High Temp Measurement - How hot is the danger zone

[BrianSD_42]

So I recently fixed my high coolant temp issue but after refilling the coolant I didn't put enough in and it started to overheat (via scanguage) up to 220 and I turned it off, troubleshooted and then it heated up to 227 F then I turned the car off. I ran at that temp for 2 minutes tops. Finally after putting full amount of coolant and troubleshooting air pockets it is running normal now at 185-195 with AC & load.

My question is why doesnt the dash temp gauge BEGIN TO show hot until past ~130F ? ... (source some thread on T4R)

My dash never showed hot (or even warm). Only the scan gauge showed the temps. The dash gauge is functional, perhaps I was just not hot enough to trigger it.

Now that the AIR pockets have been properly burped - The truck runs great though. Just finished a wheeling, camping trip this weekend. As I said above - it now maxes out 195F with AC on full and driving up a mountain. Sitting idle or cruising is around 188-190. Even on the trails it was idling at 188.

:bat:

 

[THatfield]

I've heard that the dash gauge is pretty much an idiot gauge. By the time it reads too hot it's almost too late. Similar to the A/T Oil Temp light. By the time that thing comes on, you're in trouble.

Glad you caught it early and were able to correct the problem before damage was done. Especially since I know you just did head gaskets a couple thousand miles ago!

 

[ajonesnv]

I do believe there is only one person to ask, but I don't think Kenny Loggins is on this board!

 

[BrianSD_42]

Danger Zone !!!!!!!


<iframe width="853" height="480" src="//www.youtube.com/embed/NtHrS-w2H6E" frameborder="0" allowfullscreen></iframe>

 

[ajonesnv]

Danger Zone !!!!!!!

BAHAHAHAHAHAHA, Sorry it was the only thing that crossed my mind when I read the title.

 

[BrianSD_42]

But in all seriousness if anyone has an answer I'd appreciate it!

 

[amalik]

185-195... you're lucky. According to Torque Pro, my coolant temps are around 200-210 degrees after driving for just a few minutes.

 

[4Running Daily]

But in all seriousness if anyone has an answer I'd appreciate it!

So as we all know, I've had plenty of experience overheating these 3.4l engines. Never once out of all 3 head gasket failures did the gauge read above normal. The highest I've seen my scan gauge was 227 and the temp gauge never moved. I truly believe this gauge is worthless.

 

[cyclops13]

185-195... you're lucky. According to Torque Pro, my coolant temps are around 200-210 degrees after driving for just a few minutes.

Even mine stays around 203 within a few minutes ride. Need to check on longer trips.

 

[BrianSD_42]

185-195... you're lucky. According to Torque Pro, my coolant temps are around 200-210 degrees after driving for just a few minutes.

Air in the system.

The only thing that's changed in the last two weeks is my mechanic finally properly bumped the air out of the system. It was running at 198-202 consistently around San Diego for about two months but now it's fixed.

 

[4Running Daily]

Air in the system.

The only thing that's changed in the last two weeks is my mechanic finally properly bumped the air out of the system. It was running at 198-202 consistently around San Diego for about two months but now it's fixed.

Can I suggest a guy that actually does decent work, not The Truck Shop?

It's a tad far from you, but Service Pros in San Marcos does shit right the first time.

Service Pros Automotive: San Marcos, CA: Engine & Brake Repair, Oil Changes

Jeff is a one man show, but he gets the job done right.

 

[BrianSD_42]

I'm all ears.

The business you mention, Is that who did your heads twice?

Just to be clear mine didn't get to 220 & 227 BC of Truck Shop. When I left there it was at 195-202 around town and on freeway for months. It only got hot after I drained and filled and tried to re burp it myself.

Once it was not (well much more than normal) then I shut off the truck and let it cool. The guage never moved above the middle although it is working. I believe that 227 wasn't hot enough to warp anything but it still isn't good.

 

[amalik]

Air in the system.

The only thing that's changed in the last two weeks is my mechanic finally properly bumped the air out of the system. It was running at 198-202 consistently around San Diego for about two months but now it's fixed.

My last coolant flush was done by one of the local Toyota dealers themselves. I paid for a full system flush vs a drain'n'fill on my own.

So, if my temp is higher than it should be due to air in the system, they themselves didn't burp it completely. Not very hard to imagine that scenario; we all know dealers are not perfect.

I'm not too many miles away from new coolant though, and I'll do the next drain'n'fill/burp myself -- so I'm not too worried.

 

[nevada]

So I recently fixed my high coolant temp issue but after refilling the coolant I didn't put enough in and it started to overheat (via scanguage) up to 220 and I turned it off, troubleshooted and then it heated up to 227 F then I turned the car off. I ran at that temp for 2 minutes tops. Finally after putting full amount of coolant and troubleshooting air pockets it is running normal now at 185-195 with AC & load.

My question is why doesnt the dash temp gauge BEGIN TO show hot until past ~130F ? ... (source some thread on T4R)

My dash never showed hot (or even warm). Only the scan gauge showed the temps. The dash gauge is functional, perhaps I was just not hot enough to trigger it.

The truck runs great though. Just finished a wheeling, camping trip this weekend. As I said above - it now maxes out 195F with AC on full and driving up a mountain. Sitting idle or cruising is around 188-190.

:bat:

while its not a 3rd gen...

my 85 truck was originally a 22r, I have since swapped in a v8. just a few weeks ago I got the correct bushing to hook up the factory temp sensor, so the in dash gauge would work. I also have a mechanical aftermarket gauge.

when the mechanical gauge was reading "normal" just slightly over 190, the stock gauge was BARELY reading up off cold. I cant even imagine how hot it would have to get for the stock gauge to read in the normal spot.
I think Toyotas just run HOT.

 

[4Running Daily]

I'm all ears.

The business you mention, Is that who did your heads twice?

Just to be clear mine didn't get to 220 & 227 BC of Truck Shop. When I left there it was at 195-202 around town and on freeway for months. It only got hot after I drained and filled and tried to re burp it myself.

Once it was not (well much more than normal) then I shut off the truck and let it cool. The guage never moved above the middle although it is working. I believe that 227 wasn't hot enough to warp anything but it still isn't good.

No the shop that did my heads twice and failed epically is called
Rollies Automotive
Rollie's Automotive - Home
Avoid these guys at all cost.

The place I mentioned above, Service Pros, is the place that did my engine swap in July and he's done a few other jobs for me. He's the guy most of the FJ guys we wheel with go to.

 

[twitchee2]

FWIW, Before I pulled my efan system out, I accidentally knocked the off switch with my knee. I sat idling at a gas station for a couple of minutes and it started to steam a little. Scan gauge read 248, needle was in the red. Shut it down got the fan on and it was fine. This was 3 yrs ago. Not saying it was good for it but I have not noticed any issues from it.

My dash gauge starts to go up around 210-215, I had a very poor coolant mixture not letting the heat get out.

 

[LittleCaesar]

Stock mechanical gauges suck for the most part; the most accurate ones I have encountered are used on Chevy trucks. I think it is mostly a comfort reading for most drivers, showing them that their automobiles are cooling just fine. If instead of H on the gauge it read " you will cause severe engine damage if the needle gets this high" most drivers would be much more nervous in driving their automobiles. Maybe paranoid.

One car a worker just got a Nissan GT-R and it has more gauges than an airline cockpit. It even reads tranny pressure. For a normal automobile such detail is overkill. However, with more digital readouts in autos today, more live sensor data can be monitored by the driver.

I burp my cooling system by filling the radiator with a gallon of antifreeze. Then squeeze the lower radiator hose to get any lodged pockets of air in the hose. Then fill the radiator,squeeze the upper and refill until no more bubbles are present. Start the automobile, and with the radiator cap off, turn on the heat to max for about 5 to 7 minutes. Such has worked well for me for the last fifteen years.

 

[BrianSD_42]

I sat idling at a gas station for a couple of minutes and it started to steam a little. Scan gauge read 248, needle was in the red. Shut it down got the fan on and it was fine. This was 3 yrs ago.

This is, for me, the most reassuring comment so far.

 

[twitchee2]

This is, for me, the most reassuring comment so far.

Brian, that was actually about 2-3 mo after I blew up my fan on that big bear trip. So when ever that was. Might have actually ben almost 4 yrs ago now.

 

[4RunnerChaos]

This is, for me, the most reassuring comment so far.

I changed my radiator after an accident started up a hill, my mechanical gauge went as high as it could and I made it 3 blocks back. I have noticed any problems so far. It happened about 10k miles ago. Just had to keep filling and driving it a block or so until it worked out the bubbles. I don't have a scan gauge or anything just what the truck came with.