Overheating problem?

[bex]

I was stuck in traffic the other day for a long time; I eventually shut off my explorer to wait. The traffic started to move and I started it up and it went fine for a minute until a bell sounded and it stated "reduced power mode" on the display, and the temp was pegged in the red.

I pulled quickly into a gas station and shut it off. I let it sit for a few minutes then turned the accessory on and it showed the temp as normal. I decided it might be a fluke and started it up and drove another couple of minutes and the same thing happened again.

As a note, the temp goes from normal to red in a flash, no slow movement or anything.

I let it sit at the gas station for awhile until it cooled (even though accessory position showed normal temp). I opened up the water reservoir and poured a gallon of water into it. I started it up and it did normal for quite a few minutes (15 about), back home, even sitting at two red lights just fine. The next day I poured another gallon of water into it to the fill line; I have not driven the explorer since.

I have read many useful threads on the issue, but I am pondering this question; could it have gotten hot because it was 2 gallons low on water? And sitting in traffic, the explorer did not have time to cool off the hot water because there was not enough water in the system? So when I turned it back on, the explorer circulated the still hot water back into the motor, causing the problem?

I am wondering if this is possible, if not then the thermostat is most likely the problem.

It was low on water because it has this slow mysterious leak and I totally forgot for a while to fill it up again.

Weather is warm S. FL., the explorer is a 2003 4.6 with 98k miles on it.

Thanks!

 

[matt0248]

Yes, it definately could have been because it was low on coolant, 2 gallons is significant. Has anyone looked for this coolant leak? Have you had a block test done to check for combustion gasses in the coolant?

 

[bex]

I have looked myself for it, I cannot find anything. It leaks I would guess about 3/4 gallon a month, no matter how much driving I do.

I should get some professional tests done, but no money for it right now. The oil changes are good, so I put aside my immediate worries. It has been leaking water for a long time, 2 years about, maybe even longer but I bought it used so I do not know.

The block test is something I should schedule, that way I can get an idea if it is something serious or not, and then get rid of it if it is.

I am driving it tonight to get something, about a 45 minute roundtrip, will see how it does. I hate driving with being paranoid that something may occur!

 

[bex]

Ok, drove it today for about an hour, sat in traffic also. The explorer fine, as normal. I did not smell any coolant or anything. I am really hoping it was something as simple as not having enough water in the system.

Thanks for the assistance!

 

[skeeter123]

Water isn't coolant. If you continually replace leaked coolant with water, pretty soon you have pure water in your system, not coolant. Water will boil over much quicker than coolant. I like to use the 50/50 pre-mix stuff to top off the reservoir, since its already mixed and they use distilled water, not the tap water with all the calcium/mineral crud in it.
It sounds like you should do a complete drain and refill to make sure you have at least a 50/50 mix of anti-freeze and water. But first you need to find the leak. Some of the parts stores will lend/loan you a pressure tester (or you buy it and they give you your money back when you return it). You can pump up the system and see if you can find the leak.
Hope this helps.