Time for a cooling system refresh - OEM radiator still the way to go?

[0-60motorsports]

I have an NRF along with new Genuine everything else and my car gets hot on track. I'm probably going to try something else soon enough and move on from the NRF. Maybe a Koyo, maybe a do88.

I was going to order the Do88 yesterday but then i noticed its a triple pass like the CSF and i just dont want to face the headache of the bleeding procedure etc. At this time I would LOVE to buy the KOYO only if someone is willing to provide me dimensions and weight of the box and ship it to my forwarder.

[sev]

im coming due for a cooling system refresh. everything is still intact but its now 20 years old.

I cant find a list of hoses that need to be refreshed and I havent done the m3 before. Obviously the expansion tank, the hose to the expansion tank up top, maybe the bottom one and the two radiator hoses and the radiator. My waterpump and thermostat are fine.

What hoses should I make sure I get?

[PSUEng]

I was going to order the Do88 yesterday but then i noticed its a triple pass like the CSF and i just dont want to face the headache of the bleeding procedure etc. At this time I would LOVE to buy the KOYO only if someone is willing to provide me dimensions and weight of the box and ship it to my forwarder.

Anyone know where in the US to buy the KOYO? I dug around, but couldn't determine this; maybe I missed something.

[chentwoten]

Anyone know where in the US to buy the KOYO? I dug around, but couldn't determine this; maybe I missed something.

I just did the entire cooling system on my vert which was getting hot in 100+ deg weather; all OEM except for the Koyo radiator. You're looking for p/n HH422675; I shopped around and ordered it from Pit Stop Tuning (no afilliation) and found a 10% coupon bringing the total to <$500 shipped. It was drop shipped from Turn14 (wholesale distributor), so I'm assuming that's where most sites are listing it from. Hope that helps.

[0-60motorsports]

I just did the entire cooling system on my vert which was getting hot in 100+ deg weather; all OEM except for the Koyo radiator. You're looking for p/n HH422675; I shopped around and ordered it from Pit Stop Tuning (no afilliation) and found a 10% coupon bringing the total to <$500 shipped. It was drop shipped from Turn14 (wholesale distributor), so I'm assuming that's where most sites are listing it from. Hope that helps.

Thats great! I was going to order one but then my tech sent me a video of my 22 year old OE radiator being flow tested and its perfect and looks new too.

[Bry5on]

Thats great! I was going to order one but then my tech sent me a video of my 22 year old OE radiator being flow tested and its perfect and looks new too.

Just keep an eye on your end tank seals after 22 years..

[0-60motorsports]

Just keep an eye on your end tank seals after 22 years..

Good idea! Will do. Thank you.

[beemer_guy]

im coming due for a cooling system refresh. everything is still intact but its now 20 years old.

I cant find a list of hoses that need to be refreshed and I havent done the m3 before. Obviously the expansion tank, the hose to the expansion tank up top, maybe the bottom one and the two radiator hoses and the radiator. My waterpump and thermostat are fine.

What hoses should I make sure I get?

This is late but if anyone else needs this, I just refreshed every hose on mine, the only things remaining which I'll probably do next year are the expansion tank and the radiator. Parts are as follows:

Diagram references in bold + italic

Hoses
Cooling System Water Hoses
Upper radiator hose (with the bleed screw) (#1): 11537830716
Lower radiator hose (#3): 11537830715
Coolant Hose (expansion tank to water pipe) (#6): 11537830713

Water hoses/Water valve
HVAC Heater Hose (inlet) (#1): 64216902678
HVAC Heater Hose (Core to valve) (#3): 64216902679
HVAC Heater Hose (outlet) (#5): 64216902680
(these three were a dang pain to replace)

I also replaced a few other things since I wanted to check/replace the thermostat and coolant pipe, and there are various O-rings and sensors you should replace if you are refreshing the entire system otherwise they will be your next points of failure.

Sensors
Cooling Systems Water Hoses
Auxiliary Fan Switch (coolant temp sensor) (#4): 13621433077
Temperature Sensor (#18): 13621433076

Waterpump - Thermostat
Thermostat (#5): 11531318274

O-rings
Cooling System Water Hoses
Water Pump O-ring (#12): 11537830712 X2

Waterpump - thermostat
Thermostat O-ring (#6): 11531318402
Coolant Pipe O-ring (#8): 11537830710 X2

I believe that's everything, although I also replaced the coolant pipe (11537830710) which was probably unnecessary but the shop that replaced the thermostat last absolutely mobbed the entire area with RTV unnecessarily, and it took me too long to clean just the thermostat housing and didn't want to spend extra time cleaning the pipe.

I highly recommend replacing the O-rings for the metal hoses that go to the water pump, I think mine had a leak at some point and you could see the brown gunk around the area, and the old O-rings were stiff. It did not take that long to clean the pipes and replace them. The rubber hoses I had technically all were ok, but the O-rings in every single one of the connections were also stiff and I didn't want to risk putting the wrong sized O-ring and finding out my mistake later.

The last additional thing I did since I already had access to the area was drain the engine coolant via the engine block drain plug and swap it out with a new one (07119904539 + washer [07119963225]). Even with all that I had coolant coming out of every hose I removed, making a fun mess to clean up, just FYI.

If anyone has any questions I've got pictures of every single location for the water hoses/etc., hope this helps.

[0-60motorsports]

I’m still planing to order a koyo regardless. Didn’t think of the plastic end tanks

[PSUEng]

I grabbed one.