96 3.4 4runner overheating and stumped
12-08-2011, 03:56 PM
#21
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That was why I mentioned a compression check but I don't think we've made it that far yet...he hasn't even burped it. And, if the heads were warped, there would likely be multiple breeches in the sealing surfaces causing a milkshake, oil in water, white smoke, low compression, or any combination of the these.
Let's start with the easy stuff...BURP IT.
Let's start with the easy stuff...BURP IT.
12-08-2011, 04:32 PM
#24
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Now, burp it again after changing the hose with the fan on high and the heater on hot and the nose uphill.
12-08-2011, 04:49 PM
#25
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New aisin clutch fan installed....... Still overheating. Now i turn heater on full blast and the temp goes back to normal, but only if heater is on full blast. Im really getting depressed here. Engine runs great and has tons of power. Could a bad lower raditor hose be the culprit?
12-09-2011, 10:20 AM
#28
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So i burped all the air out. Parked on steep slope with radiator the highest point. Now it will overheat unless i have heater on full blast. Ive searched and not been able to find anything similar. So is a compression test my only other option?
12-09-2011, 11:10 AM
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Just to confirm...you elevated the front end, removed the radiator cap, and ran the engine up to operating temp with the heater on full blast?
Remember the thermostat has to open and it can take a while for all the air behind it to make it's way through the bypass hole you drilled (hot air won't open it). Once it's open you want to continue to run the engine with the heater blasting for a minute or so.
Not second guessing you, just want to be certain you got all the air out. It can be a PITA sometimes and I'd hate to see you tear back into the motor for nothing. You never mentioned what brand thermostat you are using either...did you test it before you installed it?
Remember the thermostat has to open and it can take a while for all the air behind it to make it's way through the bypass hole you drilled (hot air won't open it). Once it's open you want to continue to run the engine with the heater blasting for a minute or so.
Not second guessing you, just want to be certain you got all the air out. It can be a PITA sometimes and I'd hate to see you tear back into the motor for nothing. You never mentioned what brand thermostat you are using either...did you test it before you installed it?
Last edited by BMcEL; 12-09-2011 at 11:19 AM.
12-09-2011, 11:42 AM
#30
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I ran it for a good 20 minutes and temp gauge was at normal temp for quite a while. No air bubbles came out for at least 5 minutes before i put cap back on. The thermostat is not oem and i did not test it. I guess i should replace it for the third time lol. Maybe i will just gut it and see if that works?
12-09-2011, 11:58 AM
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I ran it for a good 20 minutes and temp gauge was at normal temp for quite a while. No air bubbles came out for at least 5 minutes before i put cap back on. The thermostat is not oem and i did not test it. I guess i should replace it for the third time lol. Maybe i will just gut it and see if that works?
Sorry if I missed this, but what did you replace the radiator with? New/used? OEM/not?
12-09-2011, 01:48 PM
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At this point I would even test the OEM unit before installing it. Quick and easy to do.
Edit - don't remember if I mentioned this or not but it's critical that the air bypass (hole or jiggle valve) is on top. Otherwise it will take forever to get all the air out.
Edit - don't remember if I mentioned this or not but it's critical that the air bypass (hole or jiggle valve) is on top. Otherwise it will take forever to get all the air out.
Last edited by BMcEL; 12-09-2011 at 01:54 PM.
12-09-2011, 02:11 PM
#34
enapa- Can you post some pics of the front of your truck(the grill) and then pop the hood and shoot some pics of the new radiator and the shroud...the upper hose area...and sneak under the truck and shoot the lower hose (with flash). Kinda points to the radiator but I can't put my finger on it...
12-12-2011, 09:03 AM
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Dustrider i have checked and the exhaust is looking good. Im sitting at the dealer with my 06 corolla getting the computer recall taken care of. I have to say the oem tstat is waaaaaay different. Different shape and much bulkier. Im hoping this solves my issue. Wont be able to change it until tonight, wish me luck lol
12-14-2011, 06:51 AM
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Well the oem tstat, tested, didnt change anything. Will overheat at idle now. Returns to normal temp with heater on full blast. Guess my only option is to run a gutted tstat.
