Highway temp trouble (1 Viewer)

[saucebox]

I will also note that the coolant is the regular green color,

Shouldn't be. Should be the red or pink.

 

[Nightbrew]

Shouldn't be. Should be the red or pink.

I don’t want to debate what’s better. When replace it, it will be with oem fluid. However it’s what I inherited. Is there reason to believe that my temps might be a bit higher because of the green antifreeze vs red or pink? I don’t recall reading any posts that would indicate green would run at a different temp than red or pink. I am open to the info though. Thanks

 

[abuck99]

Not likely related to color or type- the Toyota SL or SLL doesnt cool or transfer heat any differently- enough that anyone would notice anyway. But age of coolant does impact additives and those diminish over time- loosing corrosion inhibitors, and lubricating properties(pump cavitation).

If the radiator is original- it will not cool as efficiently as a new one. Fins get bent and clogged, and build up in the lower internal passages start restrict optimal flow. I would try to clean radiator from back side- spraying water forward towards condenser, make sure theres no build up on the front side of rad, drain coolant: including block drains, flush system with distilled, then refill with new.

Also if you havent flushed your trans, you might do that as well- since it cycles through the lower tank adding a fair amount of heat.

If i temp swing really annoys you, spend $175 on a new radiator, and $60 on fluid and change it out. Its an easy job.

 

[SHIfTHEAD]

I did my timing belt last year at 240K, engine temps were one thing that made me want to go ahead and do it sooner than later. I bought the LX at 215K and couldn't confirm it was done at 180K as the sticker implied. I was having an issue with temps that would hover around 205 going down the road. I had a new radiator to install at the same time I did the timing belt as well.

When I did the job I found that the thermostat was dated 2004, so it would have been the original thermostat from the factory. Thinking little about it I changed it and finished the job. I new radiator, hoses, etc also went in and the problem went away. Suspecting it was the thermostat I tested it in boiling water to find it open only a couple millimeters when hot. I needed to do the job but realized if I had applied KISS methodology I could have swapped the thermostat and solve the issue without having to do the timing belt early, as I could tell the timing belt was good when I pulled it out. YMMV

 

[Nightbrew]

Not likely related to color or type- the Toyota SL or SLL doesnt cool or transfer heat any differently- enough that anyone would notice anyway. But age of coolant does impact additives and those diminish over time- loosing corrosion inhibitors, and lubricating properties(pump cavitation).

If the radiator is original- it will not cool as efficiently as a new one. Fins get bent and clogged, and build up in the lower internal passages start restrict optimal flow. I would try to clean radiator from back side- spraying water forward towards condenser, make sure theres no build up on the front side of rad, drain coolant: including block drains, flush system with distilled, then refill with new.

Also if you havent flushed your trans, you might do that as well- since it cycles through the lower tank adding a fair amount of heat.

If i temp swing really annoys you, spend $175 on a new radiator, and $60 on fluid and change it out. Its an easy job.

I have not flushed the trans fluid yet. It is a dark slightly dirty red color, not a bright vibrant red. You may be on to something with that. It does seem to only get out of 190’s when it has been driven for 20 or more mins. Which could be because the trans is finally heating up. And the engine is less likely to get out of the 190’s if I am doing a lot of idling, maybe because the trans isn’t heating up? Or am I thinking of this engine/trans relationship incorrectly?

 

[Nightbrew]

I did my timing belt last year at 240K, engine temps were one thing that made me want to go ahead and do it sooner than later. I bought the LX at 215K and couldn't confirm it was done at 180K as the sticker implied. I was having an issue with temps that would hover around 205 going down the road. I had a new radiator to install at the same time I did the timing belt as well.

When I did the job I found that the thermostat was dated 2004, so it would have been the original thermostat from the factory. Thinking little about it I changed it and finished the job. I new radiator, hoses, etc also went in and the problem went away. Suspecting it was the thermostat I tested it in boiling water to find it open only a couple millimeters when hot. I needed to do the job but realized if I had applied KISS methodology I could have swapped the thermostat and solve the issue without having to do the timing belt early, as I could tell the timing belt was good when I pulled it out. YMMV

When you were hitting 205 on the road, were you doing a little better temp wise in slower driving situations or stop and go?

 

[abuck99]

I have not flushed the trans fluid yet. It is a dark slightly dirty red color, not a bright vibrant red. You may be on to something with that. It does seem to only get out of 190’s when it has been driven for 20 or more mins. Which could be because the trans is finally heating up. And the engine is less likely to get out of the 190’s if I am doing a lot of idling, maybe because the trans isn’t heating up? Or am I thinking of this engine/trans relationship incorrectly?

IDK- coolant is typically hotter than trans fluid on our platforms- but trans fluid will hold heat longer than coolant. So if trans is running hot, its going to have some small effect on coolant temp. More likely than not, radiator has lost some efficiency. Also poor quality coolant won't maintain its lubricating properties as long as higher quality coolant- so that affects water pump performance- how soon or how much IDK. Unless its SLL, 36months 40-50k is about all you can expect from average coolant before you should flush and replace. Your temps aren't out of the ball park, but if your radiator is showing any visible signs of aging (stress cracking and color change on the upper tank) you might consider a preventive replacement.

Does your model year have the supplemental electric radiator fan?

 

[Nightbrew]

IDK- coolant is typically hotter than trans fluid on our platforms- but trans fluid will hold heat longer than coolant. So if trans is running hot, its going to have some small effect on coolant temp. More likely than not, radiator has lost some efficiency. Also poor quality coolant won't maintain its lubricating properties as long as higher quality coolant- so that affects water pump performance- how soon or how much IDK. Unless its SLL, 36months 40-50k is about all you can expect from average coolant before you should flush and replace. Your temps aren't out of the ball park, but if your radiator is showing any visible signs of aging (stress cracking and color change on the upper tank) you might consider a preventive replacement.

Does your model year have the supplemental electric radiator fan?

I have the electric fan on the front passenger side. I believe that is for the ac correct? Radiator looks good, no browning or cracks. However I have no idea how old it is. If it test the fluid, it won’t tell me anything about it’s lubricating properties, correct?

 

[abuck99]

You can test pH but yeah it wont indicate additive composition. BG makes a wetter that supposedly helps, but honestly its prob better to flush with some good/new coolant. Your model year can use the Toyota SL which you can buy in concentrate and mix with distilled/de mineralized water-

Is the fan turning on & off? It does help the cooling efficiency.

 

[ramangain]

Some definitive tests to try if you want to keep chasing things down, and learning in the process.

Install a flow meter on your cooling system. Post up the results.

Then install a pressure meter before and after the radiator. Post up the results.

Flow should tell you if you have blockage or the pump isn't up to snuff (when compared to known working systems).
Pressure will tell you if the most likely spot for blockage (the radiator) is in fact plugging up.

If I were chasing down similar issues, this is where I'd start rather than going after potential secondary sources of issues (tranny stuff for instance).

 

[Nightbrew]

You can test pH but yeah it wont indicate additive composition. BG makes a wetter that supposedly helps, but honestly its prob better to flush with some good/new coolant. Your model year can use the Toyota SL which you can buy in concentrate and mix with distilled/de mineralized water-

Is the fan turning on & off? It does help the cooling efficiency.

I haven’t checked that electric fan. I will try that soon

 

[Nightbrew]

Some definitive tests to try if you want to keep chasing things down, and learning in the process.

Install a flow meter on your cooling system. Post up the results.

Then install a pressure meter before and after the radiator. Post up the results.

Flow should tell you if you have blockage or the pump isn't up to snuff (when compared to known working systems).
Pressure will tell you if the most likely spot for blockage (the radiator) is in fact plugging up.

If I were chasing down similar issues, this is where I'd start rather than going after potential secondary sources of issues (tranny stuff for instance).

Are these devices for testing something I can rent?

 

[MJK]

The fact that you have higher temps on the freeway than around town suggests that the issue is with the volume/efficiency of the coolant being circulated in the system. Electric fans have little to do with cooling at freeway speeds. IMO your choices are:

A) Ignore it
B) Replace the thermostat/gasket and radiator cap with OEM and see what happens.
C) Flush the whole system with distilled water a few times to get all the crap out, then replace t-stat, the radiator, tees and any hoses that look suspect or feel hard. Refill SL red or Zerex Asian and burp carefully.

 

[SHIfTHEAD]

When you were hitting 205 on the road, were you doing a little better temp wise in slower driving situations or stop and go?

Normally it would cool down. The issue you are experiencing, heating up as you go faster means the coolant is not moving around the system as the engine speeds up. I wonder a failing water pump could be the cause of your problem?

 

[ramangain]

All, I have been having some engine temp concerns. Oddly enough to me my highest temps have been while on the highway, not in stop and go traffic. All temps mentioned in this post are from my ultragauge. So with ambient temps in the 80’s and low 90’s, in town with ac on, I’m seeing 190-196. Same ambient temps on the highway avg 55-60 mph, and I see similar but slightly higher temps, up to 197 or so. However if I go up slight inclines for a while, they creep up even higher. In this scenario 199-203 isn’t rare and I have seen 206-208 a few times. So, I feel like my normal temps are higher than I would like. I’m not sure what to think about temps being higher on the highway. Usually with overheating issues I think slow or stop and go traffic. The only things I have done yet are to check coolant level, which is full, and blow out debris from radiator fins with the compressor. Any thoughts or items to check?

Does your ultra gauge allow for data logging? Graphsxwould bgg e helpful too.