view any sort of leak from the top of the engine. From under the car it appears to be leaking toward the back of the engine on the sway bar. It appears to be the water pump. Any thoughts before I start replacing parts? There is a video linked below.

The car has 115k miles and most of the cooling system is original. The coolant hoses were replaced and the system was tested a few years back. I plan on doing the whole cooling soon. Any thoughts? Thank you.

-Boston

https://m.youtube.com/watch?v=cB5E9TgFV4s

[eacmen]

Weird that it would just start doing that while on jackstands. Could just be the lower hose? Trace down the source of the leak before throwing parts at it, refill the system if needed to track it down.

If buying parts:
Get the OE water pump with the metal impellar. Replace with OE tstat at the same time. Consider getting the updated viton o-ring kit from the forum here (forget his username). If you have a shop that can dunk tank the radiator to clean it out do that, otherwise consider getting a new/updated rad with metal end tanks.

[Bostonbruck]

Weird that it would just start doing that while on jackstands. Could just be the lower hose? Trace down the source of the leak before throwing parts at it, refill the system if needed to track it down.

If buying parts:
Get the OE water pump with the metal impellar. Replace with OE tstat at the same time. Consider getting the updated viton o-ring kit from the forum here (forget his username). If you have a shop that can dunk tank the radiator to clean it out do that, otherwise consider getting a new/updated rad with metal end tanks.

I also thought it was strange that this happened while it was on stands. It was on stands for over a month while installed the headers, and did the window seal DIY. The leak started about half way through. Maybe the seals dried out during the time that it wasn't driven? It's a pretty big leak, it will leak about a half gallon per hour or 2.

[ethan]

If buying parts:
Get the OE water pump with the metal impellar. Replace with OE tstat at the same time. Consider getting the updated viton o-ring kit from the forum here (forget his username). If you have a shop that can dunk tank the radiator to clean it out do that, otherwise consider getting a new/updated rad with metal end tanks.

It's my understanding that the OE pumps use a composite impeller to reduce bearing wear at high RPMs. Though that could be a weak point (I have heard of OE impellers failing at relatively high mileage), I also had a Saleri metal impeller unit develop significant bearing play very prematurely (luckily I purchased it from FCPEuro.)

Can anyone corroborate?

[eacmen]

I also thought it was strange that this happened while it was on stands. It was on stands for over a month while installed the headers, and did the window seal DIY. The leak started about half way through. Maybe the seals dried out during the time that it wasn't driven? It's a pretty big leak, it will leak about a half gallon per hour or 2.

Just gotta get in there with a flashlight and mirror. You could fill the system and turn the heat on highest temp but lowest fan setting. There is an electric aux water pump that will run with just accesory power. With the pump running the leak source should be gushing.

You could also start the engine to get coolant pumping. But don't let it run for too long without the cooling system working.

[Obioban]

It's my understanding that the OE pumps use a composite impeller to reduce bearing wear at high RPMs. Though that could be a weak point (I have heard of OE impellers failing at relatively high mileage), I also had a Saleri metal impeller unit develop significant bearing play very prematurely (luckily I purchased it from FCPEuro.)

Can anyone corroborate?

You are correct and your metal impeller experience is typical.

[Bostonbruck]

Update: it was leaking from the water pump/thermostat, as expected