Overheating while towing

Well,

We just finished up a little cold late fall camping trip and I noticed I had some issues. Here's what's at play:
2006 Tundra 4.7 with 221K miles towing a 4900lb 23ft travel trailer
new OEM radiator cap July '21
new Denso radiator & hoses Dec '21
new Tstat Dec '21

Have noticed being low coolant a few times and haven't been able to nail it down. While towing this last week for about 160 miles, only 1 grade of which was pretty small but was averaging about 55-60mph most the trip except the last 30 miles being like 15-30mph. Anyways, when we arrived and I stuck the camper where I wanted I noticed my temp was pretty high but not in the red. Filled the radiator the next morning with about 1-1.5qts of water (all I had) so it didn't seem like it was THAT low on coolant but who knows. Overflow reservoir was very low as well. I noticed a bunch of coolant all over the driver frame rail and wheel but couldn't pin it down to a leak anywhere. Got home today from camping and noticed that my overflow reservoir is full and bubbling/boiling.

I pulled an oil sample and it looks fine.
Temp gauge when I got home was normal as well.
I haven't peeked at the water pump ( honestly don't know where it's at)
Radiator top tank crimps look fine, there is some coolant by the cap but I think that's spray from the overflow tank making a mess at speed.
There is oil leaking from the driver side valve cover which is on my list of To-Dos but I wouldn't think that would affect this.
There is also oil buildup in front of the oil fill tube which I'm not sure where that would be coming from but again don't think it's related.
I wonder if it's just too much for the truck to pull or if my radiator is blocked or if I have another issue that I am too stupid to realize. Any ideas, thoughts, or help would be much appreciated. All this in the midst of my wife's Sienna having a cracked upper oil pan and now getting a timing cover reseal and the works.
Here's some pictures cause I know you guys love pics!

 

Crackie towed my 4,800lb, 24 footer just fine. Took that shit like a champ.

The most glaring issue that I personally see, is that you don't know where your water pump is?!?!?!? Get to know your rig. Intimate knowledge of your vehicle could save your life one day if stranded on a trail, or the bush.

Overflow reservoir boiling, or... overflowing? Your engine should be running around 180 degrees Fahrenheit. Your water, and definitely your coolant should NOT be boiling in a pressurized system such as your cooling loop.

The splatter pattern looks consistent with at speed overflow reservoir... overflow, and the air blowing the coolant around.

 

A partially blocked radiator you’d most likely feel it getting warmer at the bottom and less resistance when squeezing the top hose when the t-stat opens.

 

Can you add a photo of the bottom of your radiator cap. There was a member on here a few months ago with a similar issue and the cap was missing the bottom half + he had air in his coolant system

https://www.tundras.com/threads/i-could-use-some-help-sourcing-a-coolant-leak.145284/

 

I'm suspicious of the cap as well, it is near new and OEM so I wouldn't think so but it's definitely possible. I only got 3 or 4 years out of a replacement cap on my camry, though it was aftermarket.

 

Clutch fan? If unaware of water pump location, when was the timing belt last serviced and by who? Should have gotten a new water pump then.

 

Just do a clutch fan test to completely rule it out.

when the truck is hot, turn it off and go try and spin the fan by hand. It should spin a few inches, a 1/4 turn at most.

If it spins freely it's done and you need a replacement.

 

You can also test the fan by putting a piece of paper on the front of the radiator while the truck is running and the fan should hold it in place. If it falls, the fans doesn’t have enough pull. Assuming you can easily get to the front of the radiator. I’m not sure if 1st gen layout.

 

I know the rough location but didn’t dive in yesterday to check. Had to unload all the camping stuff, deal with 3 kids and get dinner going. As you grow up Noah, your responsibilities grow as well haha. I wish I had time to tinker and be a mechanic but honestly my time is worth more with my family.

I’ll check that later today.

The radiator cap looked fine but I’ll probably replace it just to make sure.

I checked the timing belt about 2 months ago. Looked great. It was done by the PO with 183K.

I’ll check when the wife returns with it from work.

There’s a trans cooler in the way but may be able to do this option as well.

 

I really like the depth of knowledge and experience available here.

 

While it’s obvious that coolant is coming out of somewhere near the overflow tank, I’d suspect the fan clutch too. Mine was super super weak.

Another thing I’d like to add is that the stock temperature gauge has been pretty inaccurate for me. Now that I’ve got a scangauge, I’ve found that the needle’s “normal” position could mean anything from 175-210°. I can’t say for sure if this has been just my truck or not though.

 

It is - my transmission temp gauge (OEM dash one) when read via the obd2 port - hits the middle and stays there anywhere from 130 - 250+ (I have no idea how high it will go and still stay in the middle - never pushed it beyond that). But that is a huge range to make everything seem ok when on the upper end we know its not OK (add external trans cooler + fan = 200 Max trans temp). Luck all and use those odb2 ports for real temp monitoring.

 

Guess you may be right. This is after a shortish 10 minute drive but engine was up to temp.
https://youtube.com/shorts/bhlrSJE-OFY?si=kSq6Pr9GREHZbrpJ

 

That thing is done. This is what you need: https://www.rockauto.com/en/moreinfo.php?pk=1947784&cc=1357938&pt=6812&jsn=1016

 

She dead.

you're just not pulling enough air for those stressful towing situations.

 

hoping that's all my issues and that my radiator is still fine. I'll swap that out when I get it. Thanks for all the help guys.

 

Well I went to Napa and got a fan clutch installed today so we aren’t down a vehicle. Cleaned everything up and ran it for a few minutes. Air blown by the fan is way stronger now. Everything seemed good so I parked it…..and the saga continues. Looks like it’s leaking from the top tank possible of the radiator so I’m waiting on a new one now. Hard to see it but there is a pool at the bottom of the radiator too. So annoyed.

 

How old is that radiator? I mean 10 yrs is a good time as far as preventative to replace them especially if they've turned color from gray to brownish. Look at it this way - it gave you plenty of warnings to prevent something far worse like an over heating engine and then cracked heads costing thousands to replace or repair. Luck all.

 

Only 2.5yrs old

 

Denso or like "good" brand?

 

Denso. Pretty mad it gave out so soon but my overheating may have hurt it. I don’t know. Either way there really isn’t a better radiator option so the truck will have to sit in the driveway until I get the radiator.

 

cars/trucks are pain.

our rads are pretty whack honestly. If I can find an all aluminum replacement I'll do it. Welds are stronger than pinch's. I think.....lol

 

I think emptylord went with an all alum replacement custom build. Kyoto or mishimoto I thought. Just not worth it to me for the money.

 

I think it was CSF or champion.

 

I think you were low on coolant & it got hot. But i'm pedantic & would consider more than a qt low alarming. Check your oil filter cooler hoses on the driver side of the block.

 

I’m going to guess it was damaged in transit, and it finally reared its ugly head.

 

Probably right.