Is the 4.7L an iron block? Coolant dirty.

Drained the radiator prior to a timing belt service on my Sequoia. I assume this is an iron block? Coolant is a bit rusty.

 

Yes it is

 

So that coolant pretty normal if neglected?

 

I think part of the issue is that it's the wrong coolant. The coolant needed for the 4.7L is pink, not orange. Most of us use Zerex Asian blend.

 

Umm, that's not orange. That's brown.

 

Perhaps I'm color blind. Looks orangish brown from here. I'm not denying it might be rusty too. A good coolant flush is in your future. If you didn't already know, there are two drains on each side of the block for draining the coolant.

 

Looks like its contaminated, maybe with oil. Flush it, refill it with the right coolant, check again in a few hundred miles.

 

I didn't, just got it. What are the chances they would even budge on an 18 year old iron block?

 

Drains are brass. They always worked on my old Tundra. Make easy work of changing the coolant since you can add a hose to the drain and not make a mess.

 

I think this coolant started its life as pink Toyota or Asian coolant, but now, 10+ years later it is a soup broth of coolant and rust. If it were mine I'd drain, fill with distilled water, drive, drain, and repeat again. I would also try to reach the block drains and open those to try and get the rust flakes out of the system. Final fill with super long life and move on the the next project.

 

Super Long Life coolant (pink) for the late 2003 and newer. Standard Toyota Red coolant for earlier. Toyota did not back spec the newer pink coolant for applications that originally called for the red.

 

Prior to putting in the new (correct) coolant, you may want to consider running this stuff through the cooling system. I did it on my Miata (also a cast iron block) and it worked surprisingly well.

$28 CRC Thermocure Coolant System Rust Remover, 32 Oz, Rust Remover for Vehicle Cooling Systems, Removes Rust Scale and Deposits

https://www.amazon.com/dp/B00R74I5UY?_encoding=UTF8

 

OK I'll try to find the drain plugs.

 

Here is what the passenger side looks like.

 

My coolant is red, but I'm using the older toyota coolant you mix with distilled water. Now they add the water and charge you twice as much for the pink stuff.

I made the mistake of trying to drain mine via on of the brass cocks on the block and broke one off. The dealer tells me they never touch them.

 

Just dawned on me that this is the vehicle that you're working on the timing belt with the radiator still in place. Knowing that the coolant looks like that, I would replace the radiator as part of my cooling system refresh and restore. It'll make the Timing belt job so much easier and I would be leery of the radiator that's on there with that much rust in the system.

 

I'm not doing a concurs restoration, just maintenance. Will flush the system good and call it a day. I'm selling the truck and if the buyer wants to replace a radiator that isn't leaking or overheating, that's on him.

 

Ah, got it. Makes more sense now.

 

Is it possible they have been filling it with regular water vs coolant or distilled water. How did the thermostat look, can you add some photos?

 

Didn't take the thermostat out but will see after I get the water pump off.

 

If they put straight water in it, not coolant, yeah.

 

Looks like GA clay slurry to me, so I'm going with you're both right. You just lack the snark.

DING DING DING DING DING

 

If you have access to an air compressor, use a vacuum refill system

 

Yes, I have both.

 

What new coolant to use? I flushed out the block and radiator until water runs clear. I understand it was around 2003 was about when Toyota went from red to pink. Any reason not to use the longer life pink?

 

^^

 

The Toyota pink only comes 50/50, so if there is water left in the block from flushing, the freeze protection won't be close to -34F. Who makes a full strength pink?

 

It wouldn't be pink, it would be toyota red and they stopped making that a few years back. I did manage to buy 8 gallons of it for $10 each from a Toyota dealership in Keene, NH on a closeout sale.

 

So what do the Toyota dealers up there use? It's gets below -34F in some places.

 

I would assume the Toyota pink. Now you just have to buy twice as much as the red.