Engine radiator Koyo or OEM BMW

Put a koyo rad in it and it’s been good to go.

If you go aluminum Koyo is the way to go.

I went with Koyo. CARid was the best price at the time. Been 7 years and no issues.

Radiators aren\u2019t supposed to leak. I have the same Koyo radiator in my NA Z, just put it in this past summer. I def do not have that leak.

Personally I’d be buying a koyo in full aluminum.

I went with a Koyo radiator, which is considerably better built than the factory piece, cost less than $300 with new hoses, and took maybe 2 hours, start to finish. Of course, I replaced the coolant at the same time.

just tested my new koyo hyper V at the track and that thing kept it rock solid cold, 180-203f the entire day but it was like 68 degrees out lol.

It happened to me once at a night time. I just pulled over, stopped the engine and started again after several minutes and everything was OK.

Edit: After reading other's comments, I realized that mine also related to coolant system. Some time after this incident I replaced radiator because of a coolant leak. May be this warning is related to that.

My first non warranty repair on my B58 540 was a $3k radiator replacement. That was at about 60k miles.

You need to replace that. Bmws run hot. Only fix