93b2600i
+1y
91 b2600i
I am getting no heat in the cab. I ran a hose through the heater core and the water is running right through.
Any ideas?
I am getting no heat in the cab. I ran a hose through the heater core and the water is running right through.
Any ideas?
Cusser
+1y
Perhaps your thermostat is opening too soon or too-low a temperature. My B2200 heating improved a ton when I - only - installed a new Stant 192/195F factory setting thermostat.
Anyway, with all, you need to make sure that ALL the air is bled out of the cooling system, important. I jack up the front of the truck, take off the cap, and run the engine adding 50/50 as needed for like 20 minutes, then re-cap. Easier to drive the truck if I remember to lower off the jack.
Get the truck warmed up, and feel both connections to the heater box at the rear of the engine compartment. If both are hot, then you don't have an engine issue, the issue would be under dash, like outside air getting in because the cable-operated door/flap is not closed, or the door/flap that directs the air over the heater core is not operating.
Get a helper to turn the controls and slide the heater levels, look underneath the dash (from both sides) and look up and towards the center to confirm whether moving each control actually does operate something. On my truck one of the cables had slipped off a rod, so I had to re-attach.
Anyway, with all, you need to make sure that ALL the air is bled out of the cooling system, important. I jack up the front of the truck, take off the cap, and run the engine adding 50/50 as needed for like 20 minutes, then re-cap. Easier to drive the truck if I remember to lower off the jack.
Get the truck warmed up, and feel both connections to the heater box at the rear of the engine compartment. If both are hot, then you don't have an engine issue, the issue would be under dash, like outside air getting in because the cable-operated door/flap is not closed, or the door/flap that directs the air over the heater core is not operating.
Get a helper to turn the controls and slide the heater levels, look underneath the dash (from both sides) and look up and towards the center to confirm whether moving each control actually does operate something. On my truck one of the cables had slipped off a rod, so I had to re-attach.
93b2600i
+1y
Changed the t-stat. It was one that was locked opened. It was a fail safe type. I put in a 192 stant. Truck runs better. Still no heat. Air circulates. hoses in and out of heater core are hot. Any other ideas?
Cusser
+1y
Since both are hot, then you don't have an engine issue, the issue would be under dash, like outside air getting in because the cable-operated door/flap is not closed, or the door/flap that directs the air over the heater core is not operating.
Get a helper to turn the controls and slide the heater levels, look underneath the dash (from both sides) and look up and towards the center to confirm whether moving each control actually does operate something. On my truck one of the cables had slipped off a rod, so I had to re-attach.
Since both are hot, then you don't have an engine issue, the issue would be under dash, like outside air getting in because the cable-operated door/flap is not closed, or the door/flap that directs the air over the heater core is not operating.
Get a helper to turn the controls and slide the heater levels, look underneath the dash (from both sides) and look up and towards the center to confirm whether moving each control actually does operate something. On my truck one of the cables had slipped off a rod, so I had to re-attach.
mazdatweaker_2
+1y
I think your heater valve is stuck shut so hot water isn't being diverted into the heater core to dump the heat.
I believe the heater valve is on the left side of the heater core near the floor and as Cusser has suggested have someone move the levers while you look under the dash to see the cables ends where they connect to verify movement.
I believe the heater valve is on the left side of the heater core near the floor and as Cusser has suggested have someone move the levers while you look under the dash to see the cables ends where they connect to verify movement.
dynomike
+1y
I've seen the temp control adjustment switch break behind the dash. This not allowing the cable to do is job down below by drivers right foot.
scotch
+1y
+1 on bleeding and checking control/valve and air doors.
Just curious. How long was the truck engine (gauge, not the cabin heat) running cold? Meaning cold with the stuck open thermostat? And it was the kind that was designed to stick open and not just that the spring rusted or failed?
The reason I as is because we have been having a thermostat discion over on MazdaTrucking.com.
If yours was fact was a fail-safe type, did the truck ever have any overheating issues that you are aware of that prompted it to stick open? There a lots of reports on the internet of these motorad fail-safes sticking open without any serious overheating. So I was just curious if that was your situation.
Just curious. How long was the truck engine (gauge, not the cabin heat) running cold? Meaning cold with the stuck open thermostat? And it was the kind that was designed to stick open and not just that the spring rusted or failed?
The reason I as is because we have been having a thermostat discion over on MazdaTrucking.com.
If yours was fact was a fail-safe type, did the truck ever have any overheating issues that you are aware of that prompted it to stick open? There a lots of reports on the internet of these motorad fail-safes sticking open without any serious overheating. So I was just curious if that was your situation.
93b2600i
+1y
It was a fail safe type. I think it lasted about 6 months, but I am sure it was stuck open within 4 months. The fail safe t-stat was stuck opened as designed. No rust on it. Coolant was clean.
I plan to change out the heater core. I check water flow with a water hose, it runs through the core. Coolant was clean. I suspect that the previous owner might have put some of the head repair fluids in it and clogged it up. Since the heat is luke warm at best, I suspect that the majority of the core is clogged. Looks original.
I plan to change out the heater core. I check water flow with a water hose, it runs through the core. Coolant was clean. I suspect that the previous owner might have put some of the head repair fluids in it and clogged it up. Since the heat is luke warm at best, I suspect that the majority of the core is clogged. Looks original.
befarrer
+1y
You could have a bunch of fluff, and debris in the heater core fins, or the flapper door that controls heat (not the coolant valve) may be not working. Your heater core valve is working, otherwise you would not get heat on both heater core hoses, as the heater valve blocks all flow through the heater core.
Cusser
+1y
Did you check all those cables flaps under the dash?
Personally, the LAST thing I'd do would be remove the dash and heater core, only after I explored all other possibilities under the dash, or flushing the heater core with dilute phosphoric acid, vinegar, or commercial flush product.
But if you must, see the how-to:
Personally, the LAST thing I'd do would be remove the dash and heater core, only after I explored all other possibilities under the dash, or flushing the heater core with dilute phosphoric acid, vinegar, or commercial flush product.
But if you must, see the how-to: