2008 5.7 overheating

Hello
Newbie here. I have 08 tundra 5.7 84k on odometer that had a leaking radiator for a couple months. This truck has never overheated before. Never past 1/2 on temp gauge. So I changed it last week with a Spectra Premium CU2994. The installation wasnt to bad we used same radiator fluid, since the frame recall in July.
I drive 2 miles to work and back and noticed no change in engine temp. So I had to get on highway and I noticed temp going up and up. It was close to H. When I got off highway it went back down some.
I let it cool and thought it was air in system. The heat works great. When motor was cold jacked up front and turned heat to high and squeezed top hose and some air bubbles came out and I thought I was good. Took it for a ride and it was heading towards the H again.
So I got frustrated and took it to my local mechanic and he replaced thermostat and fan clutch, did compression test on engine(all good) and tested coolant for exhaust gas and all came back good. No head gasket failure.
What you guys think? Bad radiator? Water pump was replaced years ago because of leak under warrenty.
Thank you

 

Make sure your radiator is clean through the cooling fins. Blast water in reverse to make sure it’s not clogged up bugs. If not, I would guess water pump.

 

Ok thanks

 

The crazy part is everything was fine until I changed radiator. No problem with water pump. No leaks. So fustrating

 

Water pump was changed at dealership about 8 years ago. Not sure if thermostat is OE probably not.

 

How would you test that? Or just try new one?

 

The mechanic said there might be some scale buildup in heads? Have you guys ever hear this before? I thought the Toyota red coolant was acidey

 

My guess is there's something up with the new radiator.

Did you maybe leave one of the plugs in it? Have a rag stuffed in there somewhere? Some kind of internal blockage?

 

When you changed the radiator did you bleed/burp it when filling the coolant? If not maybe there is still air trapped in the hoses which could cause your issue.

 

He said no flow in radiator possible scale in heads somewhere. I think new radaiator is no good. It did have a couple bent fins from shipping..

 

Yes filled it and squeezed top hose with heat cranked and front jacked up until i could not touch top hose.

 

I agree with others. I'd guess the radiator is defective.

 

Try vacuum bleeding the cooling system. Or have it done. With one of these:



That will eliminate any possible air bubbles and airlock.

If no different, something is up with the rad, or there is a blockage, like a cap in one of the ports, a rag left in a hose... ...not saying you screwed up, but throwing out possibilities.

 

Thanks I think I am going to have it towed out of

 

Well apparently there was a rubber plug stuck in lower hose near themostat. It came from new radiator. Can you believe it?
Thank god that is over.

 

Yeah I thought plugged heads was far-fetched. It worked before you got the new radiator. Glad you got it all taken care of. Stick around.

Man I need to proofread!

 

Yup. Stranger things have happened to far more normal people than me.

Glad it’s solved.

 

Thought so. It happens more often than you would think.

Glad you got it all worked out.

 

Thanks Taco. Do they usually put one up top? Didnt see (or look ) for these plugs. They should put a warning sticker on new radiator. It could have cooked the motor.

 

Usually a new radiator will have plastic plugs in the inlet, outlet, and trans cooler holes.

If you didn't remove the one up top (inlet) there's a chance it got pushed into the radiator upper tank. Not ideal but at least coolant can flow around it as it would just be sitting in the upper tank with no where else to go.

 

You think it will be ok?

 

If it is indeed in there you may want to try and fish it out but it's really not going to hurt anything because it can't go anywhere. If it's a plastic plug (most likely) it might break down after a thousand years and make its way thu the core.

Having said that, it would bug me that it's in there.

 

Ok I will take top hose off and take a look. Thank you

 

Steve and group. I have a 2007 Tundra with the 5.7 and 171,000 miles on mine. I have been having this issue for about 8 months now with no one being able to figure It out- including my Toyota dealer where I purchased the vehicle. I have never replaced anything but the thermostat and replaced the coolant by Toyota. I had it there yesterday and they redrained the fluid and bled the air out and replaced the radiator cap.
While driving home on the highway it was acting normal for the first 10 minutes and then the temp gauge went up to just below H and I put the heat on/ opened the windows to cool it down.
It does this when it's 80 deg out or when it's 20 deg out or if i am pulling my trailer around town even at a slow speed. The trailer weighs about 6000 lbs.
I am stumped as is Toyota.

 

Figure it out? having similar issues. Fan clutch going bad?

 

I had cooling issues before and I came across CSF to replace my radiator and so far so good!

https://csfrace.com/toyota-truck-suv-cooling-systems/