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Discussion Starter #1
Hello, my radiator has formed a hairline stress crack at the top plastic tank. I have read that this is a known issue with our OEM radiators, but I am sure mine was due to low coolant caused by a faulty rad cap. I am willing to invest the extra money and replace it with a full aluminium radiator.

Koyo and Mishimoto seem to be the preferred all-aluminium radiators discussed on this forum. A lot of the threads are older and report that Mishimoto quality was nowhere near Koyo, but that Mishimoto has changed quality over the last 5 years. In addition, the Mishimoto lifetime warranty and a collision warranty which is preferred. I cannot find any recent reviews on this and don't know to think if it is because they truly have improved, or if there is just a lack of reviews.

I have a manual IS300, so the transmission cooling piece is not required that autos need.

Any feedback would be appreciated, thanks!
 

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Hello, my radiator has formed a hairline stress crack at the top plastic tank. I have read that this is a known issue with our OEM radiators, but I am sure mine was due to low coolant caused by a faulty rad cap. I am willing to invest the extra money and replace it with a full aluminium radiator.

Koyo and Mishimoto seem to be the preferred all-aluminium radiators discussed on this forum. A lot of the threads are older and report that Mishimoto quality was nowhere near Koyo, but that Mishimoto has changed quality over the last 5 years. In addition, the Mishimoto lifetime warranty and a collision warranty which is preferred. I cannot find any recent reviews on this and don't know to think if it is because they truly have improved, or if there is just a lack of reviews.

I have a manual IS300, so the transmission cooling piece is not required that autos need.

Any feedback would be appreciated, thanks!
Koyo for track and durability. Mishimoto for warranty and less cost. Mishimoto will be fine for daily driving.
 

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anyone know if either one uses the stock style radiator cap? I ask because I have, a now defunked brand, mizu radiator. radiator cap is not stock style, but an older design which is hard to find in the OEM 1.1bar/16psi...


also the filler neck was higher and would rub on the hood sound deadening material. radiator itself works great, never seen +210F at a track day in 100F ambient temperature, except when I accidentally turned on the a/c

Sent from my Pixel 3 XL using Tapatalk
 

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anyone know if either one uses the stock style radiator cap? I ask because I have, a now defunked brand, mizu radiator. radiator cap is not stock style, but an older design which is hard to find in the OEM 1.1bar/16psi...


also the filler neck was higher and would rub on the hood sound deadening material. radiator itself works great, never seen +210F at a track day in 100F ambient temperature, except when I accidentally turned on the a/c

Sent from my Pixel 3 XL using Tapatalk
The cap is a different size. A shorter profile is available at any auto parts store.
 

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Discussion Starter #5
People recommend using a Subaru or Nissan rad cap to clear the hood where the filler neck is too high.

I am okay with going Mishimoto, but just wondering if quality has actually improved or if it was a rumor.
 

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ha funny thing, I'm using that currently but it still doesn't clear. it must be a mizu issue...

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I have installed the Mizu and Koyo and Ebay. The cap usually is the fix. Check your mount. Make sure it is seated all the way. You could re-drill and mount the saddle differently. But it should not come to that. Also make sure your hood is set right on latch height. If your front end has been damaged before. It may be the issue.
 

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I have installed the Mizu and Koyo and Ebay. The cap usually is the fix. Check your mount. Make sure it is seated all the way. You could re-drill and mount the saddle differently. But it should not come to that. Also make sure your hood is set right on latch height. If your front end has been damaged before. It may be the issue.
i have one of the first mizu's... the top tank is huge. I think they have since revised it. I'll look at the mount, maybe I can lower it some....

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Not sure if this is useful information but I put in an all aluminum koyo rad and I bought the specific koyo brand radiator cap to go with it (it was $30 extra btw). It fits exactly like the stock one did. No issues there at all.
 

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Discussion Starter #13
Thanks for the response guys, the Mishimoto seems about $50 cheaper and seems like the company will stand behind their product. Then there's the all aluminium Ebay specials for $100 too, but I'll refrain from those. Lol
 

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Mishimoto Rad Installed here with Mishimoto Cap - Installed originally with OE Hood and now Seibon - never had any fitment or rubbing issues at all. Purchased the Rad probably 3 years ago now. Cheers!
 
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