Overheating anytime I’m towing.

Hi there,

I don’t understand what’s happening to me/my truck.

Anytime I tow literally anything, the Coolant reads:
Peak: 105c
Average: 90-95c
Minimum: 89c

07 Taco 4x4 DCLB, Towing PKG.

I had this happen before that ruined my camping trip. We replaced the thermostat when we returned to town.

Today, Ive been towing a 12ft enclosed aluminum trailer.
Her dry weight is 1,500lbs.
When wet it’s approx 3,000lbs.

It gets particularly nasty if I’m not highway driving.
At a stop light it creeps up to 95-98c. Until I rev it up to 3,000rpm for the duration of a stop light, when I let go, it drops to 90c.

Yes the temps creep a bit when going up a hill, that’s fine, but on flat ground. Grr!

I have already done a coolant flush, thermostat replacement.

There is a few times that the coolant overflow tank is filled!

I’m at a loss here. Any help is appreciated.

 

You need to open the rad cover open and inspect the rad for mud and dirt. You can’t always wash the rad out until you can get between rad and condenser.

unfortunately this has the potential for early headgasket issues.

 

Check your fan clutch

 

air bubbles in the system?

 

Please advise or any links to information on how to do so.

Yes, when the heater core is running I do hear an initial toilet flush.
When the overflow tank isn’t full, there is no bubbles, but when it’s full to the rim there is a very slight trickle.

No I’m not losing coolant.
No it’s not coming out of the exhaust.
No it’s not a head gasket, I checked with the magic coloured dye thing, 4-6months ago.
Yes, I’m aware that the toilet flushing sound is indicative of air in the system.
sorry not trying to be rude, I know these questions will be asked.

Copy. I will attempt a super flush.
I hope to god it’s not a head gasket.

 

The magic dye doesn’t really work with mild leaks. You do the test at no load in neutral but the condition happens under heavy load.

hopefully it’s a dirty rad or a fan clutch etc

 

fin cleaning and fan clutch are the next 2 steps
when you did the flush how dirty was the old stuff, I'm thinking blockage in the rad if what came out was bad

 

Patient: It hurts when I do this.

Doctor: Don't do that.

(Sorry, fully aware that my answer is useless but couldn't resist. I do hope you get it sorted)

 

I'm not a towing guy but at a quick glance some of those numbers aren't wretched, the 90-95 C is about 200 F which doesn't surprise me carrying a load .

If you haven't already, there's a good resource here on the general subject. Not sure if it delves into your situation re towing temp but it's worth a shot.

https://www.tacomaworld.com/threads/the-tacoma-towing-bible.4031/

 

What device is giving you those temp readings? And what does your OEM temp gauge show when this is happening?

 

For the Fan Clutch, see this tread:

https://www.tacomaworld.com/threads/overheating-at-low-rpm-thoughts.674697/

 

Usually temps come up at a stop cuz there’s significantly less airflow going through the system that’s already hot. Not unusual.

 

Yes I’m hoping either.

Mechanic reported nothing too dirty, but I did have to put in an emergency coolant mix with water as I was out in the trails. It went in slime green, it came out, slightly browner than slime green.
But that was months ago.

Today it’s still pink Ish,

I’m using a OBD Bluetooth thing, that goes to fusion app, as highly recommended by this fourm.

I’m told that the Dash temp gauge is nearly useless. But to answer, it has been in the Center most of the time, until it goes past 100c, then I will see it climb.

Yes I Agree, but it should not happen while I’m at a stop or standstill traffic.

But close to overheating? As in creeping to 100c?

 

Sounds like a small head gasket leak

 

No

 

Update:
This morning as I was reversing the trailer to a buddy’s place.
(Approx 15min) the temp went up to a peak of 105c.

I had to shut off, as from my understanding. I no longer have any thermal headroom, incase something somewhere is hotter than the sensor is reporting.

After work today, I drove around the block vigorously with the rad cap off.
The overflow tank went from close to overfilling, to the “low mark”.

Here is a photo of the rad cap @Bishop84

After driving vigorously spilling coolant everywhere, Ive noticed while I’m parked typing all this, the sensor is reading 90c steady. (About 10min parked.)

But when I accelerate to 2,500rpm for 5 sec then let go. The temp went from 90c to 85c.

 

How long have you had the truck? Do you know if the cooling system has been maintained? I’m thinking poor or no maintenance, or possible wrong type of coolant used. Using the wrong coolant and/or lack of maintenance can cause sludge, rust, and other deposits to build up which leads to clogged radiator. The truck is 17 years old , I’m not surprised you have cooling system problems. That sludge on your finger is throughout the radiator and the flow is restricted. I’d just bite the bullet and get a new radiator and consider replacing the water pump if it is the original.

 

Standard or auto transmission? Auto you should be towing in 4 not D .

 

Is that even over heating?

Sounds like pretty normal temps

 

I'd say +1 to this. Sometimes it's worth really diagnosing the specific problem before launching the Parts Cannon at a situation. This is not one of those times. From the vague glimpses in the above photos it sure doesn't look like the overflow is pink antifreeze. And judging by how dark the power steering reservoir looks, it doesn't appear routine maintenance has been quite so routine. On top of that, just the fact that it's a 2007 I'd be replacing the radiator, water pump, and various hoses/lines as maintenance items just by age. And if an OEM thermostat wasn't used the first time, take it out and put in an OEM unit (or at least an Aisin brand which is basically the same thing).