No heat when car idles

Air pocket , start with the simple , inexpensive things first

Yep air pocket in the cooling system.

Guys the water pumps been fully replaced n radiator n cap alrdy it's not Any of that thermostats been replaced also how can I tell if it's air locked ?

How can i do a flow test on the water pump?

It’s not air locked or it would overheat. It has an air pocket inside the heater core, on difficult cases I’ve had to lift the nose of the vehicle two feet and keep pouring coolant into it every time a bubble shows up. Now this has to start out with a cold engine and radiator cap off, then start it and just let it idle. Unfortunately you have one of the hard ones to get it all out. If you still can’t get it, then any good independent shop will have a machine that can force the air pocket out.

Answer not posting

If Hyundai did the work then they didn’t do it right. Take it back to them, it obvious they didn’t finish the job correctly.

Again answer not posting

It's been a few months so I'll have to see if they'll do it if not can I get a vaccum pump to suck the air out?

Be careful with a vacuum pump as you could damage hoses, plastic fittings plus boiling away water in the system.

Ok so would it be easier to empty the system completely? N try doing it that way instead ?

If you are going to do that then make sure the nose is elevated first and possibly a little more on the radiator cap side. Then start the refil operation.

I just thought of something else you should check first and that is test for a blown head gasket. A DIY kit can be at your local parts store.

If the head gasket was blown wouldn't it bubble?

So drain the car elevated should I warm it up first or drain it completely cold?

Cold. If it is just getting ready to let loose the seepage would be small so you would not see any bubbles. I had a car that did this all the time, it would slowly eat coolant until the heater quit working then you refill it, this went on for two years before it finally blew.

I haven't lost any coolant at all

If your absolutely sure then go ahead with the drain and fill.

Ima try draining it first see if it fixes it cause I'm not messing with the water pump I'll have to call n see if they'll do the work free since they did it

I also have another question I got a bank 1 lean code p0171 I've replaced maf sensor both bank 1 n bank 2 sensors the code comes n goes but it's the same code everytime replaced the fuel pump around 30k miles back all new spark plugs n wires brand new spark module

It also has a new cam phaser in it as well

Long term fuel stays stuck at 25% n short term is all over the place when I replaced bank 1 sensor long term was o short term was 30% now long term is back stuck to 25% n short term is way below or above the 5% requirement

Sounds l I’lle an internal vacuum leak

Vaccum leak that's what I suspected but I suspect it's very small for the light to come on n off I did buy a smoke machine to test this weekend I was also gonna replace all the rubber housings also

Hyundai is gonna look at the water pump free of charge so I just gotta find the vaccum leak thx for the help

That smoke machine will certainly help looking that.

Ty guys for helping car was air locked as for the lean code there saying my aftermarket k&n air filter is the cause which doesn't make sense its been on there for 3 years n it's now just starting to run lean

If the K&N was ever over oiled it could foul the ACT sensor, try cleaning it and the throttle body, clear the code and see if it comes back. If it does then you may need a live data scan to see just what is setting the code.

If u didn't read the quote its got new maf new throttle sensors new o2 sensors n all everything under the hood has all brand new parts sensors n maf isn't causing it there telling me.to put my stock air fitler back on for the code to go away

The code itself is a p0171 comes n goes every 200 miles right at 200 mile mark it'll stay drive another 200 miles it'll go away for another 200 miles my long term fuel locks out at 25% short term is all over the place Def more then the 5% recommend gap between the 2

I’m still suspicious of a vacuum leak