Coolant Leak

[DanielMaat89]

So back in June, I replaced my water pump as well as the thermostat, and the gaskets and o-rings for everything. Over the summer, I drove from North Jersey to North Carolina twice as well as countless trips to the shore and some towing. Never Lost a drop of coolant. Now that it is below freeing, I am loosing coolant from the pipe that sticks out of the block and goes into the outlet housing. It is only leaking when it is cold. I'm using the Toyota coolant and have no other leaks. Im wondering if I should replace all the O-rings and the outlet housing, or just do the o-rings. Anyone have this problem? It is an 09 with the 1GR-FE.

 

[neal0124]

If they are the original o-rings they are probably getting hard and slightly flattened. When it's hot they can swell up and seal better, but when cold can contract and lose their seal. I'd just replace the o-rings first and see if that fixes the leak. Do the cheapest and easiest fix first.

When I did the timing belt on my V8 I changed both of the o-rings on the thermostat housing and both of them were getting hard and were completely flat around their outer circumference. It doesn't get below freezing here in Los Angeles or cold enough for it to affect the o-rings so I never experienced any leaking from them, from the cold at least.