Replacing T-Stat on 93 4Runner
#1
Replacing T-Stat on 93 4Runner
I replaced the radiator on my 93 4runner SR5 V-6 last night and it is still overheating. Overheated within 5-10 minutes from totally cool, coolant in reservoir was violently bubbling. No white smoke and oil is clean. Several people have suggested replacing the thermostat so I bought one today. Where is the thermostat on this model? Do I need to remove the radiator again to replace it? This is my first time working on my car and I am having a hard time finding the videos for the right 4runner. in the picture I am attaching you can see that the hose is slipping back, could that be contributing to it? I bought a new clamp since I can't seem to get that one tight enough. I would be super appreciative of any adice on this that anyone could give me! Thanks!
#2
Registered User
You probably have air in the system. Turn your heater to hot, this allows coolant to pass through the heater core. let it idle with the radiator cap off for a while. This can take 30 minutes or so. It will usually burp out the air. Keep an eye on coolant level make. You don't want it full to the top while its burping, it just splashes out.
#3
Trying to let the air out
Alright, thanks! I've had it running for 14 minutes, coolant sprayed out everywhere and it's steaming. Heater is on full blast. Hope this works!
#5
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The thermostat is under the housing at the engine-side of the lower radiator hose. http://web.archive.org/web/201311071...10thermost.pdf
You may have the wrong upper radiator hose (or your new radiator may have a smaller outlet port, which means it's the wrong radiator). The radiator hose should fit pretty snugly onto the radiator port; the clamp doesn't add that much.
If your thermostat isn't opening at all, then no hot coolant is entering the radiator. So I wonder if that's the problem at all. Instead, you could have a bad head gasket, which is allowing exhaust into the coolant, which will allow overheating quickly. For a slow leak, you can use a Combustion Leak Detector. You can borrow one for free from Autozone https://www.autozone.com/loan-a-tool...-leak-detector , but you'll have to pay for the fluid. (The fluid (Bromothymol blue) changes from blue to yellow in the presence of carbon dioxide, which should not be in the coolant.)
But for the kind of leak you may have, there's an even simpler test: attach a nitrile glove to the radiator fill.
Last, get yourself a box of nitrile gloves. You'll have a lot more fun doing this work if you can keep your hands clean.
You may have the wrong upper radiator hose (or your new radiator may have a smaller outlet port, which means it's the wrong radiator). The radiator hose should fit pretty snugly onto the radiator port; the clamp doesn't add that much.
If your thermostat isn't opening at all, then no hot coolant is entering the radiator. So I wonder if that's the problem at all. Instead, you could have a bad head gasket, which is allowing exhaust into the coolant, which will allow overheating quickly. For a slow leak, you can use a Combustion Leak Detector. You can borrow one for free from Autozone https://www.autozone.com/loan-a-tool...-leak-detector , but you'll have to pay for the fluid. (The fluid (Bromothymol blue) changes from blue to yellow in the presence of carbon dioxide, which should not be in the coolant.)
But for the kind of leak you may have, there's an even simpler test: attach a nitrile glove to the radiator fill.
Last, get yourself a box of nitrile gloves. You'll have a lot more fun doing this work if you can keep your hands clean.
Last edited by scope103; 05-21-2020 at 03:58 PM.
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