Coolant leak and smell inside

[comfreak]

UPDATE

Performed a combustion leak test, results were negative. No head gasket leaks.

Installed a new water pump (and thermostat) and found the issue was the seal(s) between the pump and the engine. They disintegrated and caused a slow leak, likely once it cooled down I would suspect. There was a ton of old coolant gunk (see images) behind the pump coming from the seals.

Scraped off the old seal and gunk, changed the belt, and put it all back together and it's running fine. Now it's a waiting game for any leaks and the smell to go away.

 

[R467X]

Consider adding some cheap UV additive to your coolant and run your engine until warm. Makes it extra easy to find leaks. It could be a number and may not be the pump at all.

I second replacing all the hoses. I did a complete replacement two years ago on my 250k mile suburban. Water pump, radiator, fan, all hoses. Took a couple of hours. Fairly easy if you know what you're doing.

 

[Fless]

It could be a number and may not be the pump at all.

What "number" would cause something like this?

 

[R467X]

What "number" would cause something like this?

Number of things*

 

[mjgirard]

I had a water pump leak too in my 2001 Tahoe with 125000 miles. I decided due to the age of my Tahoe to replace anything associated with the water pump at this time so I did not have to do piecemeal jobs.
I replaced the following: water pump, radiator, thermostat, serpentine belt tensioner, pulley, new belts, all hoses and T-connectors, coolant recovery tank and cap. I really did all of this for preventive maintenance and to get my Tahoe ready for the summer vacation trips.
Good luck with the work.