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Hey everyone ran into an issue yesterday offroading snd wanted to get some thoughts.
truck
86 pickup, 4x4 auto. 5:29 gears dual spools, 35s, 68k miles original motor
I've driven the truck around town and even rock crawling for extended times and temp guage barely moves.
Yesterday I went out trail riding with some friends and the temp guage shot up to about 3/4 up just before the red. This has never happened. The trails we were on are mostly sand and thick mud so I'm thinking that it was just the motor really working to spin the tires in the sand. Once i let it cool, I was able to drive home without a single issue and the temp guage went down and stayed at 1/4 above the bottom line.
I did have the ac in the whole time and it never got hot.
So before I go throwing money at it I'm wondering you guys opinions on what I should look at.
I was thinking cooling system flush, new radiator cap, checking the t stat, then doing a leak down test and compression test just to see if its hesdgasket issue.
what's you guys thoughts? Heres my truck. Still a work in progress
You got a proper radiator shroud? Fan clutch in good condition??
Fact is that here in the ovenlike southwest that I love so well, When it's 105+, even a perfect 22re will get hot, pulling big tires long distance, through deep, soft sand.
You got a proper radiator shroud? Fan clutch in good condition??
Fact is that here in the ovenlike southwest that I love so well, When it's 105+, even a perfect 22re will get hot, pulling big tires long distance, through deep, soft sand.
Yessir. The fan operates as it should and it does have a shroud. I checked my fluid today and the radiator was full but the overflow was a little low. It was hot enough yesterday for the fluid to bubble out of the overflow once. That's when I turned off the rig to let it cool. Granted I had just trudged a long water crossing with a thick mud bottom.
You got a proper radiator shroud? Fan clutch in good condition??
Fact is that here in the ovenlike southwest that I love so well, When it's 105+, even a perfect 22re will get hot, pulling big tires long distance, through deep, soft sand.
Hey, Millball,
I know what you mean exactly. I lived in Yuma for nearly 30 years, so I know how "warm" it can get!
I used to take my 4Runner out "boonie hopping" every chance I got. It would get up above a 1/2, almost to 3/4 on the temp gauge, but it never over heated.
At leat not till a "friend" threw the water pump belt one day I let him borrow it. He didn't even look to see if I had a belt in my parts box. Just drove it till it over heated, let it cool, drove it again, let it cool off, until he got to my house. Boy was he red when I waved the replacement belt I had at him. Had all the tools to fix it aboard as well. So I had to replace the cracked head, twice (got a bad one from the manufacturer the first time). Yes, he did pay for the new head, gasket set, etc.
Other than that little episode, even on the 110-115°F afternoons driving out to work, an hour one way, no shade.
Other than that, I never had a bit of trouble with it.
You current plan sounds good to me, for what that's worth, WarWagon. If you can, flush that system several times, until you get NO more coolant out no matter what, and try and get ahold of some of the Toyota red coolant. It works best in our trucks. Little more expensive, but well worth it! Same for the Toyota 2 stage thermostat, and a Toyota OEM radiator cap.
Worst case scenario, there are 3core radiators that fit our trucks beautifully. I put one in both my trucks, and they worked like a dream. Just a thought...
Pat☺
I'm also working on intermittent "running hot but below upper white mark" myself (here).
Proper flushing / maintenance of the cooling system is important. HOWEVER, gotta verify that it is indeed running hot. It could also be the temp sender, a $21 OEM part, that's bad.
Using an infrared thermometer, I and other members read around 190°F on the thermostat housing at NORMAL operating temp. When the gage shows it running hot, I measure same. I ordered OEM replacement sender.
My radiator also looks like it had seen better years, and I do not trust what previous owner may have done to it so I spent some of the stimulus check on a CSF 2314 Hoping to do switch this week.
Thanks for the suggestions! I'm doing a cab swap here in a couple weeks so while I've got the radiator off I'm going to send it to a shop to get cleaned. Figure the 2 stage thermostat is worth it as well. I'll check the temp sender/sensor and see if it's working or not as well.
I just found it odd since it's only happened the one time. Driving on road is fine and even slow rock crawling situations.
On a lighter note I'm picking up this sweet relatively rust free cab Sunday for 300$. Mine is so rusted it leans to the driver side lol the core support is a little bent but other than that and some small rust spots near the windshield shes miles ahead of my current cab pretty excited to dig in to this
so while I've got the radiator off I'm going to send it to a shop to get cleaned.
Radiator shop will be happy to clean your radiator. Just remember that when they rod the cores, there is a bit of the rod left at the bottom of the core. Enough of that, and the cores actually clog up, and you radiator is no longer efficient. It may even clog up to where it doesn't cool worth a darn. Once or three times getting the cores rodded, no problem. After that, new radiator time.
I just take a look into the cap, yeah a limited view I grant, to see if any cores I can see look clogged, and if they do, new radiator time.
I'll check the temp sender/sensor and see if it's working or not as well.
Something to check on: If the PO didn't use distilled water exclusively, and many don't (ahem, not ME of course<walks away whistling a little tune>), the sender can have build up on the part that extends into the water, causing bad, slow (it takes longer for the real water temp to get "into" the actual sensor portion of the sender through the build up), or no readings on the gauge. Yes, the sender IS bad at that point, but: If you pull it out, and scrub (chip??) the deposits off, it may rectify the situation completely. It may not, too, but it's a way to possibly save yourself a few dollars. Just a thought, while you have it out anyway. Remember there are actually two senders, too. One for the gauge, one for the ECU, I think. One for the cold start injector, too. If there is a build up one on, there will be on all.
Glad for the new, to you, cab! It LOOKS in good shape indeed.
A thought though: Pull the trim off and check the area right around the glass, where the glass is held in with the putty-like stuff, that I can't recall what is called. That is a known rust area. Apparently it holds water in that area, and allows rust to develop. I've even seen one person removed the trim and left it off. I'm not sure how, but he made it look like it came that way from the factory. Looks really good!
Good luck on all this, and anything else you find.
Have fun!
Pat☺
West Palm, ok. Is that above picture from Corbett by any chance? I'm in Broward, been to Corbett a few times 9+ years ago, haven't been in a while, never seemed to be much challenging terrain there to really enjoy.
West Palm, ok. Is that above picture from Corbett by any chance? I'm in Broward, been to Corbett a few times 9+ years ago, haven't been in a while, never seemed to be much challenging terrain there to really enjoy.
Yes it is. I live 10 minutes from there. Its honestly not a fun area. Too much water most of the time. Have you been over to lazy springs? It's a small offroad park but theres some man made rock obstacles and some trails to run. Plus theres a dirtbike course there and lakes for jetskis. Worth the drive.
Warwagon,
I was running my 91 4Runner last summer with a new engine rebuild and a Champion aluminum radiator with a 16" Zirgo shrouded to the back and thought I had the cats meow in cooling capacity. It was a hot day, high 90's in the shade, climbing up several thousand feet in CA and the gage took on a bit of a jump to almost red and was certainly above half which it usually never wanders from. The Derral thermal swith was on and the fan was a spinning and I had to back off on my pace. Well the thermodynamic equation you need to keep in mind with a cooling system is this one (P1*V1)/T1=(P2*V2)/T2. When the pressure falls off the temperature will rise to maintain equilibrium. In my case it was a stinking hose clamp on the radiator which had burped some coolant and thus the pressure dropped and some volume was lost so for that moment the temp went up until the pressure could build back up again. Took another week to find were the tell tail green goo had osed from the upper hose and here I am thinking I had the clamps tight but not too tight on the new radiator and hoses. Stant hose clamps not the OEM spring clip ones which seemingly self tighten for a time as things expand and contract. So I find I am checking and giving the screw clamps a slight twist with oil changes until things get well bedded in.
The other thought, as your in Florida, I was wondering about the muddy water and if you had gotten mud into the radiator and it had not gotten flushed out. The problem in CA is salty air that corrodes the outside of the radiator fins and then the ruddy air won't go through it to carry the heat away. This is the same thing as the mud in retrospect.
Just a thought!
Last edited by Andrew Parker; Jun 5, 2020 at 02:51 PM.
Warwagon,
I was running my 91 4Runner last summer with a new engine rebuild and a Champion aluminum radiator with a 16" Zirgo shrouded to the back and thought I had the cats meow in cooling capacity. It was a hot day, high 90's in the shade, climbing up several thousand feet in CA and the gage took on a bit of a jump to almost red and was certainly above half which it usually never wanders from. The Derral thermal swith was on and the fan was a spinning and I had to back off on my pace. Well the thermodynamic equation you need to keep in mind with a cooling system is this one (P1*V1)/T1=(P2*V2)/T2. When the pressure falls off the temperature will rise to maintain equilibrium. In my case it was a stinking hose clamp on the radiator which had burped some coolant and thus the pressure dropped and some volume was lost so for that moment the temp went up until the pressure could build back up again. Took another week to find were the tell tail green goo had osed from the upper hose and here I am thinking I had the clamps tight but not too tight on the new radiator and hoses. Stant hose clamps not the OEM spring clip ones which seemingly self tighten for a time as things expand and contract. So I find I am checking and giving the screw clamps a slight twist with oil changes until things get well bedded in.
The other thought, as your in Florida, I was wondering about the muddy water and if you had gotten mud into the radiator and it had not gotten flushed out. The problem in CA is salty air that corrodes the outside of the radiator fins and then the ruddy air won't go through it to carry the heat away. This is the same thing as the mud in retrospect.
Just a thought!
That's a valid point. I typically stay away from mud and water as my last rig (jeep) I went through so many radiator fans and brake calipers I couldnt stand it anymore. 3 fans in 6 months due to water crossings and mud nand 6 calipers in a year. After that I stay as far away as I can.
I'm gonna pull the radiator when I do my cab swap and make sure to clean the cooling system really well.
Warwagon - I have not heard of Lazy Springs, but I'm now going to look it up, that sounds interesting...thanks.
If you wanna go sometime I'm down to ride with. I usually have a friends that go and it's a good day trip. The park is small but it's fun. I'll give you a shout when I get my rig swapped and running again.
Running hot at slow speed is usually an airflow issue. Most commonly mud, bugs, sand, leaves, etc. packed in the radiator. Could also be your fan clutch (I don't know how to test one, but if it's not locking up when hot....my mechanical fans all go in the trash, but I live in a climate that's pretty easy on cooling systems).
Jun 2, 2020 | 12:22 PM
Hoping to do switch this week.
