Engine radiator Koyo or OEM BMW

Koyo N flow. Only rad you’ll ever need. Even though you want to keep it “stock” the OEM style plastic crimped end tank design is a time bomb and should be avoided.

Koyo is definitely one of the best available as a stock replacement. They make 2. The n flow is a little harder to fit but is “better”.

Koyo rad is top tier, as I’ve used them on all my drift builds.

The first radiator at the dealer was a genuine BMW part# 17111436060. Mine has lasted well.

Replaced with original.

24 years is good for me.

The stock piece lasts well over a decade in my experience. That's more than enough for me for a part that fits and functions perfectly.

Held out for the koyorad and it's the same size as stock and went in with no troubles.

I have a koyo radiator in my na6 with stock fan on it and it has no clearance issues. Probably wasn’t necessary for me currently but I’m going turbo after I spend more time driving it na so figured why buy twice and just went for the koyo.

N54 335i - 200k miles radiator upgraded

The white tank has never been the issue for me, leaks are always in the radiator frame surrounding that tank. Somewhere at the bottom, probably where the lower hose goes. The plastic is brittle crap and it develops micro-fractures that become cracks over time.