Having the Coolant flush and sparks plugs changed out this week.
Anything I should replace while im in there. I saw a video where a guys swaps out the temp sensor in the coolant line. Any need for this ?
The previous owner had atomic green in there and I would like to go back red.

 

What's the difference between "green" and "red" coolant? Since the color is just dye, I assume you have a particular make and type of coolant that just happens to be red. Which one, and why?

This article https://www.thoughtco.com/antifreeze...r-green-262558 suggests that some types of red coolant (Dexcool?) should not be used in a vehicle that once had green coolant. Whatever "green" signifies.

 

Well I was going to get the stuff from Toyota. As far as whats in it now I don't know.

 

If your hoses haven't been replaced in a while, replace them. Green coolant is fine since that is what came with the vehicle originally. The red coolant from Toyota will last much longer than the traditional green and is less prone to breaking down from what I understand.

 

Go back?
Why fix what's not broken?
Older Toyota's have green coolant like mentioned above^^^ . My first-gen has green and I'm pretty sure the gents that responded^^^ have green coolant in their trucks now.
Yes, red coolant is extended life, but how sure are you it will not shorten the life of your engine?

 

What vehicle are you working on and what engine does it have?

I would check out all of the coolant hoses. That includes all radiator hoses, heater hoses, bypass hoses, and throttle body hoses if equipped. If the coolant hoses are ancient and have lived their useful life, I would replace them.

You can test the thermostat while you are servicing the cooling system (Scope103 has links to Factory Repair manuals for this procedure). If the condition of the thermostat is unknown, I would just replace it with an OEM Toyota thermostat.

You can also clean any sensors or thermal vacuum switching valves that come into contact with coolant. These sensors can build up a scale on the surface and can cause issues if the scale is bad enough. RAD4Runner made a good write-up on the scale that builds up on his 1986 22R-E.

The different coolant colors exist to help distinguish different coolant formulations and thus different brands.

Toyota started using their factory "Toyota Red Coolant" in the early 1990s, so it is perfectly acceptable to use it. This post goes more in-depth into "Toyota Red" versus "Prestone Green" and other types of coolant. Remember that Toyota Red Coolant is not pre-mixed and will need to be diluted.

If you do decide to switch coolants, flush out all of the old coolant from your entire coolant system (radiator, engine block, heater core(s)). It would be a good idea to flush the cooling system several times. Filling the cooling system with just water and warming up the engine will help remove the more stubborn areas like the engine block and heater core(s).

I do not buy into the idea of extended service intervals. I just follow the factory maintenance schedule. To me, "extended life" translates to "better protection for the same service interval".

 

some areas to be careful:
Often the home mechanic changes coolant just to find they have cooling problems thereafter. most of the time, its because they justt emptied and filled the system.
This wont work.
Air needs to be purged, prefereably by filling to full, starting engine, letting it warm up a bit, then revving to 1200 rpm with a burping funnel in the radiator, or even better, having an assistant rev to 1200 and hold it there (pushing the air to the radiator top tank) and while the air is there, fill that void wiht coolant mix before the assistant lets the revs back. This will fill the system completely with fluid. if the revs are let to drop back before u fill the void, the giant air pocket goes back to the head to give you dramas for a long time to come.

Green and red mean nothing. Sure they represent something, but only for a particular manufacturer. You cannot say that just because its red in there now, u cant go green or vice versa. And the red wont break down the green or any of that garbage, its just that the manufacturers have to put that on the label because the red works differently to the green, so any dilution of the red, and the red wouldnt be 100% red and therefore wouldnt be 100% of what you just purchased and put in your car.

so work out what your radiator is made of, and get the appropriate coolant. if made of aluminium, find the coolant which is suitable for aluminium, and forget the colour.