So, waterfall noises abound after replacing everything cooling related. Been this way for weeks. And weeks... and weeks. I've pressure tested, found the a loose hose clamp on the throttle body plate, fixed that, no more leaks... but still had waterfall noises coming from the heater core. So today I finally rented a block test kit and gave it a go. Results: no exhaust gases found.

To be honest, I wish there were because it would finally end this saga of trying to figure out the source of this air in the system.

I'm all out of ideas. I guess I live with this? Temps are fully in spec. IDK. ¯\_(ツ)_/¯

 

Bleeding the coolant system is a pita in a D2. Guys will say just lift up the coolant reservoir and you’re all good. Whenever I change the coolant, it takes for ever to get all the air out.

The waterfall sound is usually the heater core. Try turning the heat on full blast with the reservoir tank raised and cap off and bring it up to temp. Maybe give it a rev or two to get the coolant flowing.

Honestly, I feel like I add coolant for months after I do a flush.

 

Or park on an incline, or jack the front up, let it run, open bleeder screw, let air out.

 

Heater core probably plugged up letting only a pinhole spray through. Not enough flow to push the air through the other side. Is your heat super hot or luke warm

 

there's no need to turn the heater on. coolant flows through the heater coils continuously, regardless of the temperature setting.

 

The problem is the heater core is below the heater hoses, and at idle when most people bleed the air the water pump does not have enough flow to push water through the heater core. Try this:

1. Rev engine to 3000 rpm, open bleeder screw.
and if that does not do it, remove heater hose on cold engine (not the one coming from the intake, the other one), start engine, rev engine until coolant flows out of hose. If you want to capture the flow you can put a longer hose on or put a splice fitting in and run it in to the catch tank. Once you have the core flushed and filled with water it will not refill with air.