Originally Posted by Slowered318
Having some troubles now.
Since I changed all the hoses and removed the bypass valve (from the recall) I've been experiencing a strange problem with my cabin heater. I have almost no heat at highway speeds but when I come to a stop/crawl I have plenty. Engine temp and coolant level seems to be normal, I bleed the coolant twice using the uphill method to remove any air, tried disconnecting the power to the heater core valve. Checked over the system a few times and still getting the same problem at prolonged speeds above 50.
I have a feeling I might have connected the heater core lines backwards but it doesn't make sense that would have any effect. The heater core is just a closed loop from the head to the water pipe or does it have some sort of check valve? I've pulled over a few times and both lines to the heater core are toasty warm. I don't want to replace the heater control valve or thermostat if possible, they both seem to be working.
This does not look right. I used this guide:
Here is how mine was done: