This is why you need an ODB2 scanner

Looks just like my Denso ordered from amazon. It's good. You're putting in a new thermostat, right? Mine seemed to work ok, engine as at 195-197. When i removed the stat I noticed it had scratch marks toward the top. New one keeps engine at 183-188 so old one wasn't opening completely.

Do watch your trans temps. Don't know where in Texas you're at but me in austin during summer (that's May to October around here) when I ran bypassed would see trans temps climb above 200 and towards 240 during normal (really easy) start/stop and hill country climbs. I didn't like the temps over 210 so ran in series with the new radiator. Now I don't see anything above 190 and more often runs about 170. Just passing along my Texas heat experiences. Luck. :cowboy:
 
OK so my new Koyo A1998 radiator came in yesterday. I ordered from here:
Toyota 4Runner 1996 1997 1998-2002 2.7 L4 3.4 Radiator 1640075180 KoyoRad | eBay

About 25 hours from placing the order to showing up at my front door, so that's good. It looks like they have a warehouse in Houston.

It looks like it'll fit fine, but I'm concerned about the plastic housing:
10if3if.jpg


Is this how the Koyo A1998 should be, or did I get an 'offbrand' offbrand radiator?

The stock radiator is metal.

Stock radiator has plastic caps. Not metal.
 
Looks just like my Denso ordered from amazon. It's good. You're putting in a new thermostat, right? Mine seemed to work ok, engine as at 195-197. When i removed the stat I noticed it had scratch marks toward the top. New one keeps engine at 183-188 so old one wasn't opening completely.

Do watch your trans temps. Don't know where in Texas you're at but me in austin during summer (that's May to October around here) when I ran bypassed would see trans temps climb above 200 and towards 240 during normal (really easy) start/stop and hill country climbs. I didn't like the temps over 210 so ran in series with the new radiator. Now I don't see anything above 190 and more often runs about 170. Just passing along my Texas heat experiences. Luck. :cowboy:

I have a newish t-stat in there already, so I'm gonna leave it. It was keeping me around 185 before the radiator went, so it works fine. Easy job if I ever need to replace it.

I'm in Houston (read: super flat), so I think that's the difference in our tranny temps. It's so flat that I take day trips to Austin when I'm in the mood for 'mountains'. How sad is that?
Houston. Come for the utter lack of scenery, stay for the humidity.
I kept O/D off then, but now I can really monitor next time I go, which is maybe twice a year.


Stock radiator has plastic caps. Not metal.
Huh, so maybe my broken one is not stock than. I assumed stock because I knew that it was old. I'm 95% sure it's metal, but now I'm doubting.
 
I have a newish t-stat in there already, so I'm gonna leave it. It was keeping me around 185 before the radiator went, so it works fine. Easy job if I ever need to replace it.

I'm in Houston (read: super flat), so I think that's the difference in our tranny temps. It's so flat that I take day trips to Austin when I'm in the mood for 'mountains'. How sad is that?
Houston. Come for the utter lack of scenery, stay for the humidity.
I kept O/D off then, but now I can really monitor next time I go, which is maybe twice a year.



Huh, so maybe my broken one is not stock than. I assumed stock because I knew that it was old. I'm 95% sure it's metal, but now I'm doubting.

You're radiator cracked at the plastic cap. That is discolored worn plastic. Looks stock oem plastic to me.

Elevation, weight and grade are huge factors. Ambient outside temp won't raise trans temps drastically like towing up a major grade, full load at high altitude. That's why I didn't eliminate my stock trans cooler.
 
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My wifes dads Hemi Ram has a gauge that shows 140 mark on low, 190 mark at middle and red at 240 mark. His gauge actually does fluctuate. I was very surprised when I did his water pump, radiator and thermostat.

He actually told me he brought it into a shop because he thought it was overheating. It never hit the red. they told him up to 230* is normal and not to worry until it hits the red. I told him if it gets near that mark to shut it off and call me.

It fluctuates so much that it will lower when running the heater as it cools the heater core.

Well see, there you go, though. That was an easy way for them to make some money. He thought there was a problem and brought it to the shop. He thought it was hotter than it should be. They could have at least looked at it, and 'tweaked' a few things. Easy work and easy money.
That's just the shop being lazy and sneaky. Almost sounds like they were 'recommending' that he overheat his engine because they wanted to sell him a rebuild.
What are the odds that he'll go back to that shop if his engine fails due to overheating because he allowed it to get to their 'normal' temps? He knew there was a problem, they said it was fine, and he turns out to be right? They probably shot themselves in the foot with that and lost business, both a cooling 'tune-up' and engine rebuild. Hell, if they have that in writing, he could probably sue if he wanted.
I don't know. Just my .02.


You're radiator cracked at the plastic cap. That is discolored worn plastic. Looks stock oem plastic to me.

Elevation, weight and grade are huge factors. Ambient outside temp won't raise trans temps drastically like towing up a major grade, full load at high altitude. That's why I didn't eliminate my stock trans cooler.

Well geez that shows how brittle my broken one is. It honestly sounds like metal when tapping on it.

I don't tow, Houston is flat, and 80' above sea level. I think I'll leave it bypassed. Haha.
 
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Got the new Koyo rad in today. Not too hard, just messy.
Only 1 snag: the mounting hole on the lower passenger side didn't fully line up. I had to use my oscillating tool with a plunge cutter to widen the hole on the 4runner slightly.
54adc1c4fc30abd048b740fb5a021f9a.jpg

I made sure to simply thread all 4 bolts before tightening any down to avoid issues like this, but this was too off. Eh whatever, this was not an OEM rad.

On my test drive, temps not above 188 :)

Sent from my SM-G900V using Tapatalk
 
Do watch your trans temps. Don't know where in Texas you're at but me in austin during summer (that's May to October around here) when I ran bypassed would see trans temps climb above 200 and towards 240 during normal (really easy) start/stop and hill country climbs. I didn't like the temps over 210 so ran in series with the new radiator. Now I don't see anything above 190 and more often runs about 170.

I've been having issues with the transmission getting this hot when not moving fast enough to have the air flow cool the oil. Going to switch it to inline soon which sounds like it'll take care of that issue. Just put in a new radiator as well.
 
This is the exact reason why I bought an Ultra gauge. I set an alarm to go off for the coolant temp at 210 degrees.

I've never seen my coolant temps above 195 for what its worth.

Hmm....mine idles at 189 and runs 202-204 degrees and it's a new Toyota thermostat they installed on my new motor.
 

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