So, my Dad was driving my 98 LX up to the garage for a brake job, and he was saying that once the air got warm inside of the car, the vent's started spewing out cold air and then warm again. It continued for minute hot, minute cold. By hot I mean enough to notice it was warm, but not overly hot.

Now this might be a little bit of a issue because I do live in Newfoundland, Canada and our winters are usually around -20(celcius) and I need to have a heater to keep the windows clear. My question is could this be the thermostat causing this problem or the heating element or a combo of both or am I completely missing what's wrong? Any suggustions?

Any and all help is greatly appreaciated!
Zack

 

My guess is that the coolant is low and that air is trapped in the system. Top off the reservoir and radiator and then bleed the cooling system (=push dash lever to full heat, put the radiator cap on loosely, let the engine idle until the radiator fan turns on at least twice, and top off coolant again in radiator).

 

Ok. I'll give that a try if I get it back from the garage tonight and let you know.

EDIT: Should I turn on full as well as the heat? I'm assuming yes.

 

I agree with Ron. Intermittent heat is a symptom of low coolant level. Check that first. If that's not it it could be the thermostat. A bad thermostat will also cause the temperature gauge on the dash to go up and down.

Park the car facing uphill if you can (so the radiator is the highest point, and air bubbles will tend to go there.). Wait for the engine to be completely cold before removing the radiator cap. Don't just check the level in the bottle. If you have coolant in the bottle but the radiator is not completely full, replace the radiator cap. It controls the flow between the radiator and bottle.

 

The blower does not need to be running. It's only important to have the heater lever/dial setting to the max heat position.

 

although for testing purposes to see if the procedure is working, turning on the blower would be a useful test though not at the highest setting.

 

I was talking to the mechanic a hour or 2 ago. He said that the coolant was running pretty low and top her up should fix it.

When I asked about the blower, I prob. should have been a little more specific, haha. Should I turn it on say 1 or 2 while I'm waiting for the radar light to turn on, or wait until it has flashed?

Also, should I wait until the car cools down before I top it off because theoretically speaking, wouldn't I get burned if any of it splashed up or is the car not going to be running long enough for it to get that hot?

 

The bleeding process does not require the blower to run. It also won't hurt to have it on during the procedure.

The bleeding procedure is done with the radiator cap loose, so the system cannot pressurize. Therefore, at the end of the procedure, you should be safe to remove the loose cap and top off the coolant when the engine is hot.

 

Perfect! I'll keep you guys informed. Looks like it'll be wedensday before I can do it. School and work tomorrow...and I just want's to drive tomorrow night so **** that.

 

It's good to have the garage do it, because you risk engine damage by driving at all with the coolant so low the heater doesn't work.

What I usually do for bleeding is fill the radiator completely with the engine cold, then start the engine with the cap off. The level will probably drop immediately, so pour more into the radiator while the engine is running. Keep an eye on it and top off again if necessary. As the engine warms up, the radiator should start to overflow. Put the cap on then and leave it alone (heat and pressure are building, so it will be dangerous to remove it). Make sure there is coolant in the bottle. Let the engine fully warm up and watch that it doesn't overheat. You should be good to go at that point.

When you are seriously low on coolant that means it has leaked out somewhere, so look for the leak.