Anovice

I have never had a problem with the heater, including driving to work yesterday in 25 degree temperatures. However, driving home the heater acted up. The car was warm for about 10 minutes with the temperature guage right in the middle, it's ususal position. Always by this point, the heat comes on, in the automatic position, with the fan mode blowing the hot air to the floor. Nothing this time. I changed the mode position to the vents/windshield (far right mode) and the fan went on high. In this process, it took the system off automatic and it went to manual. I felt heat for a few minutes, but then the air went cold.

Last night I took the car out again and noticed a few more things:

1. The fan/heat in fact will not go on when the controls are in the automatic position, even when the engine is fully warm. This never happened before. When I change the mode, for example from the floor to the vents/windshield, the system goes from automatic to manual and the fan/heat kick on.

2. After a few minutes on, the heat turns to cold air, back to warm air, back to cold and so on.

3. While this is happening, I noticed the temperature guage going from the normal middle position to hot. In fact, at one point it went up almost to the top and settled back down at 3/4 which is still 1/4 higher than it mormally rests. Obviously this is not normal is 20 degree temperatures.

A friend thought the problem may be the thermostat sticking. Maybe that is the problem, but what connection does that have to the fan and mode position? If you suspect the thermostat, I have two questions. Can I go to any local local parts supply place and purchase one or is it better to go to the local Toyota place for the part? And, what does it entail to change it?

So, I have a problem, which not only includes the inability to keep the interior of my car warm, but also difficult to keep it from over heating. Even though I know little to nothing about cars, hopefully with your suggestions and a friends help, we can make a few attempts to fix the problem over the weekend. If not, hopefully I can make it to the shop on Monday without the car over heating or me freezing! Thanks much, Anovice

amf1932

Did you make sure that the coolant level is up to the top of the radiator, and the overflow tank is about ½ full? I mention this because if it's not, strange things like this can happen.

Anovice

Thanks for your post. I will be able to check tomorrow morning and re-post. In one way I hope that is not the problem as approimately one month ago I needed to add some liquid (I added straight anti-freeze) to the overflow tank. As I remember, it was a little less than a quart. If it is low again, that may be pointing to another problem.

Come to think of it, at that time I did not check the radiator and only filled the overflow tank to about 1/2 thinking that was sufficient. I assume I can take the radiator cap off when the engine is cold.

amf1932

You should never add straight anti-freeze to the overflow tank! It should be diluted to 50% water and 50% anti-freeze!
P.S. Yes, you can take off the radiator cap when the engine is cold. Also, if you find that the coolant is low, then add a 50-50 mix and fill it up to the top of the radiator. I also suggest that you also mix the coolant in the overflow bottle to the same dilution.

Anovice

I took the cap off the radiator and fluid is not covering the top of the fins. Also, being I cannot see the level, I do not know how low it is. Regarding the overflow, that too is low, however, I can see about 1" of fluid at the bottom.

I have anti-freeze, but it is 100% anti-freeze and not diluted. Some one told me to distill the water to reduce the mineral content, which I am in the process of doing.

Tomorrow morning I will mix 50/50 water and anti-freeze and first add it to the radiator. When it fills up, I will add to the overflow to make sure it is 1/2 full. The only question I have is after I add to the radiator should I start the car to allow it to circulate BEFORE adding to the overflow OR add to both prior to starting the car?

amf1932

Firstly, make sure that the type of anti-freeze that you're using is the proper type(Red or Green). Than dilute it 50% anti-freeze, 50% water.
Add this to the top of the radiator and close the cap. Than fill the overflow bottle to the full mark(about halfway up).
Start the engine and let it warm up to operating temperature. Turn on your heater so the coolant also circulates through the heater coils.
Turn off the engine and let it cool a bit(about 15 minutes), than take off the radiator cap to check if the level is still up to the top and the oveflow bottle has the proper amount of coolant. If not, add more coolant and do the above procedure once again. That's it. Good luck, and let me know how you made out.

Anovice

You raise an interesting point.

Approximately 1 year ago, I needed my radiator replaced. I took it to the local mechanic, where I always go. Normally, I buy all parts on line and he supplies labor. In this case I remember he purchased the radiator as I could not get one in time. What I do not recall, is did I buy the anti-freeze. Something tells me I went to the local Toyota dealership and purchased the anti-freeze and that it was red in color. I will need (or maybe not depending on what you say) to look for the receipt, which hopefully I can locate. What I DO KNOW is that my owners manual does not specify red or green and only says the type (I am elsewhere and do not have the manual with me), which is exactly what I purchased. In the morning I will double check that the type, regardless of the color matches between the owners manual and the container of anti-freeze.

Up to about a month ago I did not have to add any fluid. As mentioned, then I had to add some. I am now wondering if I caused a problem.

Assuming the type (I want to say ethylene glycol) is what the owners manual calls for and is the type in the container. Should I go a head and add a 50/50 mixture, REGARDLESS of color, or be safe and just add water. Below is a 'definition' of antifreeze, which as I read it does not differentiate between color...red or green. Pleae let me know what you think I should do, assuming my owners manual only specifies type (ethylene glycol).


Definition: Antifreeze protects the cooling system against both freezing and boiling over. When used at normal strength (50% antifreeze, 50% water), it can lower the freezing point of the coolant to -34 degrees F. and raise its boiling temperature to 276 degrees F. Never use straight antifreeze in a cooling system. Always mix it with at least 50% water. Most antifreeze is 95% ethylene glycol (EG). The only differences between brands of antifreeze are the type and/or quantity of anti-corrosion additives used. Ethylene glycol never wears out but the corrosion inhibitors do. That's why antifreeze should be changed every two years (except for long life antifreezes, which have special additive packages that allow them to go up to 5 years/150,000 miles between changes). For the environmentally concerned, propylene glycol (PG) antifreeze is also available at slightly higher cost. PG antifreeze is less toxic than ethylene glycol

amf1932

If your cooling system had green anti-freeze....continue adding green, and if it had red.....continue adding red.
Read this and it'll get you a little crazy. http://autorepair.about.com/cs/produ.../aa052601a.htm

Anovice

So far your diagnosis is right on!

This morning I first added a 50/50 mixture to the radiator. I was rather surprised, as it took between 1-1/2 quarts. I then added about 4oz. to the overflow. Per your instructions I then ran the engine to operating temperature and turned on the heat. Unlike Friday, after the car warmed up for a few minutes the heat came on in the automatic mode and blowing to the floor. I then turned the car off and let it cool down for 15 minutes. I re-checked the radiator and needed to add about another 4-8oz. I topped off the overflow. I then drove the car for about 20 minutes both with the heat on and off. The temperature guage stayed right in the middle. All looks good. While it is in the mid 30's and about 10 degrees warmer than Friday, I would not think that would have made any difference.

I checked my records and saw that I had the thermostat, water pump, "tentioner", etc. changed in January 2005. It has been 2 years and in this period I do not recall adding any fluid to the radiator. I am wondering if it is normal to need to add this quantity of fluid after a 2 year period.

I called the mechanic and cancelled the appointment for this morning. I will re-check the radiator later today and again at the end of the week. If I do not have to add more fluid, I will assume all is good. If I do have to add, I will bring the car in for a 'pressure check'.

Thanks for all your help and if you think there is something further I need to do at this point, please let me know.

amf1932

Great!
At this point the only thing I can think of is to make sure the overflow bottle has the proper amount of coolant. There should be a low/high marking inscribed on the bottle. All you have to do is to pop open your hood and glance at the level, and if you see it dropped over a period of time then you most likely have a slow leak somewhere. The pressure check is a good idea.

Anovice

Just out of curiosity, why only check the overflow bottle now and not the radiator too?

If I would have only looked at the overflow bottle the other day, I would have seen about 1" of fluid at the bottom of the bottle and while clearly below the line, I would have never thought the radiator would have been as low as it was.

Could not the same thing happen again?

amf1932

The overflow system requires that everything is in balance. By this I mean, if at one point you opened the radiator cap to check the level, and it wasn't up to the top of the radiator, and then closed the cap you have lost the siphoning action that's needed to pull the coolant from the overflow bottle into the radiator. Therefore, it's necessary to keep a level of coolant in the overflow bottle. Generally, you should be able to check this by viewing the overflow bottle fluid level and see if it changes from a cold engine to a hot engine....the level should rise due to expansion of the heated coolant and engine parts. It shouldn't be necessary to open the radiator cap to check the level.