Coolant leak

Looks like I’m slowly loosing coolant out of the resivor. I did the water pump maybe 2.5 years ago. I’m suspecting that it’s coming from the thermostat housing since it looked to be caked all over and sometimes I can even see it glistening from moisture. So I’m pretty certain it’s coming from the thermostat housing.

This brings me to a few questions/ideas.

1. If I were to redo the water pump job would you suggest using some sort of RTV in addition with the gasket itself for extra sealing power? When I first did this job I noticed that the shop that had previously done the WP used a lot of rtv when I took the bad WP off. I had to scrape a lot of it off before I installed the new WP gasket. Should I be doing that too? Or was the shop just being cheap?

2. Last time I did the WP I ended up removing 1 or 2 of the thermostat studs when taking the nuts off. I believe I reinstalled them with thread locker but honestly can’t remember for sure if I did. Is this a common leak point due to loose thermostat studs? Could I simply just go in there and attempt to tighten the nuts without disassembling anything? Are they even accessible? I’ll check myself if they are soon but has anyone done it before?

No codes related to this. V6. 315k miles. This is my dd. The WP shouldn’t be anywhere near being replaced since it’s not even 3 years old, but here we are.

I’ll upload some pictures soon.

 

Here she is in the mean time.

 

1 - if you’re using the factory Toyota or Aisin metal gasket, I would not use any RTV.

2 - thread lock shouldn’t be require. You can try to retighten but be very careful as you can crack/break an ear off the housing. The o-ring gasket on the thermostat is supposed to seal excessive gaps and prevent leaks.

 

The Toyota factory metal gasket is the best option. I used this on my 3RZ rebuild and it’s working great after 30k. It’s also looks clean, because no RTV is required.