refuge9

So here's my issue. '87 Toyota pickup, 22R (Carbed). My problem is, it overheats. Things I have done in troubleshooting:

replaced the first radiator with one from a donor truck I bought. (Turned out it leaked).
replaced 2nd radiator with one from a junkyard truck. Doesn't leak, may have an occlusion.
replaced 3rd radiator with one from a 94 V6 4Runner. Leaks slightly, but was known to keep the 4runner cool, and did so on a drive from New York to St Louis.

Replaced 1st thermostat with Duralast.
replaced 2nd thermostat with Heavy Duty NAPA
Replace 3rd Thermostat with Toyota OEM.

Replaced all hoses.

Replaced Radiator cap with brand new Toyota OEM cap.

replaced sensors with brand new sensors. (Both sensors on the manifold.)

swapped fan clutch with another from donor truck.

Changed water pump with new water pump.

swapped motor to a newer, lower mileage motor. (Motor was known good, and was pulled from a totaled vehicle that was hit in the back. Engine ran great before being pulled, and did not over heat.)

had carb tuned.

Swapped carb with rebuilt carbed, and had tuned.

I'm at a loss. I've flushed and replaced the coolant so many times... Coolant is a 50/50 mix, and it's now Toyota coolant. I'm about to try pulling the thermostat, and seeing if it will still over heat then, but if anyone has any ideas, PLEASE help! I've tried everything I can think of short of buying a new $300 radiator. This thing should not be overheating, but it still over heats. I've noticed as long as I'm moving, it stays below the overheating range, but if I stop at a stop sign, or a stop light, it starts to creep up really quickly, and will hit the red line. If I start moving again, it will start to slowly cool down.

Both engines used to be EFI, (The truck was originally carbed, but the whole truck was in such poor shape when I got it, the headgasket blew out the first week because of bad belts. bought a donor truck with a bad frame. It was EFI, but the fuel lines were rusted out, and the wiring harness chewed through, so I converted the motor to carbed. Current motor was also pulled from a much newer, well kept truck, but only got a long block, so I had to swap it to carbed as well. Would love to do a EFI swap, but don't have all the components yet.) I don't know if this makes a difference or not.

1986YotaBeast

Maybe check to see if the waterpump may be failing, I would hope that you could go threw 3 radiators/thermostats and it not be one of the causes(So I think those are eliminated), May want to do what you where saying and just take out the thermostat and see if that helps, but that still doesn't make since to me. I'd say check the waterpump, see if the fan shaft has play in it. that may be an indication.

jjyoda_86

if you still overheat after you've removed thermostat try pulling the hoses off the heater core and run a garden hose or the flush tool your using through and flush the heater core out might have a partially blocked heater core. how are you bleeding the system. I would rec running it with the rad cap off for 15 min or more until both heater hoses are warm. at that point when you rev your engine up you should see coolant level drop a little letting you know that your system is flowing freely.

refuge9

I generally leave the cap off when burping the system, and fill it while its running, as it lowers. I'm honestly not sure I've burped the system 100%, but I've used an airlift coolant system to fill it before too, and it seems to be full, and it still over heats then. I've not flushed the heater core, though it overheats pretty much regardless of whether the heater core is open or not. Also, the heat works on that truck really well. (toyota heat), so I don't think it's clogged either.

jjyoda_86

make sure your putting the tstat in correctly. have to say this b/c Ive seen people do this before, by putting it in backwards several times. and if your only overheating at idle Its either your flow of coolant partial block somewhere, bad h20 pump or something in front of your rad is not allowing air flow through it.

refuge9

It should be installed like this, if I remember correctly. It's been a couple months since I installed it, but I believe it won't even let you put it in upside down.

wyoming9

iTrader: (1)

Did i read this correct you have changed every thing but the radiator with new parts.

borrow or buy one of those infrared temp guns I would bet the radiator is blocked it gets enough air while moving but stopped over heats

i would never put a old radiator back in just pulling it out transporting and reinstalling could be enough to knock the build up from all those years loose so one that did work now doesn`t cool any more.

New water pump bad all ready most often if the bearing fails it starts to leak


** I think all my vehicles have new all metal radiators they do break down.

DRTDEVL

Get a new fan clutch. Its the only thing keeping your truck cool at a stop, but it isn't doing it.

Yes, its possible the donor's clutch was bad, too.

I went through this around 2002-ish with my 87. My fan clutch was bad and it heated at a stop. I put a remanned Duralast clutch in and it fixed the problem. My buddy's 85 had the same issue... He put a J/Y clutch in to no avail. Got a remanned one as well, and his cooling system worked again.

Usually the fluid leaks out over time and the clutch begins to freewheel.

refuge9

The first clutch would loosen up the more I spun it with my hand, like the fluid was losing it's resistence. The one from the donor seemed okay, but maybe not.

Either way, I'll probably try buying one. The places near me only have the 'Torqflo' brand, which I am hoping is good enough. There's an Advance somewhere nearby that has a Beck/Arnley, but it's literally 3x the price ($130). neither appears to be remanned. I've already spent thousands of dollars on this truck. It's been a nightmare. (Wiring harness cut by previous owner, cab and bed had a huge hole cut out for speaker box. overheating, electrical problems with the dash that still exist. Exhaust issues, cracked frame which we had to repair. etc.)

It's almost a point of pride at making it work right now. I have an entire rebuild kit sitting around ready to rebuild an engine, but I need this running by next weekend for a trip. If I can make the overheating problem go away, I should be good.

refuge9

So I went and bought a new fan clutch, installed it, and.... still overheating. it went a little above half way sitting at idle, as soon as I took it on the highway, it start heating up, and when I brought it to a stop at a stop sign, it spiked to the 'warning' bar on the gauge. Never actually hit the red line at the top, but it did come close.

Next attempt is to remove the thermostat, and check it, and also run without the thermostat.

Also, I bled the truck more. Made the radiator fill spot the high point as best I could, and burped the hoses, while the truck was running. Still no love. Anyone else got any ideas?

Saturday I will also likely be getting a new radiator ($40 with exchange. It's a 'used' radiator, but it's been checked, and tanked by a shop, and has been effectively remanned.

I will also have a laser thermometer tomorrow to check the actual temp when it's 'overheating'.

refuge9

So, in case anyone wants to know, it looks like this problem is instrumentation. As I mentioned before, this truck's wiring setup was beyond messed up. Looks like there is some weird bleed through of the blinkers to the rest of the cluster. After driving the truck around, and getting it to 'overheat', and then checking the temperature, the temps all looked fine (Never found a spot over 200 degrees F.) I noticed that originally, it seemed like it would randomly spike when I stopped, but it turned out, it spiked when I had the blinkers on. I drove for 40 minutes without using the blinkers, and the truck never once overheated. I also checked the thermostat through hot water, and it was fine. Looks like I've now wasted a bunch of money. Hooray. Getting an SR5 dash later this week to see if it's a wiring problem, or a cluster problem... besides, I want the tach on it.

Marcos1618

sounds like the same problem I had.