chenderson

Ok. Alright. Geez. I've searched for a SIMPLE ANSWER to this VERY BASIC question EVERYWHERE, and can not find one!

Hi, guys. I have a 2006 IS 250. It does NOT have a cap on the radiator directly. It's on a separate manifold above the engine.
The upper radiator hose goes from this manifold to the radiator, and a smaller tube also goes from there to the plastic spill-over/expansion reservoir tank.

BUT... WHERE EXACTLY do you pour in NEW COOLANT when (re)filling for the first time (say, after a flush or whatnot)?
Do you remove the METAL CAP on the manifold and pour the 9.1L (2.5gal) of coolant into there? Or....
Do you remove the PLASTIC CAP on the plastic reservoir/expansion tank and pour it in there? I don't think so on this one!
But it just doesn't FEEL right pouring it into the metal manifold as most of us are used to having a cap on the radiator itself instead and pouring coolant into the radiator directly.. even though, ya, there is the upper radiator hose where coolant will eventually go ... but in the manifold there is also a tiny hole that goes to the rest of the system (engine). I'm not sure if I'm suppose to pour there and have coolant got into the system of a cold dead, pre-start engine. I just wanted to be 100% sure as to where to put/pour a whole new 1-2 gallons of new coolant! That's all. It'ss s basic, right? LOL. I feel like such a noob. But I've not found any answer on Internet at all .. thus far

BACKSTORY: Driving home, I started to see small amount of steam coming from under hood. I pulled over immediately, and saw some liquid. Pinkish, watery more than oily. I couldn't tell actually if it was more oily or watery, so wasn't sure if Tranny, PS or coolant. Come to learn I have a sealed Tranny, and rack steering (someone told me it even uses magnets to glide!); so that ruled out those two. Not tranny fluid. No power steering fluid (which in most other cars is actually ATF fluid), Anyway, so after narrowing it down, I researched cooling system problems and discovered that I use the reddish "pink" coolant. So, bingo on that. Also, this car hasn't had a coolant flush/refill in its 10 year life, so it's original OEM. And then I ran into a video that talked about radiator caps, and boy, what a work of engineering marvel these caps really are!! LOL.
I took mine off, and the hot pressure shot some fragment up at me and poked my eye out, neighbor had to call 91...NO!! I'M JUST KIDDING!!!... :P
I took my radiator cap off and lo & behold, the middle rubber plunger piece WAS MISSING!! Double Bingo on THIS! But, however, I have NO IDEA where it went, and it really could only have slide down the upper radiator hose into the radiator, as there is NO WAY it would fit into the tiny hole in the manifold leading to the engine cooling system. I took off upper hose and tried to finger the radiator (kinky!) but couldn't feel or get the plunger. I figure screw it, leave it. I'll deal with it later, AFTER i replace the faulty radiator cap with a new one and refill my system with coolant. BTW, I'm going to be using Zerex Asian "pink", and I have ALREADY drained the radiator only from the bottom petcock, and took out the plastic reservoir/expansion tank and emptied & cleaned it. I HAVE NOT AND WILL NOT BE FLUSHING the entire system. I figure (from my research on coolants) that it will be Ok to mix this Zerex with the original Toyota OEM still in the system/engine & remaining on the walls of the radiator. Anyone else disagree??

So, I replaced my faulty radiator cap, and bought 3 gals of Zerex Asian. Emptied the radiator, and I'm ready to pour.

But WHERE DO I POUR ???

Also, I do know about causes of the symptom where the thermometer gauge (in the dash) bounces from hot back down to middle over and over.. (i.e., system gets hot, pressure finally gets so high that it opens up/pushes past the faulty cause (thermostat, water pump, a clog, etc.) and coolant flows and cools system). SO, my point is, if I still get this symptom after replacing the cap and refilling system -- which I WAS indeed getting this symptom on the way home after half the coolant had exited my system due to the bad radiator cap -- then it JUST MIGHT BE that rubber plunger from the old faulty cap that got stuck inside the radiator, blocking/clogging the flow. I hope not! I hope this symptom will DISAPPEAR once I put the coolant in.... BUT..... however....... the question still remains:

How do I do it?? Where does the coolant go on a full refill?

Such a simple thing. I feel so dumb. :/ :P

Thanks in advance, guys!

chenderson

P.s.- ya, the car is 10 years old, and has 165k miles. And I know it's best to do a full system flush, change thermostat, change radiator, check water pump, etc. etc. blah blah BUT, before you guys start advising me on this, I JUST SIMPLY NEED TO SIMPLY KNOW WHERE TO SIMPLY POUR THIS SIMPLY COOLANT!! LOL. Thanks!

In the meantime, awaiting a SIMPLE answer, I will go ahead and check the thermostat in upper radiator hose area. I found a GREAT 2-minute video on it. It's from this site called.. something like.. ClubLexus... :P :P :P
Thanks guys. !!!

327steam

Watching the mechanic that just put a water pump on my IS350, you add thru the metal cap, let the car run and keep adding once hot to the same entry. But someone else may chime in.

Mrfix

If your coolant system needs large amounts of coolant (e.g. after a drain and flush), you would fill it from the metal cap on the manifold. The overflow reservoir (plastic tank) can be used for for top ups.

Pour the coolant into the Radiator via manifold coolant cap. It will flow through the upper hose into the radiator to fill it. The following funnel makes it much easier to bleed the air out of the system.

https://www.amazon.com/EPAuto-Spill-Proof-Radiator-Coolant-Filling/dp/B01I40ZQWE/ref=sr_1_2?ie=UTF8&qid=1483124456&sr=8-2&keywords=coolant+funnel

After filling the radiator as much as you can place the funnel on the coolant inlet and fill it so as the coolant level goes down when the rest of the system is filling it will fill from the funnel. Make sure you turn on your heater also.

It is very important that you get all the air out of the system. If you don't have the funnel above make sure someone stands over the filler inlet and adds coolant as the level goes down. Check youtube for some videos.

I would suggest replacing the thermostat also if you can. Run water through the whole system and do a good flush. Then refill.

chenderson

Thanks guys. And thanks for reminding me about "burping" and suggesting I check the thermostat. I'll be doing that now.

Thanks again!