Engine Coolant Question

Post #7

https://www.tacomaworld.com/threads/coolant-reservoir-bubbling-and-filling-up.437255/#post-12676768

 

I'm just going to wait until Friday and see what my friend's shop says. They haven't screwed me yet.

 

With over 300K miles, any coolant component is liable to need replacing.
Water pump
Thermostat
Fan clutch
Radiator
Radiator cap
Hoses

It would be prudent to check for a bad head gasket. Generally, there are 7 ways a head gasket can fail and only one of the fails leads to oil in the coolant - so not finding oil in the coolant does not mean your head gasket is in the clear. Two other ways deal with coolant: compression leak to coolant, and coolant to outside leak.
https://haynes.com/en-us/tips-tutorials/7-different-ways-head-gasket-can-fail

Only a leaking heater core will affect engine cooling. A blocked core will not affect coolant temps because the engine does not rely on the heater core for cooling. That said, if coolant temps go up, setting the heater to high can sometimes aid in bringing down the temps.

BTW, I'm a fan of universal coolants - I've replaced the OEM coolant in all my Toyota/Lexus products with SuperTech anti-freeze at 100K. No need to waste your money on red or pink stuff.

 

Antifreeze in itself is NOT a good coolant. It has to be diluted to the proper amount with water to do a good cooling job. It is about a 50/50 mix. I once, before knowing this, put too much coolant in a car I owned and had overheating problems.

If you overdid the coolant mix, that may be the source of your troubles.

 

Just buy the 50/50 mix and be done. My old 3.4L needed straight coolant with water mix.

 

I used the 50/50 premixed Zerex for Asian cars. It was about 17 dollars for a gallon jug at O'Reilly.

 

So...no one is going to address the dead toad?

 

My wife found it all dessicated next to hole in the ground at a house we were looking at when we were looking to move.

 

So it ended up on the dash board? I swear I'm not poking fun, I can't sleep now without the back story.

 

Well, I do have this as my TRD sticker on the rear side panel of my truck.

 

OK, it's all coming together now! lol

 

This why I have my truck....to go find these cool critters.

 

UPDATE

They found no leaks in the system. They pressure tested for the easy stuff and found nothing.

They checked the trans and did not find the strawberry shake.

They also tested for head gasket leaks and found none.

WTF!?!

 

This is just a suggestion, but did they happen to pressure test the radiator cap? I've seen caps not hold pressure and begin to vent pretty easily. Not enough to let water just boil out, but enough to be a nice steam vent. With the size of our cooling systems it wouldn't take long to drain down. A coolant system not holding pressure will also overheat quickly and easily. That could explain the temp climbing into the red after a few minutes. Just a thought.

 

^^ True. They no longer sell a radiator with a new cap on it.
^^ You have to supply the cap yourself.

 

They suggested get a new cap. So I will.

 

The cap would be a cheap place to start. In my opinion I would use only a OEM radiator cap. I was involved in the auto parts industry for 7-8 years and I never saw an aftermarket radiator cap better than the OEM's. Such a simple part, but the OEM are always high quality in my experience.

 

I just bought a new cap for mine from the dealer. It was about $14. They ordered it and had it for me the next day. With so much crap made in China these days, I didn't want to trust the aftermarket stuff with such a crucial part.

 

Thank you all for the input guys!

If there is any further updates I will post it.

If you dont hear anything more from we will just assume it was a bad rad cap.

 

OK. This was weird.

While driving tonight, uphill at slow speed I noticed my temp gauge starting to climb again.

I pulled over, popped the hood, and the cap to the overflow tank was completely uncapped. And the tank was full (just below the fill spout) of coolant. I resecured the cap and looked around the engine bay. I saw a good sized wet spot on the top of the silver skid plate. And it appeared there was some "spray residue" from the possibly overflowing uncorked tank.
The rad cap did not appear to have leaked at all. However, there looked to be air being sucked into the overflow tank from the capped off drain at the bottom of it. I say this as there was a steady stream of air bubbles coming from that capped off drain plug.

I cut my trip short. I headed back toward home (about 60 miles away). I made one stop and checked the system again. This time the coolant tank was not bubbling and it was down to the "fill" line. I checked the inside of the rad and appeared to be missing some coolant. I sealed the rad back up, squeezed both hoses a few times and then turned the car back on.
I drove home and the temp has not gone over 1/2. Even sitting on the side road as I type this post into the web.
Tomorrow morning after its cool again I will recheck the rad and overflow tank.

Questions:
Besides the cap just not being properly secured what else could have caused it to pop off and fill so full?

Is it possible the overheating was due to the cap not being securely on the overflow tank and likely sloshing coolant out the tank?

Should I worry about the air being sucked into the system through that drain plug at the bottom of the overflow tank?