car cooling system question

fishhead · #1 03/15/14, 09:25 AM

Lately I've noticed the cooling fan is running more than usual on my toyota corolla.

When I checked the coolant level it was below the top of the core so I bought some premix and filled it and the overflow reservoir. The overflow reservoir must be cracked because it all dripped out. I'll get a new one next week.

I drove it home which is about 20 miles. Then I drove back to town and shortly after I started I saw the temperature gauge suddenly drop to cold. After a mile I pulled over and let it idle. The temp gauge came back up to normal within a minute or two and has stayed there for at least 30 miles. The coolant level seems stable.

Now the questions.

Did that sudden drop in the temp gauge indicate an air bubble getting purged?

I have a 6 hour trip on Tuesday. Is there anything I need to be concerned about as far as the coolant system?

Hip_Shot_Hanna · #2 03/15/14, 10:53 AM

Temp guage dropping to zero usually means its no longer covered with water , it could have been a bubble of air in the system , and it may have purge taps on the heater hoses somewhere , if not make sure the heater is on hot when you fill the system and make sure the heater blows hot , if not it has air in it , if it does it again stop and check the water level , ( be careful not to get scalded !!!!!)

fishhead · #3 03/15/14, 05:36 PM

That's another thing that I noticed. The heater air seems hotter now. I drove it again today and the gauge acted normally.

nosqrls · #4 03/15/14, 08:17 PM

It may have pushed the air out of heater core. check hoses to overflow tank it may be split and that is where your water is going.

fishhead · #5 03/15/14, 10:08 PM

My overflow tank is cracked and doesn't hold fluid.

If the engine doesn't get overheat does the fluid still flow to the overflow tank? I've never seen the gauge register anything over normal.

It's been so cold this winter I probably could have run the engine without any coolant flow. Those little engines seem to run cold. I once drove my Mercury Lynx with a broken water pump for 20 miles. The needle spiked for a few seconds but then dropped back to normal. It was 30 degrees that day.

topofmountain · #6 03/19/14, 03:13 PM

Quote:

Originally Posted by fishhead

My overflow tank is cracked and doesn't hold fluid.

If the engine doesn't get overheat does the fluid still flow to the overflow tank? I've never seen the gauge register anything over normal.

It's been so cold this winter I probably could have run the engine without any coolant flow. Those little engines seem to run cold. I once drove my Mercury Lynx with a broken water pump for 20 miles. The needle spiked for a few seconds but then dropped back to normal. It was 30 degrees that day.

Get that fixed ASAP. Not a smart idea to run any water cooled engine with out fluid no mater how cold it is. I've seen engines burn up in -25 degrees with no antifreeze.

I was a field mechanic in my younger days in Northern Nevada in the 70s that part of the Country got cold winters every winter. I remember two months every year of negative 0 temps at nights, with blistering 20-30 above during the days, then add wind of 10-40 mph with snow & it was cozy.
The weather was so bad sometimes we would build a plywood around the equipment we were working on with a salamander burning full bore. to keep the tools from sticking to your skin. We didn't have all these fancy mechanics gloves, we had cotton gloves what got in the way most of the time.
I love hearing all you guys complain about the weather this year. This use to be the normal back in the day. I remember my dad talking about the Great Lakes being froze over every winter back in the 20s He was raised in Wisconsin. After going in the Military WWII. He never went back & hated the Mid-west cold.