Filthy cooling system

[T4R2014]

I ordered a Denso from Amazon for less than $110 and opened the box today. It was made in China. The box was wrapped in bubble wrap, but that wasn’t enough- the overflow fitting on the radiator neck was broken off and laying in the bottom of the box. So, off it went for a return. The foam stayed on the corners, but the side of the box was caved in slightly, with a small hole where the fitting punched through before breaking.

Mine’s a 1999 w 230k that I just picked up. Very clean, rust free vehicle. I’m doing brake and suspension repair/upgrades and purchased the new radiator as PM. It looks like it has the original radiator. It’s filled with the green stuff, but I drained some into a white bucket, and it’s very clean. Previous owner had good records of regular fluid changes and flushes.

I’m now considering disconnecting the transmission coolant lines at the radiator and just going to a B&M or similar trans cooler, and leaving the oem radiator in place since it has no known problems and looks very clean internally. I’m thinking flushing the green out and going with the Zerex Asian coolant.

I’m new to the 4runners, but reading a lot of info on this forum that is very helpful.

Thoughts?

I wouldn't dick around with bypassing the trans cooler if the radiator is new. The factory design does a better job at getting the ATF up to temp faster. Frankly I think it's one of the reasons that these transmissions last so long. I would recommend getting a cooler installed inline if you plan to tow often or spend a lot of time at low speeds in 4lo.

 

[AntleredRuin]

Hmm. I have one of those Taiwan Denso's and I haven't had any issues with it. It's about 4 1/2 years old now. It spent it's first two years in Phoenix and last 2 1/2 years here in Wisconsin. It seems to be holding up great but I'll definitely keep a close eye on it now.

PS. From everything I've read, the Zerex brand coolant is great and you shouldn't have any issues with it. I used to be a purist and bought the OEM coolant. I also noticed that walmart is now selling Valvoline "toyota/lexus" coolant with "zerex technology". I have no clue what that means.

I usually buy the actual Zerex brand "asian" coolant that is specifically for toyota/lexus at advance auto. I buy two gallons at a time online, use one of their coupon codes and it comes out to be like 10 bucks a gallon.

I did some research on this a couple years ago in another thread and found that 'Valvoline with zerex technology is the same as just 'Zerex'. Both are made by Valvoline, and both are Zerex. Just a different container, I guess specifically for Wal-Mart.
$11 at Wal-Mart, any time of day or night, no coupon. It's a good deal.
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[96RedRunner]

Can someone still explain why my original 3rd gen has insanely good heat compared to my other two?.

Since the heart of the system is the same across all years, changes made to later models using servo motors.
My 01 gets hotter heat output wise than 96, have never accessed 96 heater core have on 01 because PO had dogs.
01 Evap and heater core were clogged, not anymore.
You have any idea what condition the evap and heater core are in for air flow?

 

[jgue467]

...
I’m now considering disconnecting the transmission coolant lines at the radiator and just going to a B&M or similar trans cooler, and leaving the oem radiator in place since it has no known problems and looks very clean internally. ...
Thoughts?

As T4R2014 said, don't disconnect factory trans cooler - it will overheat during Texas summers in stop/go traffic, hills and/or towing, ask me how I know.

Instead do as you planned, replace the radiator (a Denso lasted this long, should do it again) with the factory cooler hooked up and add an extra external cooler if you like, they help.

Enjoy that Runner! :cowboy:

 

[T4R2014]

Since the heart of the system is the same across all years, changes made to later models using servo motors.
My 01 gets hotter heat output wise than 96, have never accessed 96 heater core have on 01 because PO had dogs.
01 Evap and heater core were clogged, not anymore.
You have any idea what condition the evap and heater core are in for air flow?

Not a clue on this 1996. The heater core has been through a lot, lets put it that way. I bought the truck with a blown head gasket and the coolant was poop. Replaced the engine and flushed the system but there may have been more hiding in the heater core than I thought. I wanted to do a backflush, but with the weather I was working in this was not an option.

 

[T4R2014]

As T4R2014 said, don't disconnect factory trans cooler - it will overheat during Texas summers in stop/go traffic, hills and/or towing, ask me how I know.

Typical bad forum advice that has been passed around over the years IMO. Too many shadetree mechanics trying to outsmart the Japanese engineers.

 

[AntleredRuin]

I ordered a Denso from Amazon for less than $110 and opened the box today. It was made in China. The box was wrapped in bubble wrap, but that wasn’t enough- the overflow fitting on the radiator neck was broken off and laying in the bottom of the box. So, off it went for a return. The foam stayed on the corners, but the side of the box was caved in slightly, with a small hole where the fitting punched through before breaking.

Mine’s a 1999 w 230k that I just picked up. Very clean, rust free vehicle. I’m doing brake and suspension repair/upgrades and purchased the new radiator as PM. It looks like it has the original radiator. It’s filled with the green stuff, but I drained some into a white bucket, and it’s very clean. Previous owner had good records of regular fluid changes and flushes.

I’m now considering disconnecting the transmission coolant lines at the radiator and just going to a B&M or similar trans cooler, and leaving the oem radiator in place since it has no known problems and looks very clean internally. I’m thinking flushing the green out and going with the Zerex Asian coolant.

I’m new to the 4runners, but reading a lot of info on this forum that is very helpful.

Thoughts?

I'd say replace the radiator. Clean or not, if it's original at 230k, it's probably going to die soon. Mine split at the top around 170k, and it looked very clean and I maintained it.

That being said, there will be no problem with bypassing the radiator tranny cooler, with you living in The Woodlands. I live in Spring, TX and I've run bypassed for over 2 years. Never seen temps above 167 (measured using Torque Pro). Even in stop-and-go traffic in August.
For those not aware, The Woodlands is 160' above sea level and the biggest hill in around 100+ miles on any direction is the freeway on ramp.

Maybe don't bypass if you live in hill country (or tow, as stated above) but even daily driving here will be just fine.

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[PLC 83]

Thanks to everyone for the advice. Once I have the repairs and maintenance done, the vehicle is going to the 4 corners area to be my fish/ski/mtb etc vehicle. So, it will see mountain usage, but no heavy rock crawling anticipated.

I think I will order another Denso radiator and hope it doesn’t arrive damaged. Maybe Rock Auto can package one better than Amazon. It sounds like the replacement Denso units may have issues with potential tank end leakage after a few years, but I’m not hearing any problems with the trans cooling loop. So, if I go with the new radiator, I will use the oem style trans cooling loop. My thought with using an aux cooler was for if I was keeping the original radiator, so that a cooling loop failure would not take out the transmission.

 

[T4R2014]

Thanks to everyone for the advice. Once I have the repairs and maintenance done, the vehicle is going to the 4 corners area to be my fish/ski/mtb etc vehicle. So, it will see mountain usage, but no heavy rock crawling anticipated.

I think I will order another Denso radiator and hope it doesn’t arrive damaged. Maybe Rock Auto can package one better than Amazon. It sounds like the replacement Denso units may have issues with potential tank end leakage after a few years, but I’m not hearing any problems with the trans cooling loop. So, if I go with the new radiator, I will use the oem style trans cooling loop. My thought with using an aux cooler was for if I was keeping the original radiator, so that a cooling loop failure would not take out the transmission.

Haven't seen a pink milkshake failure with a newer aftermarket radiator. There's better things in life to worry about. Leave the factory cooler. Once you have to worry about what driving conditions affect ATF temps, the vehicle is no longer a functional vehicle to me. The factory cooler simply works to spec.

 

[AntleredRuin]

Thanks to everyone for the advice. Once I have the repairs and maintenance done, the vehicle is going to the 4 corners area to be my fish/ski/mtb etc vehicle. So, it will see mountain usage, but no heavy rock crawling anticipated.

I think I will order another Denso radiator and hope it doesn’t arrive damaged. Maybe Rock Auto can package one better than Amazon. It sounds like the replacement Denso units may have issues with potential tank end leakage after a few years, but I’m not hearing any problems with the trans cooling loop. So, if I go with the new radiator, I will use the oem style trans cooling loop. My thought with using an aux cooler was for if I was keeping the original radiator, so that a cooling loop failure would not take out the transmission.

I'd recommend eBay for the radiator, specifically this listing from this seller:
Radiator 221-0508 Denso For Toyota 4Runner 96-02 3.4L 2.7L Gas | eBay
I bought this from this seller in 2017 and it was on my doorstep less than 24 hours later, with free shipping. Your mileage may vary, though; shipping technically states a few days.
It was packed solidly, a box within a box with foam in between.

Perfect fit, Denso, no issues so far and it's been nearly 2 years.

 

[nc-grayson]

so what are you all doing with the dozens of gallons of drained water after so many flushes?

 

[T4R2014]

so what are you all doing with the dozens of gallons of drained water after so many flushes?

My neighbor's dogs seem to love it!


Just kidding. I have these giant plastic cooking oil containers my dad keeps around. probably 10 gallons. The guys at autozone are too stoned when I walk past them to the oil recycling. It is coolant with oil after all.

 

[AntleredRuin]

Might not apply to your location, but you're allowed to dump coolant down the drain in Houston.
It's considered ok, environmentally.

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[T4R2014]

Might not apply to your location, but you're allowed to dump coolant down the drain in Houston.
It's considered ok, environmentally.

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I never checked, but I know the storm drains run to a creek a few yards away. Plenty of animals around there. Didn't want dead deer all over so I didn't.

 

[Wedgy]

If you are considering adding the trans cooler:
YouTube

 

[catrains]

I am the original owner of old vehicles . I do the work . on my 96 and 2000 I never use any drinking water only distilled ....when I do the antifreeze I open all the drain plugs and use a water hose and I drain out all the coolant and water from the block. I then put my finger in the T stat goose neck port and no mess.. reason is no drinking water ...only 35% distilled and 65% antifreeze..

I never had this mess when I stopped using drinking water ..

 

[ToyotaBrah]

Might not apply to your location, but you're allowed to dump coolant down the drain in Houston.
It's considered ok, environmentally.

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What? Please send me a link of where the city of Houston has allowed the disposal of coolant into a storm drain or sink. And no, it's not considered okay environmentally.

Even in our underfunded city, they still have a designated hazardous disposal site where they accept all kinds of fluids, including coolant. I'm certain Houston has at least one site, if not more.

 

[AntleredRuin]

What? Please send me a link of where the city of Houston has allowed the disposal of coolant into a storm drain or sink. And no, it's not considered okay environmentally.

Even in our underfunded city, they still have a designated hazardous disposal site where they accept all kinds of fluids, including coolant. I'm certain Houston has at least one site, if not more.

I know I read somewhere about allowing dumping but I can't find the link. However, according to this .gov site, Houston considers coolant to be 'non-hazardous' and therefore allows it to be taken out with the normal trash. Pour it back into the gallon jug and throw it away. Which in my mind means it'll be taken to the city dump, will leak into the ground, and there you go.
Household Hazardous Waste: A Guide for Texans - TCEQ - www.tceq.texas.gov


There are places around that do take coolant for recycling, however.

 

[Mudeprived]

Same deal with mine. Many flushes and drainings later and it is still the same. I fill it with fresh fluid and it looks orange in the radiator then I drain it a week later and it is a clean pink. I gave up on doing anything about it.

Pop off the TB and look at the coolant passages. They will most likely contain alot of orange buildup. I had to scrape those clean.

 

[gamefreakgc]

Might not apply to your location, but you're allowed to dump coolant down the drain in Houston.
It's considered ok, environmentally.

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For reals? Do people in Texas know that antifreeze kills animals and aquatic life?

My storm drain runs to a local creek. In the summer I like to fish in that creek and take my kids there. I kind of like having the fish stay alive. I hope people in Texas realize that too. If you're going to dump antifreeze, at least do it down a toilet or sink since that goes to a wastewater treatment plant first.

EDIT: Just saw the post about throwing it away. That's a little bit better, since at least it goes to a dump. But once it rains that coolant is going to find its way back into the waterways.