Overheating-3 Weeks in 2 Shops Still No Cure

That 12 o'clock jiggle valve position is definitely an issue, but like [MENTION=115020]ThorInc[/MENTION] stated, it's probably not 100% of the problem.

Your fan clutch is probably ok since it's only 2 years old, but if you want to test it, I made a video of testing and replacing the fan clutch on my truck. Maybe you'll find it useful.

<iframe width="560" height="315" src="https://www.youtube.com/embed/WzhlACxqeqQ" frameborder="0" allowfullscreen></iframe>
 
mtbtim said:
That 12 o'clock jiggle valve position is definitely an issue, but like [MENTION=115020]ThorInc[/MENTION] stated, it's probably not 100% of the problem.

Your fan clutch is probably ok since it's only 2 years old, but if you want to test it, I made a video of testing and replacing the fan clutch on my truck. Maybe you'll find it useful.

<iframe width="560" height="315" src="https://www.youtube.com/embed/WzhlACxqeqQ" frameborder="0" allowfullscreen></iframe>
Click to expand...

Fan clutch seems to be ok after testing it.
 
CowboyBob said:
Also, the lower hose never collapsed or kinked.
Click to expand...

Came across an issue of overheating. And every part check out fine. Including the outside view of the lower radiator hose. It looked good from the outside when the engine was running.
What was happening was the inside was delaminating from the rest of the hose when there was enough suction flow at higher rpms.
All was fine after replacing the hose.
Don't know if this pertains to you as your hose is around a year old. But, it's worth looking into since you tried almost everything. Good luck.
 
CowboyBob said:
I asked my mechanic about this product and he said that the leak down test pretty much does the same thing. I may try it anyway.
Click to expand...

Your mechanic is right, it won't say anything that a leak-down didn't show.

Most of the comments on here are spot on, it's an internal cooling issue if at highway speeds you are overheating. You've got a blockage somewhere.

I know this is frowned upon by some, but remove the thermostat and take it for a drive. If it doesn't overheat you've found your problem. A faulty thermostat not opening will make it overheat.
 
gamefreakgc said:
Your mechanic is right, it won't say anything that a leak-down didn't show.

Most of the comments on here are spot on, it's an internal cooling issue if at highway speeds you are overheating. You've got a blockage somewhere.

I know this is frowned upon by some, but remove the thermostat and take it for a drive. If it doesn't overheat you've found your problem. A faulty thermostat not opening will make it overheat.
Click to expand...

I like this idea but why not just take it a step further and just put a new thermostat and gasket in with the jiggle valve at the 6 o'clock position and save yourself some time and energy. This way, if it was the thermostat, you don't have to once again drain the coolant, remove the lower radiator hose, remove the elbow that houses the thermostat, put it all back together, and fill it with coolant. A thermostat and gasket is not expensive so just replace it.

And, here's a video that I did covering the replacement of the thermostat. The thermostat replacement coverage starts at 41:24 play time.

<iframe width="560" height="315" src="https://www.youtube.com/embed/2nVbwe2t2T8" frameborder="0" allowfullscreen></iframe>
 
gamefreakgc said:
I know this is frowned upon by some, but remove the thermostat and take it for a drive. If it doesn't overheat you've found your problem. A faulty thermostat not opening will make it overheat.
Click to expand...

I pulled the radiator, thermostat and upper/lower hoses this morning.

The thermostat is new OEM Toyota. It doesn't have 50 miles on it. The mechanioc was correct, he installed it at 12 o'clock. I put it back in with jiggle valve at 6 o'clock. I took a flashlight and small mirror on a stick and check hoses. None show any signs of kinking or delamination.

I took the radiator to the local radiator shop and they are checking it for clogs and defects. When I drained it, there was garbage that came out and the particles are about the size of a grain of sand. So I am hoping that the radiator is clogged and I can be done with this problem. I should know by the end of day.
 
CowboyBob said:
I pulled the radiator, thermostat and upper/lower hoses this morning.

The thermostat is new OEM Toyota. It doesn't have 50 miles on it. The mechanioc was correct, he installed it at 12 o'clock. I put it back in with jiggle valve at 6 o'clock. I took a flashlight and small mirror on a stick and check hoses. None show any signs of kinking or delamination.

I took the radiator to the local radiator shop and they are checking it for clogs and defects. When I drained it, there was garbage that came out and the particles are about the size of a grain of sand. So I am hoping that the radiator is clogged and I can be done with this problem. I should know by the end of day.
Click to expand...

How much are they charging to check your radiator? If it's a decent amount, I think this was a missed opportunity to just put the money towards a new radiator instead. Many of us have just renewed the radiator as preventative maintenance mainly due to the pink milkshake concern but also just to avoid a failure on a road trip.
 
CowboyBob said:
I pulled the radiator, thermostat and upper/lower hoses this morning.

The thermostat is new OEM Toyota. It doesn't have 50 miles on it. The mechanioc was correct, he installed it at 12 o'clock. I put it back in with jiggle valve at 6 o'clock. I took a flashlight and small mirror on a stick and check hoses. None show any signs of kinking or delamination.

I took the radiator to the local radiator shop and they are checking it for clogs and defects. When I drained it, there was garbage that came out and the particles are about the size of a grain of sand. So I am hoping that the radiator is clogged and I can be done with this problem. I should know by the end of day.
Click to expand...

Yeah, I understand the thermostat position part, I guess what I was getting at is that you can run the engine without the thermostat to make the vehicle usable again. Running with no thermostat will cause the engine to run cooler. Might even be enough to at least resume functionality of your 4Runner until you can figure out the real issue.
 
New rad is $81 on RockAuto. If that doesn't fix it, my money is on HG. If it's HG, I'd just swap in a new (used) $500 motor. Troubleshooting issues like this can get expensive really quickly. Easier, (often) cheaper, and much less stressful to just swap out large components.

Also, and I'm sure this has been said already, but these motors can be a ***** to bleed and burp. The radiator funnels at your local Autozone screws directly on the rad and will gravity feed coolant to replace the escaping air bubbles. Could just be an air pocket.

Finally, when swapping out rad, run 100% distilled water and rad cleaner for a few days. You might even consider putting some mesh inline to filter out the remaining sediment. Though, I suspect R&R'ing the rad will get rid of plenty of the crap on it's own.
 
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absalom said:
Also, and I'm sure this has been said already, but these motors can be a ***** to bleed and burp. The radiator funnels at your local Autozone screws directly on the rad and will gravity feed coolant to replace the escaping air bubbles. Could just be an air pocket.

Finally, when swapping out rad, run 100% distilled water and rad cleaner for a few days. You might even consider putting some mesh inline to filter out the remaining sediment. Though, I suspect R&R'ing the rad will get rid of plenty of the crap on it's own.
Click to expand...

So you are recommending to use a long yellow radiator funnel or not?

Also, 'put mesh inline' -- can you repeat this in English? Put what in the radiator?
 
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It's Fixed!!!!!

The radiator was clogged. Guy at shop said it had half the normal flow. He flushed it out and it only cost $20. I also put the jiggle valve in at 6 o'clock.

Made the same 30 mile trip that I did yesterday and the temp never got over 189. It was in the 230's yesterday at the end of the same trip. So I would say that it is finally fixed.

Thanks for all the help I got from you guys!
 
CowboyBob said:
Ok here is an update.

I opened the hood and looked from the outside and could see the fan blade through the ac condenser and radiator. I blew it out anyway with a tool I made just for this purpose. It is an aluminum tube bent over at 90 degree angle at end. The water comes out so hard you have to hold it with two hands. I made it to blow all the chaff and grass seed out of my tractor radiator when I bale hay.

I let the car warm up to operating temperature and hooked up my scan tool so I could see exact temp. I then took it out for a long test drive at 55mph. The temp slowly rose about 1-2 degrees per mile. It hovered at 217 for the longest time, then started climbing again. It made it all the way up to 230, then I headed back home. The temp got up to 236 and when I turned in my driveway and stopped the car, it briefly jumped to 239 for about 10 second then gradually dropped over ten minutes (while idling in driveway) back to 199. I then turned off the motor. The whole time the temp gauge never moved. I drove it a total of 30 miles, the temp was about 15 degrees cooler outside from last time it overheated, so I think that is why I was able to go greater distance than last couple times. Also, the lower hose never collapsed or kinked.

I'm thinking maybe the fan clutch is no good. When I spin it with my hand as hard as I can spin it, it is not loose, but it will spin about 3 or 4 blades then stop. It never locks up all the way even when the motor was 239.

I'm also thinking about pulling the radiator and taking it to the radiator shop in town and having it tested. What do you guys think?
Click to expand...
On my 01 the clutch fan is always locked up when I first start it.
 
CowboyBob said:
It's Fixed!!!!!

The radiator was clogged. Guy at shop said it had half the normal flow. He flushed it out and it only cost $20. I also put the jiggle valve in at 6 o'clock.

Made the same 30 mile trip that I did yesterday and the temp never got over 189. It was in the 230's yesterday at the end of the same trip. So I would say that it is finally fixed.

Thanks for all the help I got from you guys!
Click to expand...
Thank you for the conclusion.
 
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