Heater issues

Headlights to tailights and everything in between.

Moderators: Helpinators, Moderators

Post Reply
ferrari494
Second Gear
Posts: 263
Joined: Sat Mar 05, 2005 5:00 am
Location: Seattle, WA

Heater issues

Post by ferrari494 »

Replaced the heater core, and it all works just fine, coolant cycles through the entire system, but the temperature inside the car will not warm up! The HVAC controls work, and the little doors open and close and the blower motor works, when you push the different settings they all work correctly, it just won't warm up. The Hayne's manual talks about "the heater control valve being shut" what is that? Any other ideas?
'93 Subaru Legacy Turbo Sedan, 5mt
vrg3
Vikash
Posts: 12517
Joined: Sun Nov 03, 2002 2:13 am
Location: USA, OH, Cleveland (sometimes visiting DC though)
Contact:

Post by vrg3 »

You're sure coolant is cycling through the entire system, including the heater core? With a completely dry heater core it may be hard to get all the air out; you may want to disconnect the heater hoses from the engine and pour coolant directly into them (maybe into one until it comes out the other).

There is no heater control valve aside from the door that controls airflow through the heater core.
"Just reading vrg3's convoluted, information-packed posts made me feel better all over again." -- subyluvr2212
ferrari494
Second Gear
Posts: 263
Joined: Sat Mar 05, 2005 5:00 am
Location: Seattle, WA

Post by ferrari494 »

I hate to sound like an idiot...but as I look at it from the engine bay, the pipe that brings coolant into the heater core is on the left correct?
'93 Subaru Legacy Turbo Sedan, 5mt
vrg3
Vikash
Posts: 12517
Joined: Sun Nov 03, 2002 2:13 am
Location: USA, OH, Cleveland (sometimes visiting DC though)
Contact:

Post by vrg3 »

The heater's hoses meet the engine in the rear driver-side corner. One attaches to the water manifold (under the intake manifold) and the other goes to a pipe that goes down to the water pump.

They're bigger hoses than most of the other coolant lines -- they're 15mm ID (about 7/8" outer diameter) and both go through the firewall.
"Just reading vrg3's convoluted, information-packed posts made me feel better all over again." -- subyluvr2212
ferrari494
Second Gear
Posts: 263
Joined: Sat Mar 05, 2005 5:00 am
Location: Seattle, WA

Post by ferrari494 »

Correct, I replaced those hoses a few months ago. The one going to the leftmost side of the heater core is warm when the car is running, and the one going to the rightmost side of the heater core(as looking in the engine bay) is cool. But, I disconnected the cooler of the two hoses right up against the firewall, and it has coolant running through it.
'93 Subaru Legacy Turbo Sedan, 5mt
vrg3
Vikash
Posts: 12517
Joined: Sun Nov 03, 2002 2:13 am
Location: USA, OH, Cleveland (sometimes visiting DC though)
Contact:

Post by vrg3 »

Hm, interesting. All I can think of is that there might not be that much coolant running through it. Didja try sticking a funnel in the hose and pouring coolant in? Any bubbles come out?

The pipe going to the water pump is the water leaving the heater core. Is that the one that was cooler?
"Just reading vrg3's convoluted, information-packed posts made me feel better all over again." -- subyluvr2212
ferrari494
Second Gear
Posts: 263
Joined: Sat Mar 05, 2005 5:00 am
Location: Seattle, WA

Post by ferrari494 »

yeah, just let it run and after about 20 mins it all ran perfectly...but once again, thanks for the help!
'93 Subaru Legacy Turbo Sedan, 5mt
vrg3
Vikash
Posts: 12517
Joined: Sun Nov 03, 2002 2:13 am
Location: USA, OH, Cleveland (sometimes visiting DC though)
Contact:

Post by vrg3 »

Oh, good. No problem.
"Just reading vrg3's convoluted, information-packed posts made me feel better all over again." -- subyluvr2212
Post Reply