Good afternoon I'm looking for some advice on a strange issue with the cab heater of my D22 2.5 diesel 4x4 truck, a few weeks ago the heater stopped blowing any hot air, the temperature of the engine was normal, with this I went ahead and got stuck in swapping out the thermostat and water pump for new, flushing the rad and heater matrix which all seem to run through ok, but this has not solved the issue I only get heat is i rev the engine above 3000 to 4000 then it just cools back down and blows cold air again? the top hose seems to pressurise but no fluid comes out the overflow at the radiator cap so cant be that high? Im now at a loss.. please help.
D22 Heater issues
- Thread starter alan7522
- Start date
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the d22 heater system is a little odd in that its not controlled by the water. the water flows through constantly and the heating is controlled by the airflow through the heater core. odds are the flap (mix door) that controls the air flow through the core is stuck or not working.
I have checked this and it is working fine I am just getting no circulation and it makes no sense if I take the top hose off the radiator I get no water pumping out of either the pipe or the top of the radiator? and no water pumping through the metal pipes to the matrix yet I can detect a blockagee anywhere because i can add the hose to either and water starts running through it all?
i'm not up on the 2.5 (what year? or what exact engine).
later ones yd25 could have blocked egr cooler as that feeds the heater.
anything earlier its hard to say because heater circuit is always on, there should always be flow short of the water ports in the head being blocked.
even if radiator gets blocked, water is still pumped through the heater. so you should still get heat.
only thing that will make it run cold is thermostat stuck open and engine is running cold. tho gauge should indicate that.
if you take it for a drive, does the heater pipes get hot?
no water moving in the radiator, is that after a decent drive. you guys are in winter at the mo what the outside temps?
if you take the heater hoses off and start the engine does water come out of the hoses?
if no water coming out then its either pump problem or blockage in the head.
but you have changed the pump, tho what does the old pump look like? anything missing?
later ones yd25 could have blocked egr cooler as that feeds the heater.
anything earlier its hard to say because heater circuit is always on, there should always be flow short of the water ports in the head being blocked.
even if radiator gets blocked, water is still pumped through the heater. so you should still get heat.
only thing that will make it run cold is thermostat stuck open and engine is running cold. tho gauge should indicate that.
if you take it for a drive, does the heater pipes get hot?
no water moving in the radiator, is that after a decent drive. you guys are in winter at the mo what the outside temps?
if you take the heater hoses off and start the engine does water come out of the hoses?
if no water coming out then its either pump problem or blockage in the head.
but you have changed the pump, tho what does the old pump look like? anything missing?
Just to jump in here and put a slightly different twist on things. (2011 D22, YD25, single cab)
My heater works really well if you want to warm things up, pretty damn hot in fact!
But turn it off and the cab still get warm in traffic. Almost to the point of needing the AC on at 28c outside temp!
What would I need to look at? And how do I get to it?
My heater works really well if you want to warm things up, pretty damn hot in fact!
But turn it off and the cab still get warm in traffic. Almost to the point of needing the AC on at 28c outside temp!
What would I need to look at? And how do I get to it?
single cabs always get hot quickly.
if it was 28c out side i would have aircon already. that sounds pretty normal to me.
the cab is always going to get heated from the engine itself via the firewall, i suspect the insulation is pretty minimal as they where a budget ute. plus the heater actually runs all the time, what changes is the air flow through it.
if it was 28c out side i would have aircon already. that sounds pretty normal to me.
the cab is always going to get heated from the engine itself via the firewall, i suspect the insulation is pretty minimal as they where a budget ute. plus the heater actually runs all the time, what changes is the air flow through it.
