R34 Gtt Heater Problems

[d.matho]

Hey guys, Ive googled for hours and tried the a/c system diagnostics and have got anything.

My heater is only blowing cold air, no matter what temp its on its freezing, I've checked the passenger side footwell, theres no leaking and no gas or steam coming from any of the vents to indicate busted heater core, both heater hoses are warm it, not cold but not too hot to grab hold off. I'm pretty sure r34's use an internal heater tap as I can't find anything at all on the heater system for them, even in the manual, only thing I can think of is that there might be an air bubble in the system but I bled it till there were no air bubbles escaping.

so im stuck, anyone got any ideas on what it might be?

[Sinista32]

broken thermistor ?

heater tap was another guess

receiver dryer ?

Best to take it in and see if they can pull a code otherwise it'll be guess work till you stumble over the issue

Edited May 7, 2015 by Sinista32

[scotty nm35]

Blocked heater core? Is the coolant brown?

I have unblocked a few heater cores lately without removing them, using water and vinegar in the rad.

[Scott Black]

They don't run heater taps anymore, they have flaps that direct air.onto or away from the heater core. Climate control might have an issue with temp sensors, or a blend door motor might be broken

[d.matho]

how would I be able to tell if it was the thermistor?

yeah I was thinking it could be a blocked core and the coolant is brown, so maybe thats the next thing I try. I was thinking of trying to un plug the heater hoses and reverse flush the heater core at low pressure. how do you do it with water and vinegar?

Ive taken the dash cluster off to check if all the sensors were plugged in, as far as I know theres just one on the drivers side behind a little plastic grill thing. Does anyone know how to get to the blend door? Im pretty sure I can hear it moving when I swtch the temp control from cold to hot but its probably a good idea to double check its moving, does resetting the actuator for it in the diagnostics mode do much?

[scotty nm35]

I flushed the system as best I could, a few times. Then I filled it 50/50 with water and white vinegar. Took a few days, driving the car, but it came good. I wouldn't leave it in there much longer though.

It will clean up all the rust in the system, but it will also need a damn good flush after. You don't want the crap going through your radiator either, so an inline filter in the top hose is the go, even if it's just a stocking slid over the hose fitting.

[d.matho]

I might give it a go, when i bought it the car had been sitting for ages and had a cracked top tank. I got the radiator reconditioned and it works great now, but yeah there could be heaps of rust and crap in the pipes. is it worth replacing all the hoses with new silicon ones after a flush?