Coolant flush**RESOLVED**

So I did a coolant flush last night, ran 4 gallons of distilled water though the truck and everything went well till the end. I noticed the heater was not putting out heat like it was during the first and second flush. I proceeded to add the coolant as the last step and still not much if any heat. I let the truck idle for at least 30 mins with the radiator cap off and saw no bubbles in the opening. I continued to squeeze the hoses to verify there air was out of it. Again no bubbles. After researching the issue on this site and a couple others, some suggested raising the truck up off the ground. I did that, no difference. I then felt the hoses that run to the heater core, the ones before and after the heater valve were warmish. Not as hot as the radiator hoses. The long one coming out of the heater core was not hot at all. So my guess is the core is blocked and needs to be back flushed? Any help would be awesome.

 

I doubt the core is plugged,
The heater core lines are higher than the radiator cap so even when you fill the radiator to full it’s still not getting to the heater core.
You need the radiator fill kit funnel that adapts to the radiator cap that changes that by another foot higher

 

$31 Lisle 24680 Spill-Free Funnel, Standard Adapters, 11 x 7 x 7"es

https://www.amazon.com/gp/product/B00A6AS6LY/

local auto parts should have it as well.

 

I tried to use one of those. It leaked like crazy...it sealed around the radiator but where the funnel went into the adaptor it leaked bad. So I just poured the coolant in with another funnel.

 

If you had a cheaper version buy a lisle ones, they are better quality. Another option would be to elevate the front end drastically, be it parking on a hill or jacking the front end up. Have you just let the truck idle or have you revved the engine up and held it there for a little bit to really get the coolant moving?

 

They work, make flushing the system so much easier. I'd try the Lisle. Like everything else, there will always be cheap knock-offs. Make sure you're using the correct attachment piece. Not sure about the one you tried before but the Lisle comes with multiple attachment options.

Another thought is its not the funnel but something is seriously WONKY with your cooling sys and you have a real issue. Hopefully not.

you sort it out. G/L

 

I have not done that. I'll try another brand of the funnel and see if that works.

 

Mine was the SEDY brand.

 

Before you pick up the Lisle, maybe do another review of the process used with yours. Maybe you missed something.
Entirely possible.

System has to be burped good for it to function correctly. If you still have air pockets in there, going to cause funky behavior.

 

Possible. But I'm pretty careful when doing stuff. Plan it out and then execute it lol But I will go over everything tonight again and see if I did miss something.

 

How old is the thermostat? Will be interesting to see what you come up with. I recently did this on my 98 3.4 and didn't have any issue. It almost blows too hot now.

 

Here in another opinion that I did.

I added a prestone flush filler T at the input line of the heater core line,
That way you can top it off from there and this is the highest point now and you will have no air trapped

 

It all worked fine before the flush. The radiator and the T Stat were changed about 4 years ago. The temp gauge was working fine the whole time i was doing the flush. I am leaning to the cause being air in the system.

 

Kind of sounds like it. Sometimes the air can be pretty stubborn

 

If that stupid funnel would of sealed, I'm sure I would not be having this issue.

 

Probably right. Might of got a lot of air in there. Like someone else said jacking the front up will help. Leave it sit over night with the cap off. Sometimes this helps burp some of that air out.

 

I’ve never had leaking issues with the lisle model

 

Yeah. I'm thinking it maybe the after market rad that was installed years back? It leaked from the adaptor area. It was a mess!

 

i have a spill proof funnel and has worked on every car i own. might not fit my 2021 4 runner but i haven't had to flush the radiator in that thing yet.

 

How are you doing the flush? Did you have the heat control cranked to full hot and set it at the highest fan setting? I always flush with the rear wheels on ramps and refill with front wheel on ramps. Never had any issues. If all else fails then you can use a tool like the Airlift to pull a vacuum to refill. I've done both ways but pretty much just fill and burp now since I hate bringing out the compressor.