Hey Scotty, I've been having heater problems with my 05 Tucson for the past few years now. I had the thermostat replaced, heater core flushed twice (And once recently by myself) and yet the heater doesn't work for any longer than a couple of days. Every time I flush the cooling system, the heat works fine - until a few days later, it stops working again. I have about 255,000kms on the car, no rust - even though I live in Canada (apart from very minor surface rust that I fixed myself), I take really good care of my cars and this one is no different. But, winter driving in -30C weather is a PITA just relying on the heated seats just to keep you warm.
It runs and drives great. I get about 400kms on a full tank of gas, but I blame that mostly on my driving habits. And other than the heater giving me problems, I still get cold AC - without anything else giving me problems. The car was originally passed on from my father to me, he would've traded it in 2 years ago because of the heater problem - but the Hyundai dealer was only going to give him $1,000 for it even though the car is worth around $7,000 back then. He now owns a 2019 Elantra GT N - Line, with the 1.6L Turbo motor with the 6-speed manual. That car is fast.
We had the Tucson since it was brand new in 04, I've had it for about 3.5 years now. It's slowly becoming a project car to me since I'm building a supercharger kit for it. The tiburon had the same motor 2.7L V6, so swapping the aftermarket supercharger over (and tuning it) isn't that much of a problem for me.
But the only thing that's stumping me is the heater problem. I rather not tear apart the dashboard to fix whatever is broken in there...but I will if I have to...
Any ideas? Thanks
Check to see if there is a hot water diverter valve in the heater hose lines. When heater isn't working but on, is outlet heater hose on the firewall hot (at coolant temp)?
@hillbilly
? The pipe itself, the one going in and out of the firewall is warm to the touch...sometimes the heater works, sometimes it doesn't. I can bring the car through a car wash and somehow, the heater starts working again but stops working when the car is cooled down the next morning/day
Follow the heater hoses to other end...
With that said, not sure if this vehicle has the water diverter valve but I have fixed a lot of them on Honda's.
What we're trying to achieve is determine if hot water is going in and out of the heater core. On many vehicles there is a valve that stops this flow so the heater core doesn't get hot and heat the car when not turned on heat. Some vehicles use an air diverter to just keep air from flowing over the hot heater core.
So we want to check to insure hot water is going through the core first. Check heater hoses when heater is working properly and car at temp. You shouldn't be able to hold the heater inlet hose long... the outlet should be cooler and holdable (if fan speed inside on high thus transferring the heat from the water to the air). Now repeat this test when heater NOT working. If hoses are not the same (similiar) temp as before, the hot water is being diverted and not going into the heater core. This could be the diverter bad (or a sensor somewhere that is keeping the ecm from properly operating the diverter valve. )
Now, if the heater hoses are hot and you can determine hot water is flowing through them, then it's airflow in the inside airbox being diverted around the heater core and thus not getting warmed up. Both issues are common failures.
To have heat you need hot water flowing through core and airflow going through core. Those are the first things needing to be determined before we can head down the correct path to a solution.