Overheating issue

2004 tundra sr5 4.7L v8. No engine mods. New thermostat. New radiator. No coolant leaks, pressure checked. Engine starts to overheat in 80F+ weatherafter 20 minutes of driving. If I turn the heater on, the engine cools off within 2-5 minutes.

 

Water pump? or Thermostat stuck or in wrong. Air pocket in the cooling system.

When the truck is COLD remove the radiator cap and start the truck, once it warms up a little CAREFULLY Look at the coolant in the radiator and see if its moving around. that will let you know if your water pump is working.

 

Did you do the work? OEM parts? The thermostat has to be installed a specific way.

I'm trying to remember but I believe this part has to be on top when installing. I'm not sure if this would create any issues or not. I just remember reading this at the last minute as I was installing mine.

 

All oem parts. Did not do the work myself, went to a mechanic who owns his shop, and used to work for toyota as a master mechanic, all very legit.

Brought truck to a toyota dealership yesterday, they called me two hours later saying “leaky water pump, bad thermostat”.
When I informed that that the thermostat had just been replaced and the coolant system passed a pressure check (no leaks) they backpedaled. I then had my mechanic fax over all the records of everything he’s done, and now they’re trying to say that they’ve pinned it down to the fan clutch.

B.S.

They’re playing a guessing game.

I called toyota corporate, they escalated it for me. They gave me the option of having the dealership management contact me or go to anther toyota dealership for a second opinion. I am waiting to hear from the management. Tomorrow’s the 4th, so I expect that it’ll be Friday before I get a call.

 

Fan Clutch. Then when the Engine is COLD start the truck. the fan should be pretty loud and in 30 seconds to a min it should become rather quite if its good.
Mine does.
With the motor OFF spin the fan by hand see if there is a little resistance, if its good.

 

I’ve already done that... stops at about a quarter turn.

Which is why I called corporate. Because this dealership wants me to play carnival games with my truck.

 

Shouldn't the guy that just did all the work be responsible for this new problem? If it wasn't overheating before it seems like he should be trying to identify what went wrong.

 

When I bought the truck, both head gaskets were blown. My mechanic fixed that.

This issue isn’t new. I believe it is what caused the blown head gaskets before I bought it.

 

Seriously, outside of this issue, truck runs like new. No check engine, all power, love it

 

Ooohhhhhhh. Wonder if one of the heads might be cracked,

 

Standard practice with head gasket repair is having the heads checked for cracks while they are off... but yeah I guess it's always a possibility.

Fan clutch is generally for slow driving. The ram effect of driving on highway should keep the temps down.

Not sure what else there'd be besides the components listed already...

 

The thermostat is upside down I bet, and not letting coolant pass through. Mistakes happen to everyone, unless your mechanic is one of the lizard people or something. Have him double check.

 

Yeah, sounds like coolant isn't moving through the system until you let it flow into the heater core. Could be something as simple as a bad tsat from the factory. You can check it by putting it in a pot of water on the stove and bringing the water to a boil to see if it opens.

 

I had a fuel pump go bad on my parents Dodge mini van.
I drained the tank, dropped the tank,put the new dealer fuel pump in,put everything back together.
Van would not start.

The fuckin new fuel pump from the dealer was bad.
Had to do the whole thing twice.

It is possible to get a bad part once in awhile.

I'd pop out that thermostat and see if it opens up when you boil it on the stove. And make sure it's in correctly.

 

Sounds like you have air in your cooling system. You have to bleed the air out

 

Anything fixed?

Our Tundras self burp if you pull up an incline. When changing my coolant, it took about 3 test drives and incline revs plus hand burping the lines.

The next day I did the top off to the F line in the res after the engine came up to full temp.

Curious how OP temp drops when the heater is on. I’d look into the new thermostat or maybe a clog in the block? How bad did the flush look?

My rad water was gnarly dirty about 5 years ago when the OEM rad failed.