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2016, 5.7, 75k
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Discussion Starter · #1 ·
Hello, this is my first post here and i read great things here. Hence, seeking some advice and insight to overcome an issue.

tundra 2016-5.7 , 70k miles and i live in Dubai.
My engine overheats when i take her on off road driving, dune bashing or sitting long time at traffic ..now the point is it does not heat up when i drive, how much stress i give or throttle to climb dunes it does not overhear.

when we take a break and when car on idle after a drive temp starts to climb..when i rev on idle i can see the needle comes down or i need to start driving again and temp comes down.

New radiator, water pump, clutch fan, belt, and many more recent changes.

i am really not sure why? No major symptoms of head gasket , no black smoke or milky oil on cap
I am thinking to change the coolant temperature sensor next before i consider head gasket change if that is the cause ?
Any inputs and advice is greatly appreciated..thanks in advance 馃檹
Wheel Tire Car Vehicle Hood
 

Registered
2016, 5.7, 75k
Joined
9 Posts
Discussion Starter · #2 ·
Hello, this is my first post here and i read great things here. Hence, seeking some advice and insight to overcome an issue.

tundra 2016-5.7 , 70k miles and i live in Dubai.
My engine overheats when i take her on off road driving, dune bashing or sitting long time at traffic ..now the point is it does not heat up when i drive, how much stress i give or throttle to climb dunes it does not overhear.

when we take a break and when car on idle after a drive temp starts to climb..when i rev on idle i can see the needle comes down or i need to start driving again and temp comes down.

New radiator, water pump, clutch fan, belt, and many more recent changes.

i am really not sure why? No major symptoms of head gasket , no black smoke or milky oil on cap
I am thinking to change the coolant temperature sensor next before i consider head gasket change if that is the cause ?
Any inputs and advice is greatly appreciated..thanks in advance 馃檹 View attachment 156148
Hello, this is my first post here and i read great things here. Hence, seeking some advice and insight to overcome an issue.

tundra 2016-5.7 , 70k miles and i live in Dubai.
My engine overheats when i take her on off road driving, dune bashing or sitting long time at traffic ..now the point is it does not heat up when i drive, how much stress i give or throttle to climb dunes it does not overhear.

when we take a break and when car on idle after a drive temp starts to climb..when i rev on idle i can see the needle comes down or i need to start driving again and temp comes down.

New radiator, water pump, clutch fan, belt, and many more recent changes.

i am really not sure why? No major symptoms of head gasket , no black smoke or milky oil on cap
I am thinking to change the coolant temperature sensor next before i consider head gasket change if that is the cause ?
Any inputs and advice is greatly appreciated..thanks in advance 馃檹 View attachment 156148
 

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2016, 5.7, 75k
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Discussion Starter · #3 ·
Update! Changed coolant temperature sensor, problem still exists..grr grr

Running out of options, hope your expertise can give me some peace of mind..

Pls help
Thanks
 

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How about the thermostat? Sounds like is is not opening. In the old Fords we use to drill a couple of 1/4 inch holes in the thermostat so water would flow a bit before the thermostat got warm and opened. That is an old trick we learned with model "A's". Easy replacement process and not expensive part.. Just drain radiator in to a bucket below thermostat level and install a new one. Pour the same fluid back in the radiator. You could put the old one in a pan of water on the stove and when the water boils see if it opens. If I have to take it off, it's getting replaced. Chap
 

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Discussion Starter · #5 ·
Hi Chap, i replaced thermostat 2 months ago, but not toyota鈥ts mishimoto thermostat鈥

Thinking if i should go back to Toyota genuine 鈥hat do you think if i drive a little without the thermostat to see if i have the same issue?? Is it recommended ??
Thanks foe ur inputs 馃憤
 

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There are a couple of things that you need to make sure of. The side of the thermostat with the temp. sensor points outwards, toward radiator. There is a little pin in the rim of the thermostat, a "jiggle valve" that needs to be on top when the thermostat is installed. I have seen thermostats put in backwards in old Ford Flathead engines. When this is done it takes longer for it to warm up enough to open. This may be the issue??? Easy mistake to do.
If it is in correctly test it with hot water as I suggested earlier. It won't hurt your engine to run for a bit without one but you will have to create a gasket or use Form-A-Gasket so it doesn't leak. But if it is not overheating when "working" I don't think this will help you figure it out. With the engine warmed up carefully open the radiator cap and see if you can see the coolant flowing? It has to be a flow issue.
I live in Arizona and on the hottest summer day (105f) my Tundra, 4.7 never overheats even when idling for prolonged periods with a/c running while I wait for my wife while she is shopping...LOL
Here is a You Tube Video on replacing that thermostat. Good Luck, and as always, "Enjoy the adventure"... Chap

 

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If it doesnt heat up when moving couldnt that also be an air flow problem? I know you said you changed fan clutch but can you be sure its actually engaging when needed or is it always just free wheeling? I wouldnt have a clue how to check it but it does seem odd that the problem only exists when when not moving.
 
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If it doesnt heat up when moving couldnt that also be an air flow problem? I know you said you changed fan clutch but can you be sure its actually engaging when needed or is it always just free wheeling? I wouldnt have a clue how to check it but it does seem odd that the problem only exists when when not moving.
A boss of mine had a bad clutch fan on a late 60s early 70s GM vehicle, yeah this was in the 70s too and I'm that old, anyway when you started the car you could see the fan lagging behind the engine speed and you could actually stop it from spinning by hand. If you try to stop the fan from spinning be mighty careful my friend.

Nice looking truck by the way!
 

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Discussion Starter · #9 ·
Chap, thanks for the link and explanation on the thermostat. Yes, will consider this to be checked again and will keep you posted..thanks

will take a look again on the clutch fan
Cheapskate & MT thanks

i have recorded when it heated and the fan speed and how the gauge does down when i throttle it while the car is parked ..
Tried to upload but unable to in this forum..
 

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My guess is the fan clutch too. When your truck is off and it has cooled down can you spin your fan by hand? When it is hot can you freely spin it by hand with the vehicle off? I believe there should be a lot of resistance and I have seen them where all the fluid is gone and they spin freely.
 

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Discussion Starter · #11 ·
My guess is the fan clutch too. When your truck is off and it has cooled down can you spin your fan by hand? When it is hot can you freely spin it by hand with the vehicle off? I believe there should be a lot of resistance and I have seen them where all the fluid is gone and they spin freely.
when the engine is cold , i have tried it and it spins little freely, i can feel it will not rotate full circle when i spin it by hand鈥ut spins freely

i have not tried when engine hot and off!!
when engine hot and off does it spin freely or it should not ?
sorry for being dumb , not mechanically strong and bought the car 2 months ago..
 

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when the engine is cold , i have tried it and it spins little freely, i can feel it will not rotate full circle when i spin it by hand鈥ut spins freely

i have not tried when engine hot and off!!
when engine hot and off does it spin freely or it should not ?
sorry for being dumb , not mechanically strong and bought the car 2 months ago..
as your engine heats up the fan clutch should hold and not spin. When my truck is cold it doesn't spin at all but it does move if you try and move it.
 

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Discussion Starter · #14 ·
Any updates Hihad?
Update: i got the car from the workshop and drove it for 3-4 days and currently i am on travel 鈥ill give it a good spin , stress the car when i am back home..

i did do some aggressive driving for few days on 1st , 2,3,4 gear on high speed and stopped after driving it did not heat up so far. Stayed at dash gauge 50%..
Mechanics have changed the AC fans to bigger fans( front of the radiator ) and sealed the area around the radiator so that the air from the fan directs to the radiator.
I have told the workshop everything what we have discussed here ..further, i assume they have completely taken off the thermostat..i need to reconfirm that when i am back in Dubai..
The change i see now is, during a normal morning drive the dash temp sits at very low and rises upto approx 30%鈥 before it rises after few mins to 40-45% and sits there鈥
Another thing i checked was after a ride the top radiator hose, now i can squeeze them by hand ..before it was feeling the pressure on the hose was unable to squeeze.
Clutch fan checked and working fine..
I shall share few images when i return home from my travel..
If above symptoms are alarming pls let me know..
Thanks all for some great advice and i am learning 鈥
 

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The engine runs rich to heat up faster so the longer it takes to heat up, and if it never gets to normal operating temperature, I would think it would always burn more fuel. Running hot is not good but running cold isnt great either. I would keep an eye on the fuel economy and see if you notice it dropping.
 
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Discussion Starter · #16 ·
The engine runs rich to heat up faster so the longer it takes to heat up, and if it never gets to normal operating temperature, I would think it would always burn more fuel. Running hot is not good but running cold isnt great either. I would keep an eye on the fuel economy and see if you notice it dropping.
hi Cheapskate, something interesting you are bringing up鈥ctually i did not drive for long after this fix , hardly 5-6 days..:
Previously my dash indicated shows 19-20L/100km鈥.one week i drove it showed 22-23L/100km..
I have not measured fuel consumption accurately yet coz still a new user 鈥
I read in this forum that people get much greater mileage鈥
I guess even 20L/100km is also a lot right?
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20/100 is brutal mileage. I sold mine but I only got that in the winter time and thats because of the cold, excessive idling, and my short drive to work. In the summer I would average on the display would show around 14 or 15.
Your numbers could be in part due to the big ass tires and lift you have but it still seems pretty high to me.
 
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Discussion Starter · #18 ·
20/100 is brutal mileage. I sold mine but I only got that in the winter time and thats because of the cold, excessive idling, and my short drive to work. In the summer I would average on the display would show around 14 or 15.
Your numbers could be in part due to the big ass tires and lift you have but it still seems pretty high to me.
i was thinking the same, its really adds pressure on the wallet haha..i knew it would consume due to 5.7 and was prepared for it coz the intension is to build a sexy, nice looking truck to enjoy some off road adventure. At this rate i am struggling to drive more often on road, highways due to tank just gets empty quickly.
First will work out the thermostat/engine temp to be accurate ..will install back the thermostat is they have removed it.
I had the bank1 timing retarted issue also, where i replaced bank 1 cam shaft sensor and also replaced all 4 cam shaft solenoid sensors.

also installed AFE air intake system鈥park plugs etc鈥
May i humbly ask What other areas i would need attention to improve running conditions..
Thanks so so much
 

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I've actually heard that removing the T stat means the vehicle always runs cooler. Since it keeps flowing it never sits long enough to get properly warmed up, its constantly flowing through the rad getting cooled off. Nihad says his truck isnt getting up to normal temps so that would support that theory. And again, if its never getting to proper temp, its always going run rich trying to overcome that problem.
I'm no expert on any of this stuff but if it were me I would put the thermostat back in and look for a new mechanic. They might not sell a lot of Tundras in Dubai but I'm sure they sell Toyota's. A cooling system is a cooling system, they're all pretty much the same and a good mechanic should be able to figure it out.
 
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