E46Fanatics - View Single Post - Heater core coolant leaking externally?
View Single Post
Old 02-13-2020, 04:39 PM   #2
Registered User
Join Date: May 2017
Location: Boston
Posts: 711
My Ride: '05 330CiC
Go over your work.

DO NOT use stop leak

If you used aftermarket heater pipes, they can be tricky to install without leaks. I try to use OEM pipes, but will use aftermarket pipes with OEM o-rings, which seems to work out. I also test them after install before putting intake manifold on, by hooking up all coolant pipes and hoses, install a special gutted thermostat housing I have, fill with distilled water and pressurize with <20 psi

In your case I would pressurize the cooling system - I use a compressor, but you can use a coolant pressure tester from harbor freight- and shine a light through the intake near were heater pipes enter block. check for leaks. If they are dry check the rest of your work.
Effduration is offline   Reply With Quote