[najnad]

As my X3 is approaching 10 years and 140k miles, I am thinking about replacing the original radiator with plastic sides with an all aluminum radiator. Of course, there are no aftermarket, all aluminum radiators for the F25/F26. However, does anyone know if another BMW uses the same radiator connections as the F25? Then it comes down to measuring to see what else could fit. From a quick image search, the E90 N55 radiator seems to be a potential, but I havent measured and was wondering if anyone else has tried anything like this yet or not.

this is the radiator I am thinking about: https://www.mishimoto.com/bmw-335i-1...tor-06-13.html

The dimensions are:
OVERALL LENGTH (IN) 14.90
OVERALL HEIGHT (IN) 28.30
OVERALL WIDTH (IN) 4.10

Anyone have the dimension for the OEM F25 radiator?

thanks

[Wgosma]

Many moons ago BMW had problems with the necks cracking/failing on some radiators with the plastic construction, but to my knowledge in the past many years that issue has been resolved.

My thought is that if you want to do PM on your car's cooling system, I'd say swapping in a new OEM radiator makes sense - bet you can rely on it to get you another 140K+ miles. Replacing the main radiator hoses makes sense also; if the car's water pump is original a new one at your car's mileage makes some sense too.

[najnad]

The other reason I was looking into other radiators is to see if there is a higher capacity one that can be used on the F25 without too much modification.

[383vett]

Are you having overheating issues?

[najnad]

No overheating, but the cooler it runs the better...for oil life, for turbo life, etc. BMW didn't design these engines for much more than 100k miles, assuming they would be replaced with a new car by then, so repetitive heat cycles beyond that didn't matter to them. So one way to help an engine last longer is to make sure it runs cooler than not.

[Wgosma]

Umpteen years ago when I was driving E39 sedans, some of the guys installed an aftermarket 'High Performance' Stewart water pump (mechanical type) that was both a more robust design (longer service life) compared to OEM plus it was capable of about 20% higher flowrates. unfortunately that's not an option on our cars, I don't think any company is building an electric pump with higher capacity.

Those aftermarket pumps were purchased primarily for their longer lifespan as the key issue was relatively short lifespan of the OEM pumps. the guys who tracked their cars liked the increased flow rate feature.

I have doubts that a higher capacity radiator alone will get you what you're looking for.

https://www.stewartcomponents.com/

[Weslsew]

Originally Posted by najnad

No overheating, but the cooler it runs the better...for oil life, for turbo life, etc. BMW didn't design these engines for much more than 100k miles, assuming they would be replaced with a new car by then, so repetitive heat cycles beyond that didn't matter to them. So one way to help an engine last longer is to make sure it runs cooler than not.

Changing the radiator isn't going to affect engine coolant temp. The computer will just close the thermostat more to keep it at the specified temp. You would need a tune if you want to change coolant operating temp

[383vett]

You’ve driven 140k miles with the stock radiator. It seems like it’s been doing a good job. Changing it would be similar to giving an 80 year old man a new heart when his original heart is doing fine.

[pungo]

Originally Posted by 383vett

You’ve driven 140k miles with the stock radiator. It seems like it’s been doing a good job. Changing it would be similar to giving an 80 year old man a new heart when his original heart is doing fine.

I have to disagree with your analogy. Unfortunately, with plastic parts, they fatigue and become brittle over time with all the heat cycles they go through. Nothing worse then being on a trip and having the radiator crack and start leaking. I'm not sure how long they'll last, but eventually they're likely to fail. I've seen many cracked ones causing the vehicle to get towed to the shop. At 10 years and 140k it has many heat cycles, is it too soon, I don't know, but I've seen many failures after the 10 year mark.

I was doing a preventative cooling system refresh on my E39 at 15 years and 125k miles. When taking the upper hose off, the radiator plastic cracked at the neck, it was really brittle, so was very close to failing.

[Wgosma]

Those older radiators on the E39's and E46 cars were really bad. I think the more current radiators are not as problematic.

[pungo]

Originally Posted by Wgosma

Those older radiators on the E39's and E46 cars were really bad. I think the more current radiators are not as problematic.

Not sure how you came to that conclusion since the F25s don't have the age on them yet with the oldest ones being only 10 years. I know of a busy shop that has changed over a dozen of them in 2020-2021 so unless you have personal experience with the failure rate that you can share, time will tell if the F25 ones are less problematic and last longer than E39/E46

[Wgosma]

The early E39 radiators did not have the o-ring and clamp mechanism we have had for years on newer cars. Used to slide hose over neck and use regular hose clamp on those early models- the necks were not very robust.

[pungo]

Originally Posted by Wgosma

The early E39 radiators did not have the o-ring and clamp mechanism we have had for years on newer cars. Used to slide hose over neck and use regular hose clamp on those early models- the necks were not very robust.

My E39 does not use hose clamps, the plastic just gets brittle after 15 years and was easily cracked. For older ones that may have hose clamps, some idiot probably cranked the clamp so tight, it stressed the plastic. I wouldn't discourage someone from changing their 10 year old radiator, just because you have a hunch it will not fail

My local shop has been changing F25 and similar vintage ones because they are failing, not sure why you can't believe they fail.

Ask EndOfAnEra how his cracked near the hose connection at 9 years?

[383vett]

You’ve driven 140k miles with the stock radiator. It seems like it’s been doing a good job. Changing it would be similar to giving an 80 year old man a new heart when his original heart is doing fine.

Originally Posted by pungo

I have to disagree with your analogy. Unfortunately, with plastic parts, they fatigue and become brittle over time with all the heat cycles they go through. Nothing worse then being on a trip and having the radiator crack and start leaking. I'm not sure how long they'll last, but eventually they're likely to fail. I've seen many cracked ones causing the vehicle to get towed to the shop. At 10 years and 140k it has many heat cycles, is it too soon, I don't know, but I've seen many failures after the 10 year mark.
.
I was doing a preventative cooling system refresh on my E39 at 15 years and 125k miles. When taking the upper hose off, the radiator plastic cracked at the neck, it was really brittle, so was very close to failing.

Let me correct my original statement. Instead of "changing it", insert changing the design. I have already replaced my radiator on my 2012 X3 at 80K

[pungo]

Originally Posted by 383vett

You’ve driven 140k miles with the stock radiator. It seems like it’s been doing a good job. Changing it would be similar to giving an 80 year old man a new heart when his original heart is doing fine.


Let me correct my original statement. Instead of "changing it", insert changing the design. I have already replaced my radiator on my 2012 X3 at 80K

Ok, gotcha, I agree with you that the stock radiator is sufficient to keep the engine running well. I doubt a larger radiator would keep it cooler, unless it's being driven really hard for an extended period of time.

[EndOfAnEra]

Hi, I wish we had more options for our F25s. I did just replace my radiator 2 weeks ago with a Nissens from FCP Euro. I live in Florida, so maybe the warmer climate affected the life of the radiator? Who knows. I am a 2012 with 98k miles.