Running Hot (1 Viewer)

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I’ve recently started to think that with the modified clutches and in high heat environments that there might be some belt slip involved. I’ve stared to run wrapped belts which will transfer more torque and and last longer than the factory ones.
 
I’ve recently started to think that with the modified clutches and in high heat environments that there might be some belt slip involved. I’ve stared to run wrapped belts which will transfer more torque and and last longer than the factory ones.
I did have some belt slip months ago, but I tightened it. It would only happen after a certain RPM (3500ish).

You'd think that idling would be the least likely time for belt slip to occur, right? Least amount of force the belt has to transmit.

Belts are under 2 years old, OE toyota.
 
I’ve recently started to think that with the modified clutches and in high heat environments that there might be some belt slip involved. I’ve stared to run wrapped belts which will transfer more torque and and last longer than the factory ones.
Can you point us to some wrapped belts? I've recently started having AC belt slippage. I thought it was tight enough but sometimes I get a bark when the AC kicks on.
 
I had the same issue for years, Low speed crawling hi heat with the AC on the temps would climb. Did all the things listed here, Issue persistent.
On my last go round with the issue I installed a 10% overdrive pulley to the fan/water pump and put the foam around the radiator.
On my last hard core wheeling trip (Fordyce Creek) AC blasting slow speed Crawling temps never went over 197.
Same conditions before It would go 215-220 and I would put it neutral turn the AC off bump the RPM to 1200 and the temp would come right down. Never had to do that the whole trip.
Just wish I had done them one at a time to see if one of them was doing more then the other 🤷‍♂️
I do think the foam around the radiator make a difference!!
The auxiliary Fan won't help with cooling, it just helps keep the AC temps lower.
 
this thread has largely been me questioning whether I'm chasing a non-issue.

Which btw, I looked again today and there are significant gaps on the side supports of the radiator. Will have to pull fan shroud to get to them. This could be why I didn't see any difference between the TYC unit and brass radiator. I didn't put foam on the TYC unit, because the 80 didn't have foam from the factory, you know?

Based on the raventai gauge guide though, I routinely hit about 210* just going through a long drivethru with AC on. Others don't hit this unless they're towing up grade it seems.
I’m not sure that’s accurate regarding 80’s not coming with foam from the factory. A new radiator from Toyota comes with the foam already attached. As far as I can recall the originals I’ve removed had foam as well.
 
I’m not sure that’s accurate regarding 80’s not coming with foam from the factory. A new radiator from Toyota comes with the foam already attached. As far as I can recall the originals I’ve removed had foam as well.
^^^^^This
 
Can you point us to some wrapped belts? I've recently started having AC belt slippage. I thought it was tight enough but sometimes I get a bark when the AC kicks on.
I only know the belts for the alt/water pump.

As always you want to make sure the pulley’s surface is clean and not glazed.
 
I had the same issue for years, Low speed crawling hi heat with the AC on the temps would climb. Did all the things listed here, Issue persistent.
On my last go round with the issue I installed a 10% overdrive pulley to the fan/water pump and put the foam around the radiator.
On my last hard core wheeling trip (Fordyce Creek) AC blasting slow speed Crawling temps never went over 197.
Same conditions before It would go 215-220 and I would put it neutral turn the AC off bump the RPM to 1200 and the temp would come right down. Never had to do that the whole trip.
Just wish I had done them one at a time to see if one of them was doing more then the other 🤷‍♂️
I do think the foam around the radiator make a difference!!
The auxiliary Fan won't help with cooling, it just helps keep the AC temps lower.
Running an undersized pulley and getting better cooling is the same as putting in a fan clutch with a stronger setup. Both increase the fans rotational speed.
 
Running an undersized pulley and getting better cooling is the same as putting in a fan clutch with a stronger setup. Both increase the fans rotational speed.
I’m running one of your modified blue fan clutches that I got years ago from Joey.
It did not fix the issue
The pulley also makes the water pump run faster.
Every mod in this thread has been done as well as all new OEM parts in the cooling system. Including fan & shroud
And all the wheel well engine skirting is present
I also run a after market temperature gauge for real time temperature readings.
Normally driving has never been a issue. Just low speed crawling with hi ambient temperature with the AC on.
The overdrive pulley and foam made the biggest difference.
 
I’m running one of your modified blue fan clutches that I got years ago from Joey.
It did not fix the issue
The pulley also makes the water pump run faster.
Every mod in this thread has been done as well as all new OEM parts in the cooling system. Including fan & shroud
And all the wheel well engine skirting is present
I also run a after market temperature gauge for real time temperature readings.
Normally driving has never been a issue. Just low speed crawling with hi ambient temperature with the AC on.
The overdrive pulley and foam made the biggest difference.
Where do you get this overdrive pulley?
 
I’m not sure that’s accurate regarding 80’s not coming with foam from the factory. A new radiator from Toyota comes with the foam already attached. As far as I can recall the originals I’ve removed had foam as well.
Did not realize this. Bought some foam this morning... will tear it down today and install.
 
I’m running one of your modified blue fan clutches that I got years ago from Joey.
It did not fix the issue
The pulley also makes the water pump run faster.
Every mod in this thread has been done as well as all new OEM parts in the cooling system. Including fan & shroud
And all the wheel well engine skirting is present
I also run a after market temperature gauge for real time temperature readings.
Normally driving has never been a issue. Just low speed crawling with hi ambient temperature with the AC on.
The overdrive pulley and foam made the biggest difference.
By chance did you have an aluminum water pump pulley? Before swapping it out for an undersized one?
 
@iansplatinum
I just completed the replacement of every cooling component and now I've got two 80s running 190.4°F consistently. I didn't have the time (or the coolant) to replace the parts one at a time to see if there was one culprit, or the problem was a combination of problem children.

My new fan clutch is an Aisin blue hub, not modified, and it doesn't seem to be operating any differently than the old one, which I think was the original.

I replaced the OEM plastic tank radiator with a donor (thanks @roadstr6 !) CSF brass and copper model, same size. I had the tanks removed, and the entire assembly cleaned and reassembled, before I installed it. Since it didn't have any foam on it, I attached a strip of self adhesive bar-b-que gasket (foam tape) all around, before I bolted it in. I also flushed the cooling system again, after initial assembly, for good measure. It didn't affect the operating temperature at all.

FWIW, both radiators flow tested the same, before I had the CSF cleaned. I decide to replace the OEM radiator because it was on the truck when the headgasket failed, and the inlet tube seemed to have some heat damage.
 
@iansplatinum,

Another thought just occurred to me, that hasn't been explored here. What are your transmission temperatures? I'm just wondering if a hotter than "normal" transmission would raise the radiator temperature enough to be visible by the ECU, since the tranmission cooler lines run directly into the lower tank. The reason I mention this is that, during one test drive, my son mentioned that he wasn't seeing the same acceleration he was used to given a particular RPM, and, without thinking, I replied that his observation might have more to do with the transmission shift points/operation than the engine response.
 
@iansplatinum,

Another thought just occurred to me, that hasn't been explored here. What are your transmission temperatures? I'm just wondering if a hotter than "normal" transmission would raise the radiator temperature enough to be visible by the ECU, since the tranmission cooler lines run directly into the lower tank. The reason I mention this is that, during one test drive, my son mentioned that he wasn't seeing the same acceleration he was used to given a particular RPM, and, without thinking, I replied that his observation might have more to do with the transmission shift points/operation than the engine response.
I blew my A440F a few months ago on 95 degree ambient temp on a 6 hrs drive up to the Sequoias. It was fully loaded with 4 ppl w/ AC on full blast most of the time and 4k rpm 2nd gear up the mountain @ 7k+ elevation for long duration of time. At one point, my coolant temp was up 217F or so vs 190-195F normally. Long story short, the transmission oil was burnt with shavings. I had replaced with a super low mileage unit and the shifting was smooth like i had never experienced before. Moral of the story, install a transmission oil temp gauge along with an aftermarket coolant temp sensor. Coolant runs between 185-200F and the transmission seems to hover between 160-200F
 
Good point, I need to check this. I could try to bypass the transmission line into the radiator to eliminate that possibility
 
Good point, I need to check this. I could try to bypass the transmission line into the radiator to eliminate that possibility
This is not a good idea unless you double up on the air to oil cooler in front of the radiator and I’m not sure this would be as good at cooling hot trans fluid quickly as the coolant to oil cooler in the radiator.

As stated before, a real time temp gauge in the coolant outlet pipe and one in the transmission oil pan is necessary to see what’s really happening.

Hot trans oil will certainly add to the heat load of the radiator increasing coolant temp. This should be a concern only when the torque converter is unlocked and shearing fluid in warmer weather under the increased demand of towing and/or long ascents where converter lock up can not be maintained.
 
Good point, I need to check this. I could try to bypass the transmission line into the radiator to eliminate that possibility
As @baldilocks said above, that'll work, as long as the transmission is in park.

FWIW, the ECU/TCU has a temp sensor in the circuit somewhere:
1660351921819.png

It should be possible to monitor it via OBDII/Techstream, at least for the '95-'97 models.
 

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