That answer is all over the forum. Get a beer, put on some U2, and have a go at some research.

 

OK I have a question about my heater, It doesnt seem to want to warm up and when it does it works just ok in town but the minute I drive on the highway it blows cold air again. Could this be that I need to replace the thermastat for one with a higher temp. on it or could it be something not so simple.

 

Yes you need to replace the thermostat, yours is stuck open.

 

Or you're low on coolant. Had that happen a time or two as well.

 

If the above two don't work, flush the heater core. Worked like a charm on mine after eliminating the previous suggestions as causes.

 

I replaced the thermostat and now there's white smoke coming from engine my guess is coolant that was spilled from gasket from not draining it right what do y'all think?

 

If the smoke is coming up from the engine compartment then I would probably say yes it is just spill that needs to burn off and it should be fine. But if you are talking about out the tailpipe then thats a little more complicated.

 

I just washed off the excess coolant off the engine compartment and it's doing fine I'm finally getting hot air. Thanks for all the help D. F!

 

!!!code p0304!!! Cylinder 4 misfire what are causes and possible solutions

 

I get that same one when its really cold and I let it idle for 10 min. or so to warm up. It only comes up a couple of times a year so I personally don't worry about it, just clear it and go. If it is persistent check the condition of the regular tune up parts cap, rotor, plugs & filters maybe try some injector cleaner.