Ideal coolant ratio?

This is true. You're supposed to change the cap like every 5k to 10k or something like that, but no one ever does and most of the time the cap works forever, but if you're running hot you should change that.

 

I was seeing temps of about 205 in Houston traffic and neglected to change the cap despite changing the coolant.

I blew a head gasket that fall. Not saying it was the direct cause but it likely contributed

 

Could have been the cap, could have been something else, but a cap is cheap compared to a head gasket lol

 

Think I'm going to go pick up a radiator cap from Toyota this afternoon lol. Haven't changed mine out since I got the truck 50k miles ago, doubt the PO ever did it either.

I did have Toyota do a coolant flush on the truck a few years back, dunno if maybe they put a new cap on as part of that service or not.

 

That's the first I've ever heard of being "supposed" to change the cap at regular intervals. My '17 4Runner has been in the dealer 3 or 4 times for its free 5k mile services, and they haven't said anything about that.

If it's leaking, there will likely be residue, but if it's not leaking, I see no reason to replace it, although I can see it as a cheap an easy thing to replace. But other things (admittedly more expensive) are more likely the causes of running hot; water pump, radiator clog, etc...

 

Thermostat was changed just a couple years ago with an OEM one. Rad appears to be in good shape, no plugs or bent fins. The funny thing is, I have a vague memory of thinking I noticed higher coolant temps after my flush and fill with 60/40, so I suspect at least part of that is due to the higher % of coolant. I'll do a 50/50 next time and report back. Do you all think another flush is necessary at this point? Current batch has been on there 1.5 years with ~16,000 miles on it.

Right now (in March) it doesn't go above about 200 on the hot side in stop and go traffic.

 

Only caveat there is the pre mix isn't compatible with the concentrate, or so I read somewhere. I'd have an easier time trying to hit the 50/50 ratio with concentrate and distilled water, I think.. Simple because there will still probable be some concentrate in my system.

Guilty of overthinking things. I thought this was a support club for people like me??!! HAHA

 

This is on my list for sure. I just need to decide between OEM or one of the TRD offerings. One has a psi rating of 18.5 and the other is 21 I think. Stock is like 13 psi or something isn't it?

Any of you running TRD rad caps?

 

Oh it definitely is. We just all have different obsessions, and we all like to make fun of each other.

But yeah, again, over thinking it. Drain it, fill it with 50/50, any remnant 60/40 isn't going to make it blow up.

 

In one racebike it would overheat the moment I got back to the pits and lost the movement of air through the rad. It was clockwork. Added the correct ratio of water wetter and same conditions next practice 30 minutes later the overheating was gone. Never had an issue ever again until after a motor swap I was out of WW and ran it anyway. Overheating was back. Borrowed a bottle from another racer and the issue went away again. My cooling system was right at the limit of its cooling capacity so my other option was a rad swap (which was illegal for my class).

One thing to consider is if you add water wetter to ANY system with a thermostat the thermostat will always try to modulate the temperature. Unless you have already experienced a situation outside of the limits of your thermostat you shouldn’t see any change in the sensor readings. On the other hand if you have a 180* thermostat that is working properly and you are reaching 230* then adding Water Wetter may show you an improvement in your temp sensor readings.

 

I usually wouldn't change a cap unless it looks bad or something is wrong with the

Yeah changing the cap is just one of those things thats recommended but won't cause an issue until its actually bad and leaking coolant. I'm not really sure about the service interval for a cap anyway, some old mechanic told me that. You're also supposed to run a higher psi cap if you go to high elevation, but most people never have an issue with a stock cap

Edit: now that I think about it, the old man must have been talking about older vehicals needing the cap to be changed all the time

 

Yea maybe
I would think if the coolant reservoir is always between the F and L you’re cap is fine!

 

I'm running the regular one and it's fine.

 

I can definitely see that. Here are a lot of things necessary for old cars that just aren’t needed for newer ones.

Of course, our 1st gens aren’t exactly spring chickens anymore, lol. I’m sure there are things on ours that aren’t need on newers ones.

 

TRD radiator cap?? lol

Toyota has gotten pretty good with their marketing schemes, haven’t they...

there is no real reason to buy a trd radiator cap, or even, really, a higher psi one. I’ve driven up over 12,000 ft with my stock cap, and it’s fine. If your cap isnt leaking, there isn’t much of a reason to replace it, let alone “upgrade” it with a trd cap.

 

50/50 coolant concentrate to distilled (or tap water) is all I have ever used.I'm more worried about freeze protection. Test it with a Prestone type tester to verify freeze and boiling point. 50/50 Toyota red concentrate will give -34F freeze and 265F boiling protection. 60% gives -62F and 270F, 70% -84F and 276F. That's from the chart on the container. My Prestone tester scale agrees with Toyota 50/50 data. On modern vehicles, I always use OEM brand coolant. There are too many incompatible chemistries to take chances now. I will top up with all makes all models premixed coolant in a pinch.

The cap can be tested with a pressure tester to verify it is holding the pressure range that it should be. If you are not sure, change it. It's cheap insurance. The boil over point is increased by a known amount for every extra pound of pressure. Caps are not so much of a problem now as they were when you had to open them regularly to check the coolant level.

Most important though, is making sure the radiator/ condenser fins are completely clear of bugs and debris, the coolant level is correct, electric fans, if any, are operating when needed, fan clutch is operating correctly and the grill is not obstructed with lights, bars, and other add ons. This assumes the hoses are not soft and collapsing,the thermostat is operating correctly and the radiator is not internally restricted by corrosion. None of these items should be ignored for long. Engine damage can occur as a result of even one overheat.

The above applies to street driven vehicles. Race applications have their own requirements.

 

Just found that the PO was running something Green in the radiator. Reservoir is basically empty. Would love to get some Toyota Red in there (likely running something above 50/50, maybe 60/40? I live in one of the coldest spots in the lower 48 - Gunnison, CO). In the meantime, any suggestions for Green stuff I can add to the reservoir to keep things happy till I can do a coolant/radiator flush?

Thanks for the suggestions in advance.

 

Walmart store brand (Supertech) is green and cheap. The worst thing about green is that it's not long life. Every 2 yrs. isn't something most of us want to do. The gov't doesn't want us doing it either.

 

Thanks @cruxofthebisquit ! I'll take a look at our local Wally World. We also have one of the country's smallest Wal-Marts; and it's not 24 hours. If not, there are at least 3 other auto parts stores in town.

 

I'm just south of Modesto and run 50:50

I normally don't see temps above 190-195 even in traffic in the summer. However, I'm not exactly running the stock Toyota colling system.