The Yin
Member
Going to ask on here before taking it in for a checkup.
Veeery Loooong detailed story.
I’ve never had any heat issues with my 4Runner until last week. On a road trip and just about at my destination. Around 350 miles and 5.5 hours, driving from SoCal to Az. Outside temps from high 70s to low 90s. Had the AC running on low for most of the drive.
When I reached Kingman, AZ as I was pulling away from a stop light I happen to look down and notice my Temp gauge needle was dropping down from the top of the grey area back to the bottom edge. I’d never seen this needle higher than the bottom edge of the grey area. I immediately started to look for a parking lot to pull into, but at the next stop light the temp started to go up again, almost to the red mark. I pulled into a parking space and shut the engine off to let it starting cooling.
There was no smoke or steam, but my coolant overflow tank was completely full and had already spilled some coolant out into the engine bay. I let it cool for some time, and checked to find that the radiator was not full. (sidenote: I checked the day before hitting the road. At the time my car was on an inline, so the overflow tank was above the full mark, but the radiator was not 100% full. I assumed this was all because the truck was on an incline)
I took the truck a few blocks down to get some coolant at O'Reilly. I had my OBD2 reader connected to my phone to keep an eye on the temp and it got to just over 200 on the way to O'Reilly. I let it sit and cool while I tried to figure out what coolant I wanted to risk adding. There was no Toyota dealer to pickup the recommended coolant, so I got the Prestone 50/50 green.
I then went to eat some dinner (drove a few blocks to get there) and let it cool more before adding any coolant. It didn’t heat up to much on the way.
I did some research and was thinking the issue was that the system needed burping. I had just replaced the Radiator and hoses and few years ago when the truck was at 95K, it’s now at 120K. Did a full flush at the time and replaced with Toyota pink.
After it cooled my sister and I worked on adding some coolant and burping the system. It took about ¼ a gallon of coolant and there were some bubbles that came up. Also, the overflow tank was still nearly full.
We keep an eye on the temp as we finished the last leg of our drive, about 40 minutes on the road. It stayed around 186 to 190. The next day we checked and I was able to add a little more coolant. We drove another 1.5 hours to the campsite and it was still around 186-190, even when pushing 85 MPH.
Three days later after our camping I checked again and was able to add a little more coolant. Total added at this point was about 2/3 a gallon. Drove 2.5 hours, with normal temps. Used the truck some more that day with normal temps.
Next morning I checked and the radiator was still full. We drove home, without using the AC, but in 90 and 100 degree weather, and coming up thought the mountains on I-8. 350 miles, 5.5 hours and had a temp range of 186-192 the whole way.
So, should I take the truck to have it checked? I have no idea why it would have overheated the first time. Possible HG issue? Did I introduce air into the system by removing the Rad cap when the truck was on an incline? Everything seems to be working normal for right now, but I don’t know what caused this or if anything else could be damaged. I couldn’t see any leaks near the hoses or water pump.
Buuuuut, I have been hearing the “waterfall” sound for the past year or so, on cold starts. No other HG failure signs otherwise.
Please and thank you for any advice.
Veeery Loooong detailed story.
I’ve never had any heat issues with my 4Runner until last week. On a road trip and just about at my destination. Around 350 miles and 5.5 hours, driving from SoCal to Az. Outside temps from high 70s to low 90s. Had the AC running on low for most of the drive.
When I reached Kingman, AZ as I was pulling away from a stop light I happen to look down and notice my Temp gauge needle was dropping down from the top of the grey area back to the bottom edge. I’d never seen this needle higher than the bottom edge of the grey area. I immediately started to look for a parking lot to pull into, but at the next stop light the temp started to go up again, almost to the red mark. I pulled into a parking space and shut the engine off to let it starting cooling.
There was no smoke or steam, but my coolant overflow tank was completely full and had already spilled some coolant out into the engine bay. I let it cool for some time, and checked to find that the radiator was not full. (sidenote: I checked the day before hitting the road. At the time my car was on an inline, so the overflow tank was above the full mark, but the radiator was not 100% full. I assumed this was all because the truck was on an incline)
I took the truck a few blocks down to get some coolant at O'Reilly. I had my OBD2 reader connected to my phone to keep an eye on the temp and it got to just over 200 on the way to O'Reilly. I let it sit and cool while I tried to figure out what coolant I wanted to risk adding. There was no Toyota dealer to pickup the recommended coolant, so I got the Prestone 50/50 green.
I then went to eat some dinner (drove a few blocks to get there) and let it cool more before adding any coolant. It didn’t heat up to much on the way.
I did some research and was thinking the issue was that the system needed burping. I had just replaced the Radiator and hoses and few years ago when the truck was at 95K, it’s now at 120K. Did a full flush at the time and replaced with Toyota pink.
After it cooled my sister and I worked on adding some coolant and burping the system. It took about ¼ a gallon of coolant and there were some bubbles that came up. Also, the overflow tank was still nearly full.
We keep an eye on the temp as we finished the last leg of our drive, about 40 minutes on the road. It stayed around 186 to 190. The next day we checked and I was able to add a little more coolant. We drove another 1.5 hours to the campsite and it was still around 186-190, even when pushing 85 MPH.
Three days later after our camping I checked again and was able to add a little more coolant. Total added at this point was about 2/3 a gallon. Drove 2.5 hours, with normal temps. Used the truck some more that day with normal temps.
Next morning I checked and the radiator was still full. We drove home, without using the AC, but in 90 and 100 degree weather, and coming up thought the mountains on I-8. 350 miles, 5.5 hours and had a temp range of 186-192 the whole way.
So, should I take the truck to have it checked? I have no idea why it would have overheated the first time. Possible HG issue? Did I introduce air into the system by removing the Rad cap when the truck was on an incline? Everything seems to be working normal for right now, but I don’t know what caused this or if anything else could be damaged. I couldn’t see any leaks near the hoses or water pump.
Buuuuut, I have been hearing the “waterfall” sound for the past year or so, on cold starts. No other HG failure signs otherwise.
Please and thank you for any advice.
