Vehicle Temp [Archive] - Forum


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12-08-2009, 06:41 PM
Yes, I've already searched, but no one seems to describe exactly whats going on with my car. Ever since last winter, the tempurature I get from my heater is about equal to the temp in the weather. For example... this morning, it was -2 when I went to start my car. I let it run for about 15 minutes, then drive to work. When I first start driving, the temp has gotten to about 150, but when I get about 3 miles down the road in this cold, it literally gets back down to like 100-110, and the air coming in the car isn't that warm anymore. Do I just need a new thermostat?

Also, if this has anything to do with it; I get a Low Coolant light about every 2 weeks and have to top it off.

Any help would be awesome.

Sorry if this has been covered to death and I just didn't find it in my search.

12-09-2009, 02:55 AM
Do you know where your car is leaking coolant? Even with my leaky water pump, i don't top my system off every two weeks.

Don't know how to help you with the heat. The lowest my car and wagon seen was about 20f. Heat worked well in both.

12-09-2009, 05:05 AM
Having to top off coolant could be a sign of your LIM gasket going out. As rocketfast said, see if you can locate the source of the leak. Sometimes the LIM leaks outside the engine and sometimes it leaks coolant into the engine. The former is not too bad but is much less critical than if it leaks into your oil and causes your engine to seize up.

Check your oil for milkyness. If you pull your dipstick out and it still looks like oil and you can light it on fire with a match without it hissing and poping then your oil has no coolant in it. If you light it and it hisses, pops, crackles, wont light then stop driving the car because the contaminated oil is eating your bearings. Dont even drive it to a shop, have it towed or do the work yourself. It should be noted that this time of year it is common for you to have whitish goo on your oil fill cap due to condensation from the hot/cold cycles of the engine and moisture in the air. Long trips will burn this off, but I dunno about a car that wont heat up all the way. You will probably see a lot. This is why you should pull the dipstick to check the quality of the oil.

Another way to test if you have an outward leak is to hose the engine bay down really well and add a universal UV dye to the coolant. Drive around a few days (if the oil is ok) and shine a blacklight or LED light in the engine bay. Anything that glows is where you have a leak.


I would however suspect a faulty thermostat for the heat issue. Changing it is a small PITA so hopefully you have someplace warm to park it while you do the work (or have a shop do it).

It might also be beneficial to change the pressure cap on the coolant tank. If the seal is bad it might not be holding pressure and allowing the expanding (hot) coolant to just run out the overflow hose. Never tighten the cap more than the average female could undo. Any more than this will ruin the delicate gasket.

Also, any time the coolant falls below the bottom of the coolant tank the system must be purged of air. In front of the UIM with 3400 stamped on it you will see a long black tube with a tower on the left. On top of that tower is a screw. It is made of brass and very delicate so when you turn it be careful you dont round off the edges. With the car running and up to temp slowly open the screw until no air comes out and you have a steady stream of coolant. Once you are sure there is no more air tighten the screw back up and you are all set.

12-09-2009, 12:52 PM
Since you mentioned the coolant leak it sounds like you've got air trapped in your heater core. It also sounds like your thermostat may be stuck open.

If the leak is coming from your lower intake manifold gaskets, replace the thermostat while you've got the manifold out. Its a hell of alot easier.