Hello, R53 aficionados. My M40 runs warm/hot as most Minis do. It does not overheat and the fans work. However, I live in Texas where the Devil vacations every June and VRBOs for four months. I am looking for a higher capacity radiator that will help keep my little 4-banger cooler. Who has installed a radiator that functions better than the OEM version? If so, please reveal the name/model number and detail your experience. Thanks.

 

@MiniManAdam runs a Mishimoto. Tagging him for replies. I use the same brand on my Z32 with great results and beyond excellent customer support.

 

What...exact temperature...is considered "hot" ?
Since they don't actually have a readable gauge in the dash.
My JCW doesn't even make it to the half-way mark in the semi-useless gauge in my 06, not even during 106° summer days, in SoCal. What number does half way up the scale represent, I have no idea, but I would not consider that...hot, by past experience with numberless gauges.

Mike

 

If you have an actual coolant temperature gauge, what temperature are you seeing? The only reason for a higher capacity radiator is if it can’t keep up with the thermostat. If your thesis rated at 180°, and your engine coolant temperature starts approaching 200°, then your radiator is getting overwhelmed. But if your coolant temperature tracks within 5° of your thermostat rating, your radiator is working just fine.

That being said, what is your thermostat temperature rating? When was the last time you flushed your cooling system? Have you tried a lower temp thermostat?

 

...and try using some REDLINE WatterWetter. Proven to lower temp.

 

You are trying to fix a problem than doesn't exist. Modern engines and MINI engines are no different run hot at least under some conditions.

As long as there is no real overheating no warning light and the coolant level remains constant -- thus no leak -- and you don't smell anti-freeze when the engine is hot -- another leak sign -- the cooling system is operating correctly.

My advice is to every 4 years replace the coolant. My tech buddies advised me to do this way back in the early 1970s. Fresh coolant helps prolong water pump seal life and hose life.

 

I want to say that mine hits halfway at ~170° and stays there until at least 210° - probably higher.

 

I use a phone app and a OBD II Bluetooth dongle to track my car's performance. It provides an exact digital temp reading directly from the ECU . During the summer my water temps consistently run around 195 F (reduced slightly at highway speeds). Now I realize that is not too high in the Mini world, however, a radiator with better cooling capacity can only help, not hinder, the car's performance. My intent is to lower the temps. Thanks megaDan and NC TRACKRAT for the guidance.

 

A word of caution: While others have had excellent results with Mishimoto radiators, I and others have not. I had two (2) failures. They were under warranty and Mishimoto replaced them but what an aggrevation! Unless your radiator is leaking, I recommend you not replace it until it fails.

 

I also had or considered this question as the OP.
I'm running the original 19y/o radiator in my R53.
Gauge always reads half way after warmed.
Foxwell indicates water temp @/or between 92° -102°C (197° - 215°F) even while driving & stop/go traffic.

It ain't broke.
Won't be tacking. What more do I need ($$$) ?

 

I will repeat my comments above about thermostat performance. If you engine is running at about 195° then I would assume your thermostat is rated at 195°. Before swapping in a new radiator, fine a 185° thermostat and swap that in, with a corresponding coolant flush. If your car then runs at about 185° consistently, then getting a higher performance radiator isn’t going to magically give you cooler engine temperatures. Remember, that the thermostats main purpose in life is to regulate your engine coolant temperature, not the radiator. The radiators function is to only get rid of excess heat from the coolant. If the radiators gets rid of too much heat and delivers coolant that is too cool, then the thermostat will close to restrict coolant flow and bring the temperature back up.

 

Next time I go in, I'm replacing the thermostat housing with an aluminum one, and popping in a lower temp thermostat as well. That should keep your temps down somewhat I would think. I wanted to do that when I lived in SoCal, but never managed to get it done. The MINI really does not like stop and go traffic on the freeways!