Heater core restricted. Damaged, or plugged.Ok so I went back to the basics and I checked the hoses after a 30 minute trip they weren’t reversed. However The outlet hose was a great hand warmer in the cold but the inlet hose was hot enough to send u to the hopsital. so the coolant going out is a lot cooler than the stuff going in. Does this mean my heater core is bad???
The blower is trying to cool the heater core by using outside air (inside air if recirc)
The engine is trying to heat the heater core by pushing hot coolant through it.
In your case, the water is so restricted that the air is easily able to cool the core, which transfers insufficient heat to the air--and you have a weak heater.
If the outlet temp is that much lower than the inlet, the core and box aren't getting hot enough.I just don’t understand why it isn’t getting heat. The core inside the box gets hot and the box is hot why isn’t it transferring to the vents like it should
Bad move. The restriction belongs on the INLET side of the core. In fact, it's built-into the GM quick-connect fitting on the back of the TBI engine intake manifold. I don't know where or if it's a part of the LS heater system.I don't know if it was related to the LSx swap in my truck but I had to put a restricter in the line out on the heater core to get the heat to work for me.
GM had problems with exploding heater cores when the engine RPM was high. The system (radiator cap) pressure is added to by the dynamic (water pump pressure) and the two together was more than the heater core could take.
Yeah, I'd like to see higher duct temps than that.Checked mine this morning...
Outside temp 34
Floor and panel vent made no difference, it was around 130 at idle.
Driving 40-mph it went up to 145. It probably would have gone a little higher but I have a short commute.
Putting it on recirc added about 5–10 degrees.
This was with the a/c on and blower on high. Turning off the a/c made no difference. Heater core is original (1998).