2005 D22 Navara ZD30 heater issues

[geebz]

Hello,

I'm hoping someone can point me in the right direction, I have an interesting heater issue.

The ute runs fine, the engine heats up as normal, sits at optimal temps when running, and doesn't overheat at all.

However, the heater seems to stop heating when I am idle.
I can be driving along (once warmed up), turn the heater on, hot air, no issues.
The moment I come to a traffic light or stop and idle, it just starts blowing cold air; when I take off again, the heat returns.
I can even be driving down the freeway at 100km/h with the heater on, nice and toasty, put it into neutral and just coast, heater goes cold, back into gear and accelerate, and the heater warms up again.

I've checked the following;
- coolant levels are fine.
- both hoses into the firewall (I believe these go to the heater core) are nice and hot.

The only thing I can think of is maybe the thermostat.
Have any of you run into this issue?

Thanks

 

[tweak'e]

thermostat stuck open or has been removed.

 

[Erick]

There is a little hose/pipe that runs from heater line down to the egr setup under intake manifold. Try blocking that temporarily and see if there is any difference.

 

[tweak'e]

There is a little hose/pipe that runs from heater line down to the egr setup under intake manifold. Try blocking that temporarily and see if there is any difference.

i do not recommend doing that as that will overheat the egr valve. the only problem that line could cause is if your leaking coolant.

 

[geebz]

i do not recommend doing that as that will overheat the egr valve. the only problem that line could cause is if your leaking coolant.

I was going to ask Erick what the purpose of doing this is?
But thank you for clarifying.

I'm going to replace the thermostat shortly, looks like it's a little difficult to get to, but in one of the videos I watched, the guy took off the front passenger side wheel, which made it a little easier to get to.

 

[Erick]

If ur worried about egr valve overheating temporarily do the blank job. But the heater in my 2005 d22 works better some days than others. But always enough to get by, but I’m N Qld. We can get a frost sometimes, lol

 

[tweak'e]

the egr valve won't make any real difference to the heater.
the thing with d22 is the heater runs all the time, you just open the flaps to put cabin air through. because there is coolant going through them all the time they are prone to clogging. also has there is no cabin air filter they are prone to clog on the air side as well.