123*F, parked on the freeway in traffic (1 Viewer)

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Mar 24, 2013
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Santa Monica, CA
Yesterday was an interesting day. Left Palm Springs around 1pm to drive the family back to Los Angeles. It was HOT! My 1997 has a very well sorted cooling system, I think. Just overhauled the system a month or so back with a new OEM radiator, new radiator cowl, new fan, new coolant, etc. And I run a Wit’s End blue fan clutch. All of this is running on a factory new long block engine overhaul less than 15k miles ago.

Normally, my truck runs a very reliable 181-185. With triple digits on the ambient temp gauge, a full load of vacation gear in back, AC blasting, I was just touching 190* on the Ultragauge.

But leaving Palm Springs yesterday, we hit a complete bottleneck of traffic in a construction zone. To make matters worse, it was a long shallow incline, so there was added load. In very slow stop and go traffic, temps seemed stable at 210 with the AC on max. Not terribly worried, but I was paying close attention. Then traffic parked and we had absolutely nowhere to go and zero air through the rad. It spiked quickly to 217, then 220, then 227. That’s when the AC shut off.

To my wife’s horror, I rolled down all the windows and blasted the heat on high. Turned the rear aux heater on max as well. Watching the ultragauge, temps absolutely PLUMMETED. No exaggeration, within one minute, temps dropped to 199* and help solid. The kids were cheering like USA just beat Russia in hockey. It was pretty spectacular actually. Took about five mins before traffic started moving again, and as soon as it did, the windows went back up and the AC was back on max.

All a long way of saying, would this be considered a reasonable response, or should a well functioning 1FZ system have more headroom? I kinda feel like asking just about any engine to maintain its composure in 120+ heat on a parked freeway is a tall ask.
309E4FF8-F8B6-41E7-873C-B0F407D52270.jpeg
 
Yep, the engine heat soaks, plus added heat exchange from the AC, and ambient temp of 120 plus, not surprised in stop and go traffic. My coolant temp hits 210 a few times on my drive back from Moab, Utah fully loaded with 4 ppl and 2 weeks of gear and full AC with a very sorted coolant system. The dual Spal pusher fans does wonder for keeping air flow to the AC condenser on traffic and slow 4Lo types wheeling...227F for the 4.5L, i will be worried a bit....
 
Next time throw it in neutral and bring the revs up, that should drop temps pretty quickly and keep the A/C alive while sitting. It doesn't take very much RPM to get the fan to pull giant piles of air through the condenser and radiator. Heck if traffic is moving slow throw it in low range while creeping.
 
Yesterday was an interesting day. Left Palm Springs around 1pm to drive the family back to Los Angeles. It was HOT! My 1997 has a very well sorted cooling system, I think. Just overhauled the system a month or so back with a new OEM radiator, new radiator cowl, new fan, new coolant, etc. And I run a Wit’s End blue fan clutch. All of this is running on a factory new long block engine overhaul less than 15k miles ago.

Normally, my truck runs a very reliable 181-185. With triple digits on the ambient temp gauge, a full load of vacation gear in back, AC blasting, I was just touching 190* on the Ultragauge.

But leaving Palm Springs yesterday, we hit a complete bottleneck of traffic in a construction zone. To make matters worse, it was a long shallow incline, so there was added load. In very slow stop and go traffic, temps seemed stable at 210 with the AC on max. Not terribly worried, but I was paying close attention. Then traffic parked and we had absolutely nowhere to go and zero air through the rad. It spiked quickly to 217, then 220, then 227. That’s when the AC shut off.

To my wife’s horror, I rolled down all the windows and blasted the heat on high. Turned the rear aux heater on max as well. Watching the ultragauge, temps absolutely PLUMMETED. No exaggeration, within one minute, temps dropped to 199* and help solid. The kids were cheering like USA just beat Russia in hockey. It was pretty spectacular actually. Took about five mins before traffic started moving again, and as soon as it did, the windows went back up and the AC was back on max.

All a long way of saying, would this be considered a reasonable response, or should a well functioning 1FZ system have more headroom? I kinda feel like asking just about any engine to maintain its composure in 120+ heat on a parked freeway is a tall ask.
View attachment 2716216
I used to live in Indio Hills. I installed twin electric fans that I manually turn on whenever I was moving slow or in traffic for that very reason. It also works great when in slow moving off road conditions on hot days. I usually let the fans run for a bit after I turn off the engine as well.
 
Next time throw it in neutral and bring the revs up, that should drop temps pretty quickly and keep the A/C alive while sitting. It doesn't take very much RPM to get the fan to pull giant piles of air through the condenser and radiator. Heck if traffic is moving slow throw it in low range while creeping.
hand throttle comes in handy for that...
 
This sounds typical but I wish there was more headroom. Similar happened to me over the grapevine in gridlock at similar temps.
neutral revving does nothing. probably creates more heat
aux fan would probably not do much but i'm going to try setting one up that isn't janky, for low speed a/c
 
This sounds typical but I wish there was more headroom. Similar happened to me over the grapevine in gridlock at similar temps.
neutral revving does nothing. probably creates more heat
aux fan would probably not do much but i'm going to try setting one up that isn't janky, for low speed a/c
If neutral revving does nothing you need to figure out whats wrong. You should have a roaring fan at 1100rpm if its that hot.
 
Data point checking in here. * I think my system should be running cooler too..

Ambient temp 107° 22k CST in the blue fan clutch, single auxiliary fan running, fully loaded, here's the UG and the thermometer info... ive never seen my AC get colder than 40* , i wish i could get it colder & engine temp down a bit more... when crawling over the weekend i was hitting 210-212 until i brought the RPM's around 2k then it started to cool...

PXL_20210627_222707589.jpg


PXL_20210627_222705080.jpg
 
There’s room to grow there. Try stepping up to 30k oil in the fan clutch. It’s cheap and easy for a first move. Has your cooling system been overhauled yet?
Data point checking in here. * I think my system should be running cooler too..

Ambient temp 107° 22k CST in the blue fan clutch, single auxiliary fan running, fully loaded, here's the UG and the thermometer info... ive never seen my AC get colder than 40* , i wish i could get it colder & engine temp down a bit more... when crawling over the weekend i was hitting 210-212 until i brought the RPM's around 2k then it started to cool...

View attachment 2716686

View attachment 2716692
 
There’s room to grow there. Try stepping up to 30k oil in the fan clutch. It’s cheap and easy for a first move. Has your cooling system been overhauled yet?
Okay, I can step it up.

I have new denso radiator, hoses, thermostat, engine rebuilt, like 15k mi ago.

Last summer, replaced the compressor, expansion valve, pressure switch.

Maybe i need to replace the dryer ?
 
I'd vote for thicker silicone in the fan clutch as well. I did this a few years ago and it made a noticeable difference in engine temps.

@midfat do you go down to Palm Springs often? I think I may have seen you a few weeks (maybe its been 1-2 months) ago driving on the 74. (Was driving my Ford though). I've lived here my entire life and it was my first time going over there!
 
Agreed with my modded clutch I can hold a cat against the grill at 1500 rpm in hot weather.
funny! but agree as well. left foot braking, switching to neutral, keeping up revs to keep the temp from creeping up on a slow crawl (with AC on). I didn't realize i need to master that technique just to keep the engine cool :D

It kinda sucks to turn off the AC when you need it the most (and turn on the heater), but that's what we did to make sure I keep the temps in check, especially when you're in a middle of a 4000mile trip in nowhere land. Sometimes i feel like i would not have cared if i didn't have UltraGauge but there's no turning back now.

i would let the engine run for awhile before shutting off the engine. Even at idle, temps will dive down to 190F even after starting at >200F on a 110F day after awhile which proves that even my 10K CST modded blue fan works enough to cool the engine down at idle.

Another somewhat related datapoint re overall cooling performance. i have an ARB front bumper. I started my trip with a license plate and 7" round offroad lights. Less than 100 miles from the trip, stable ambient, early AM (no heatsoak), i discovered that removing the plate then the lights resulted in incremental reduction of temp! Coolant temp and IAT were significantly down meaning the plate and the lights do indeed reduce the airflow. Anyways, just thought some folks may find this info useful when dealing with temps rising on the highway.
 
A hand throttle works wonders in these situations where your road trip comes to a halt due to whatever reason and the road becomes a parking lot or even in slow moving or stop and go traffic. Just stepping the rpm up to double that of idle makes a huge difference.
 
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These posts make me wish the intake did not sit over the exhaust, and that the engine compartment vented heat better when still or moving slowly. It's a weakness of these rigs, IMO.
 
These posts make me wish the intake did not sit over the exhaust, and that the engine compartment vented heat better when still or moving slowly. It's a weakness of these rigs, IMO.

I actually thought of adding heat wrap to the intake section but run out of time prior to my trip. Hopefully i'll find some time to run some tests on IAT with heat wrap and none to see if it drops the IAT. I do feel the same way about the lack of insulation between intake/exhaust
 
These posts make me wish the intake did not sit over the exhaust, and that the engine compartment vented heat better when still or moving slowly. It's a weakness of these rigs, IMO.
My dodge with Cummins diesel is set up with intake and exhaust on the passenger side same as the 80 with the same location for oil cooler as well. I don’t think we can blame this design on the subject here.

This thread was born of a very extreme condition rare to most of us if ever we experience such condition’s. I wouldn’t expect anything but what the OP experienced at idle in 123f outdoor temps.

The inner aprons are short and then use the plastic/rubber apron seals to deflect mud and other debri from entering the engine bay but also allow air flow which we won’t have much of at idle. This is why suggested a hand throttle earlier, mine has saved me many times in different ways.
 
Yesterday was an interesting day. Left Palm Springs around 1pm to drive the family back to Los Angeles. It was HOT! My 1997 has a very well sorted cooling system, I think. Just overhauled the system a month or so back with a new OEM radiator, new radiator cowl, new fan, new coolant, etc. And I run a Wit’s End blue fan clutch. All of this is running on a factory new long block engine overhaul less than 15k miles ago.

Normally, my truck runs a very reliable 181-185. With triple digits on the ambient temp gauge, a full load of vacation gear in back, AC blasting, I was just touching 190* on the Ultragauge.

But leaving Palm Springs yesterday, we hit a complete bottleneck of traffic in a construction zone. To make matters worse, it was a long shallow incline, so there was added load. In very slow stop and go traffic, temps seemed stable at 210 with the AC on max. Not terribly worried, but I was paying close attention. Then traffic parked and we had absolutely nowhere to go and zero air through the rad. It spiked quickly to 217, then 220, then 227. That’s when the AC shut off.

To my wife’s horror, I rolled down all the windows and blasted the heat on high. Turned the rear aux heater on max as well. Watching the ultragauge, temps absolutely PLUMMETED. No exaggeration, within one minute, temps dropped to 199* and help solid. The kids were cheering like USA just beat Russia in hockey. It was pretty spectacular actually. Took about five mins before traffic started moving again, and as soon as it did, the windows went back up and the AC was back on max.

All a long way of saying, would this be considered a reasonable response, or should a well functioning 1FZ system have more headroom? I kinda feel like asking just about any engine to maintain its composure in 120+ heat on a parked freeway is a tall ask.
MidFat;
Being a fourth generation Texan, I can tell you... NO ONE gets use to this level of heat.. I even remember "a few years back" (like the late '60's/early '70's) when MOST automobiles did NOT even have Air Conditioning.. Hell, neither did most houses!! (one was damned fortunate if one had a "window unit" in the bedroom.. "Central Heat/Air" was for the "rich folks"!!)
Needless to say, I still live in Texas and we are NOT experiencing the temperatures the west coast and Pacific Northwest are.. BUT y'all ARE experiencing temps like WE do during the normal "hot period" of our summers (between May and October!!)
It is NOT uncommon for us to experience engine temps climbing to "O, Ma Gawd" territory in July & August!! OR during the DFW Metroplex rush-hour traffic (when the office commuters sit and stare at their cellphones while the signal light changes several times!!!)
Generally speaking, our initial "common cure" to climbing engine temps is to simply put the vehicle into neutral then raise the engine RPMs to a "fast idle".. sometimes up to 2500 rpm. If your vehicle is either fairly new and/or your cooling system is in very good condition, this action will bring your engine temps down pretty quick... and the family doesn't have to suffer the "blast furnace" temps "Ol Sol" is inflicting! Bottom Line, Ya Done Okay! Do note, however, the "engine temp" WILL continue to rise even tho you turned-off the engine!! It's called "Heat Soak"!
I might note, I was a mechanic in a Datsun dealership in the late '60's early '70's. The commonly fitted "add-on" air conditioning units (under dash units) came with a "heavy duty" radiator.. I recall it was simply a thicker radiator (an extra row of cooling tubes).. This "allowed" the owner to drive in-traffic with their A/C on and NOT over-heat the engine.. This ALSO necessitated changing the thermostat twice a year.. a 160* for summer and a 180* or 190* for winter.. Given a LOT of "modern" cars, now-a-days, run "normal temps" of 190*+ year round, I imagine there are not many semi-annual t-stat changes anymore!!
A number of years ago, I replaced my '70 Datsun's original radiator with an all aluminum job.. believing it would "help" keep the engine temps down.. Total Waste of (then) $300!! I reinstalled the original radiator, changed T-Stats as I had always done, everything was "back to normal"!!
I'll note that when my FJ40 was my "daily driver" (and used as a "farm truck" from 1986-1990), the 1967 429cid Cadillac Engine fitted with the original 1967 Cadillac Radiator (and the A/C Condenser in front of it!).. I could let the LandCruiser "sit and idle" for "a while" (like when loading a 20" flatbed with 60lb bales of hay) on an average 100+ degree day (in Texas) and the engine temp would never exceed 210*. I put it in "Drive", take-off "normally" and before it's shifted into "top" gear, the engine temp would drop back down below 180*!
Also, in 1980 when the USA Hockey Team beat the Russians in the "The Miracle On Ice", The USA Team Captain, Mike Eruzione [Boston, Mass] is my first cousin... That was the ONLY hockey game I ever watched and Mike never played another game of hockey.
 
I actually thought of adding heat wrap to the intake section but run out of time prior to my trip. Hopefully i'll find some time to run some tests on IAT with heat wrap and none to see if it drops the IAT. I do feel the same way about the lack of insulation between intake/exhaust
There's a thread somewhere here where @NLXTACY did that, looked like something straight from NASA. I believe he came to the consensus that a snorkel was the best way to lower IAT .
 

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