It hasn't gotten steamy hot but today when I shut the engine off I heard it gurgle and since it has been showing significantly hotter than normal on the gauge, I suspected the noise may have been the water boiling. I flipped the switch back on and sure enough the gauge climbed to the top of the red zone. Yes it was 103 and I did just get off the freeway 7--8 minutes before this after driving 70 mph for 20 miles with the AC on. But it shouldn't be getting this hot. I checked the fluid and it is full to the top. The overflow is just a little below for full "hot". Can someone suggest other things to check? Much obliged.
Bad radiator pressure cap, bad thermostat, improper coolant mixture, loose water pump belt, radiator partially plugged, radiator-a/c condenser covered with debris, bad head gasket.
103 is pretty hot and it you shut down right after a high speed cruise the engine temp has not stabized yet and it will get hotter before it gets cooler. After a hard run on a hot day, shut of A/C and let it idle for a minute or two to stabilze engine temp then shut it down. BTW, improper coolant mixture is not the cause of this even though some maintain that greater than 50% anitfreeze is bad (it is not). You might check to see if radiator cores stack is plugged with bugs and grit too.
I live in Phoenix and it is normally that hot in the summer. Check to make sure the radiator is full up. To do this you have to wait for the engine to be dead cold. Take off the radiator cap and make sure the radiator fluid is full up to the top of the radiator. If there is a lot of air in there, it has trouble pulling additional fluid from the overflow tank. Inspect the radiator cap. There are two rubber gaskets, make sure neither are torn or missing.
Gurgling is not good but you've already received some good advice regarding cool down of the engine before turning it off. Watch your temperature gauge closely. From a cold start it should rise slowly and stop just short of halfway to hot. With the A/C on it may run a little hotter. Any jerkiness or temperature swings hot to cold means coolant system maintenance time. My first step would be a new OEM thermostat. If you haven't already changed out the coolant, it is overdue.
Keep up informed on what you find. I've got the '99 Tacoma maintenance manual electronically if you need to see any sections. Paul.
Today I drove the truck about 200 miles on mostly interstate highways and Sate highways so I've got some more symptoms to share. This morning before it got above 95 degrees, I was already seeing engine temps pushing up towards the red zone. It did actually crawl into the lower portion of the hot zone for a minute or two. Speed was low 60's and dropping to see if this would cool the engine down a bit. I pulled over to the side of the road and dropped the tail gate to reduce wind drag. As I began to come back up to speed, I noticed the engine temp had actually increased after I started an easy acceleration. I turned off the AC and brought the speed up to 55. The temp began dropping. At this point the thought of inadequate air flow through the radiator seemed like a possibility. The temp settled at about 7/8ths of the way to hot. Occasionnally it would rise a little and fall a little but never rising to the red area and never falling below the 7/8ths level. While the temp had come down a little, I was concerned enough to stop and check the raditor level at a gas station. I ran water over the entire radiator for a couple of minutes. I was inspecting the radiator for excessive bug accumalatons that might block air flow but this doesn't seem to be the case. I noted the temp gauge was still about 3/4 to hot. Cap felt only warm to the touch. I eased off the pressure. Nothing. I went ahead and turned it a litte more and the spew startled me and the cap fell to the ground as I backed away. Spew stopped within 1 second. Only very minor steam was present. I began adding water slowly. No reactions. It probably accepted a pint and a half. I noticed there was practially zero flow. I put my finger in the "clear" water and it was only luke warm. With the water full to the top, I left the cap off and let the hood just click shut. I drop the short distance back to the Walmart where I had dropped my mom off and got out and checked the water again. Now it was bright green but still had very little flow. Engine temp gauge now showing about normal temperature. I continued on to my destination at about 60 mph with the temperature gauge indicating about 85 - 97% to hot. Later in the day when it was time to head off to a new destination which was about 70 miles away, and the temperature getting close to
100, I saw the same behavior. This time however, I paid attention to the temperature before it was abnormal. I was able to drive 20 miles or so with normal engine temperature and then it began to heat up. I think I may have had a strong tail wind and I was running in the upper 60's. I couldn't descibe the temp guage as being jerky. It is not like other thermostat problems I've seen where the engine would suddenly cool down and heat back up. The temp gague on the Tacoma moves slowly.
Paul, I'd like to take you up on your offer to share you manual. The section that describes the steps to change out the thermostat. While this is likely pretty simple and I've done a few American cars, I'd like to do it by the book if that's an option. I own two Toyotas ( my Tacoma and the wife's broom **) but havn't ever put a wrench on the engines. I sure can't say that about the '97 Honda Civic my son drives. Do you recommend the thermostat, gasket and sealent all come from Honda or some other suppliers? I agree it is time to change out the anti-freeze
Thanks guys, Lynn
** OK, It's really a 98 Avalon; not a broom.
The lack of water flow through the radiator would seem to suggest that the thermostat is not opening. Paul. wrote:
Definitely a problem there. Usually the cheapest start is to change out the thermostat. Most will recommend the Toyota thermostat and gasket. Do it while you are changing the antifreeze.
A hint when you start to overheat: turn the heat on inside the truck. That will flow some coolant through the heater and get rid of some of the engine heat. It is a lot more effective than dropping the tailgate of the truck. (Yes it is going to get hot fast inside the truck.)
And please don't take the radiator cap off the radiator while the engine is hot. A steam burn is very painful. Squeeze the upper radiator hose (the big one entering the top of the radiator). If it is firm or hard, the system is still under pressure and it is not safe to remove the radiator cap. If it is soft and cool, go ahead and slowly remove the cap but do not push down on it. It should turn about a quarter of a revolution and then stop. Then push down on the cap and turn it the rest of the way off.
MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.