[GSB]

Originally Posted by e90yyc

GSB
And sorry just to be clear you’re referring to the German-made BMW radiator, yeah?

Interesting differences in the fins. I have no idea whether mine was made by Modine or not. It simply had the BMW logo and numbers stamped into the mold, so the logo was raised proud of the plastic. I paid so much attention when comparing the moldings that I am convinced that the Chinese mold was not reverse-engineered but was the actual BMW-spec mold machined from BMW's own drawings, but without the logo.

In any high-volume industry, whether it be automotive or electronics, several factories or suppliers are commissioned to provide Assurance-of-Supply (AOS) for every single part, and to supply spare parts for as long as necessary. Subtle differences from factory to factory are permitted, as long as they meet spec.

Unfortunately, it's the plastic design and the gasket interfaces between dissimilar materials that is the weak point in any product like this. An engineer's instructions are clear... make it easy to assemble, make it cheap, make it light, and make it last the length of the warranty (3 years for BMW). Anything more is overkill and wasting company time and money. A complex piece like a radiator end-tank is FAR quicker and cheaper to shoot in a plastic mold than to fabricate out of aluminum.

In addition, cracked plastic assures a constant source of revenue for dealerships, so they're happy, while we're forced to tolerate the failures.

[StradaRedlands]

Originally Posted by GSB

Interesting differences in the fins. I have no idea whether mine was made by Modine or not. It simply had the BMW logo and numbers stamped into the mold, so the logo was raised proud of the plastic. I paid so much attention when comparing the moldings that I am convinced that the Chinese mold was not reverse-engineered but was the actual BMW-spec mold machined from BMW's own drawings, but without the logo.

In any high-volume industry, whether it be automotive or electronics, several factories or suppliers are commissioned to provide Assurance-of-Supply (AOS) for every single part, and to supply spare parts for as long as necessary. Subtle differences from factory to factory are permitted, as long as they meet spec.

Unfortunately, it's the plastic design and the gasket interfaces between dissimilar materials that is the weak point in any product like this. An engineer's instructions are clear... make it easy to assemble, make it cheap, make it light, and make it last the length of the warranty (3 years for BMW). Anything more is overkill and wasting company time and money. A complex piece like a radiator end-tank is FAR quicker and cheaper to shoot in a plastic mold than to fabricate out of aluminum.

In addition, cracked plastic assures a constant source of revenue for dealerships, so they're happy, while we're forced to tolerate the failures.

No lies detected...

[GSB]

Okay, two updates...

1. During removal and inspection of the old radiator, I discovered that the plastic end-tanks had not cracked or separated from the core at the seams, as is usually the case. Instead, the coolant must have frozen at some point because the cooling tubes had ballooned from the inside and buckled, causing microscopic cracks in one of the tubes and distortion of the entire radiator body. That is not the fault of the radiator, and ANY brand (or type) of radiator would suffer the same fate with frozen coolant. Make sure to use proper BMW coolant, mixed 50/50 with distilled water. Over-dilution with distilled water can lead to frozen coolant and potential damage throughout the engine.
   
   
2. The all-aluminum replacement radiator is a work of art and seemed so promising, but turned out to be a bust. All four of its mounting points will not engage in the radiator mounting shroud, leaving the radiator about 15mm closer to the engine (over 1/2"). Even if it were possible to fabricate stand-offs to accommodate that gap, the fan would crash into the oil cooler lines mounted to the oil filter housing on the N54 engine and airflow through the A/C core would not be as efficient because of the huge gaps.
   With a bit of grinding, I was able to modify the two lower mounting brackets and one of the upper mounting brackets to engage well enough with the radiator mount, but the fourth, upper mount, is impossible to fix because the end-tank itself hits the radiator mount. The plastic end-tanks have a large indentation to accommodate the radiator mount in that area, whereas the aluminum tank is square at the top and completely ignores the need for clearance. (See photo).

[mainbearing]

Bummer! That is the eBay radiator you mentioned?

Digging up FCP Euro's CSF 7046 (for N54/N55), looks like it is a tight fit, a couple of reviews mentioned of wiggling to get it in, but others said it fit right in. Maybe CSF is still the one to go?

Overcooling seems to be the problem with CSF. Apparently BMW's thermostat design cannot seem to handle it, maybe German winters are warmer than we thought.

https://www.fcpeuro.com/products/bmw...f-7046#reviews

Also, here is FCP's CSF 7046 install video. At 27:00 the forward tabs should engage the slots in the radiator mounting frame. At 27:15 he talked about how the lower feet should sit or else the screws and fan shroud will not align properly. Maybe this will help some.

[GSB]

Originally Posted by mainbearing

Bummer! That is the eBay radiator you mentioned?

Digging up FCP Euro's CSF 7046 (for N54/N55), looks like it is a tight fit, a couple of reviews mentioned of wiggling to get it in, but others said it fit right in. Maybe CSF is still the one to go?

Overcooling seems to be the problem with CSF. Apparently BMW's thermostat design cannot seem to handle it, maybe German winters are warmer than we thought.

https://www.fcpeuro.com/products/bmw...f-7046#reviews

Also, here is FCP's CSF 7046 install video. At 27:10 he talked about how the lower feet should sit or else the screws and fan shroud will not align properly. Maybe this will help some.

Yes, mine is the eBay radiator. I checked out the FCP Euro installation video, and there are fundamental differences with the mounting points on the CSF radiator. There was no way that the eBay radiator would go in because of several reasons...

FIRSTLY, its mounting feet are designed differently, and they're far too wide to fit into the plastic channels of the radiator mount. So I ground down the feet to half their width until they were narrow enough to slip into the mount and they finally located properly, but then...

SECONDLY, the top tab (on my left) is incorrectly designed with insufficient clearance for the A/C lines. This is easily verified by comparing the plastic radiator with the eBay radiator. So I ground that tab and got the clearance I needed around those lines. Then the top of the radiator moved closer to where it should be, but then, BAM!...

THIRDLY, the tank itself (on my right) hits the top of the radiator mount. Baffled, I checked the CSF video again and noticed that the CSF has a different design at the top of the tank. The tank itself is angled to clear that mounting area. (See the photo below). The eBay radiator does not have that 45-degree angled tank. It's square. (See the picture in my last post), and it solidly hits the radiator mount with no way around it, except to cut and weld the tank like the CSF radiator. Not gonna happen.

[mainbearing]

Yeah that top corner is the deal breaker. CSF got its complaints but the eBay price is just too good to be true.

[GSB]

Sad but true. BMW has designed the complex shapes on this radiator and its mounting shroud to fit together like a glove. It would be really difficult to design a metal radiator to fit without issues. Even if the design was perfect, the fabrication can fail because aluminum buckles during welding, so the mounting locations can turn out different from one radiator to the next.

Sure, the mounting shroud could be butchered and modified to make this fit, but I'm not prepared to go to those lengths. I'd rather keep it closer to stock.

Note that this same aluminum radiator is available on eBay, Amazon and a few other places, so be careful not to get caught, people! I've ordered the Nissens radiator (made in Slovakia) from FCP Euro instead. Of course, it's plastic, so we'll see how long that lasts, but so far, the reviews are looking good...

[Mike K]

What about these Rock Auto radiator options? Anybody tried any?

They have many choices but here's sampling below:

CSF plastic:

https://www.rockauto.com/en/moreinfo...pt=2172&jsn=12

TYC (some folks had good results with their starters):

https://www.rockauto.com/en/moreinfo...t=2172&jsn=497

Denso:

https://www.rockauto.com/en/moreinfo...t=2172&jsn=498

More results:

https://www.rockauto.com/en/catalog/...,radiator,2172

[mainbearing]

The FCP video above seems to suggest CSF radiator (at least the aluminum one) just fit right in. The problem with CSF all-aluminum seems to be over cooling, as I think BMW's cooling system design is defective -- probably a partial thermostat bypass (such as the "low temperature cooling module" hose on automatic transmissions).

Looking on Rockauto, looks like TYC and Spectrum Premium are popular items there. My guess is there are probably different versions of the plastic radiator frames on the car, so that a radiator fits fine without problems for some owners, but for others you have to trim the "feet" here and there.

Those with N51 and EAC sensor there likely is no choice but the CSF plastic one with the EAC port (not sure if simply tie wrapping the sensor in the fins will work longer term like in one YT video). If tie wrap will work then I would not mind trying the all-aluminum from CSF (and be careful with variants on eBay as GSB mentioned), but radiators with plastic tanks are likely a safer bet for typical driving.

For those who use FCP maybe chat with their tech support too on fitment issues their customers might have encountered.

The consensus seems to be that Mahle radiators SUCK! So I will definitely NOT use Mahle (who bought up Behr).

[Mike K]

I like the RA CSF 3718 plastic radiator's mention that it survives a 10 foot box drop after hearing about broken FCP units arriving busted.

[mainbearing]

CSF 3718 has the EAC sensor port, so it works for both the N51 and N52. They also claim EPDM rubber, so that is good. TYC website offered very little info, but they make all kinds of replacement parts (alternators, starters, lamp assemblies, radiators, condensers, etc).

CSF does seem to have good reviews and the plastic one is $94.79. TYC ($95.79) however carries lifetime warranty for $1 more than CSF, and it is a popular item on Rockauto. I think either one should work fine if you do not need the EAC port.

Whichever one you pick, compare and measure the "feet" and see if they need trimming before you install. See GSB's picture above, the flat tabs next to the "V" index at the bottom of the radiators.

For your 2011 328i, radiators:
https://www.rockauto.com/en/catalog/...,radiator,2172

For N51/N52 there should not be a problem with the back of the upper hose bibb, hopefully:

Originally Posted by Mike K

I like the RA CSF 3718 plastic radiator's mention that it survives a 10 foot box drop after hearing about broken FCP units arriving busted.

[stockbimmer]

be really carefull with your hoses specially the one that connects to the radiator
as they are all plastic the tend to get really hard to take out
when i was replacing mine i accidentally broke the radiator hose and i had to buy a completley new radiator costed me around 180$ canadian and its been running fine for now

[krhodes1]

Originally Posted by GSB

There's a variation on eBay for the automatic transmission for $165, sold by several sellers, like this one...
https://www.ebay.com/itm/156641118297

BUT... WARNING... this one is not compatible with the BMW quick-fit connectors. You have to cut off those plastic connectors, slide the hoses directly onto the radiator fittings, and use hose-clamps the old-school way. Personally, I'd welcome such a change because I've had to replace those plastic BMW quick-fit connectors when they burst too. But wait, I've also had to replace every other plastic part in the cooling system, including expansion tanks, water pumps, bypass hose on top of the radiator, mickey-mouse flange on the engine, and the list goes on and on. Each time they pop, there goes another $35 of BMW coolant... See? I told you the Germans designed it that way!

I really have to wonder what is causing all of this cooling system calamity on a car that really just isn't that known for cooling system issues (compared to the previous generation or two). Ethrrefoh is the high mileage king (and his car is both old and has been wrecked a few times by bambi) and he has had minimal issues. My cars don't have high miles but they are both now +/- 15 years old with zero cooling system problems, and one of them (the higher mileage of the two) has always lived in brutally hot temperatures it's entire life.

I really find it very hard to believe that you got four bad radiators in a row plus all these other bits going pop all on their own.

[StradaRedlands]

The original radiators tend to last a good 15 years, so I wouldn't say an actual failure point. Just something that will happen. More-so the plastic material near the upper hose, but also the plastic/metal interface on the sides.

The hoses tend to last as long as you don't touch them. Then when you remove them the O-ring fails. You don't really need to replace the hose necessarily, just the O rings. But at that age, might as well just do the entire hose. Now the problem is the replacement Rein hoses have seriously dropped in quality, so people are complaining about them.

Just my hot take at least.

[GSB]

Originally Posted by krhodes1

I really have to wonder what is causing all of this cooling system calamity on a car that really just isn't that known for cooling system issues (compared to the previous generation or two). Ethrrefoh is the high mileage king (and his car is both old and has been wrecked a few times by bambi) and he has had minimal issues. My cars don't have high miles but they are both now +/- 15 years old with zero cooling system problems, and one of them (the higher mileage of the two) has always lived in brutally hot temperatures it's entire life.

I really find it very hard to believe that you got four bad radiators in a row plus all these other bits going pop all on their own.

Oh, that's nothing! You should read the rest of my oil and cooling system horrors!

My engine is the N54 turbo, and ALL of the plastic parts crack on that engine. I'm on my 5th water pump, 4th radiator, 3rd thermostat, 2nd coolant reservoir, and I've had to replace every single hose, fitting, and plastic part that comes in contact with oil or coolant, sometimes multiple times. I've even had the pressure relief valve inside the oil filter housing explode, sending shards of plastic and metal into the engine, unfiltered.

The worst culprit of all, is that infamous flimsy rubber Oil Filter Housing Gasket that separates pressurized engine oil from coolant. It seems designed to fail, and when it does, oil leaks undetectably into the coolant, and sometimes, coolant into the oil. The chemical reaction between synthetic oil and BMW coolant causes extreme corrosion to all plastic and rubber parts in the system. But even when that gasket is in perfect condition, the N54 finds a way to blow up, and EVERY time, it spews all of the coolant, leaves me stranded, and leaves me out of hundreds of dollars in spare parts... and of course... another $30 of coolant. I'm beginning to lose count now, but I've had to replace that $30 coolant at least 15 times, following yet another plastic catastrophe! That's over $450 (plus tax) on coolant alone.

If you're ever in the mood for some "entertaining" bedtime reading, here's a post with a small fraction of the issues... https://www.e90post.com/forums/showp...8&postcount=27

[GSB]

Originally Posted by GSB

I've ordered the Nissens radiator (made in Slovakia) from FCP Euro instead. Of course, it's plastic, so we'll see how long that lasts, but so far, the reviews are looking good...

The Nissens radiator from FCP Euro looks well-made, drops right in, and works without any issues. But it IS plastic, so... we shall see... soon enough...

[jackhillstrom]

I have an 07 335i and I replaced mine with a CSF full aluminum radiator. It's worked wonders for me and has been reliable so far for the past 12k~ miles

[GSB]

Originally Posted by jackhillstrom

I have an 07 335i and I replaced mine with a CSF full aluminum radiator. It's worked wonders for me and has been reliable so far for the past 12k~ miles

Good to hear. I hope it stays that way! Personally, I just can't bring myself to spend that kind of money on a car that hates me.

[Efthreeoh]

Originally Posted by krhodes1

I really have to wonder what is causing all of this cooling system calamity on a car that really just isn't that known for cooling system issues (compared to the previous generation or two). Ethrrefoh is the high mileage king (and his car is both old and has been wrecked a few times by bambi) and he has had minimal issues. My cars don't have high miles but they are both now +/- 15 years old with zero cooling system problems, and one of them (the higher mileage of the two) has always lived in brutally hot temperatures it's entire life.

I really find it very hard to believe that you got four bad radiators in a row plus all these other bits going pop all on their own.

Just saw your post. I replaced my original radiator at 350,000 miles after deer strike #4. I only replaced it because the body work required it to be removed for the core support replacement and I was concerned: (a) the radiator got tweaked a bit in the hit, and (b) a ham-fisted tech might weaken the upper bib trying to get the effing upper hose off. The original radiator was fine and leak free, but aged; I drove with the deer damage a few months until it went in for the bodywork.

As far as I know the coolant reservoir is original, which means 18+ years old and 426,000 miles. My first deer encounter was in 2006 with a hit on the right front corner. I'll check the repair paperwork to be sure, but as far as I remember the coolant tank and radiator were not replaced in 2006. The car had only 12,000 miles on it when the body repair was done. Even if in 2006 the radiator and coolant tank were replaced, it's still a shit ton miles and years since 2006.

I did replace all 9 coolant hoses in 2011 or 2012 at 230,000 miles and have not touched them since, except the MM flange at 300,000+ miles. The original t-stat went at 126,000 miles and the waterpump followed at 149,500 miles. I've not replaced either since.

[whyzee125]

Originally Posted by Mike K

What about these Rock Auto radiator options? Anybody tried any?

They have many choices but here's sampling below:

CSF plastic:

https://www.rockauto.com/en/moreinfo...pt=2172&jsn=12

TYC (some folks had good results with their starters):

https://www.rockauto.com/en/moreinfo...t=2172&jsn=497

Denso:

https://www.rockauto.com/en/moreinfo...t=2172&jsn=498

More results:

https://www.rockauto.com/en/catalog/...,radiator,2172

As much as I despise aftermarket parts, I replaced mine recently with the TYCf from RockAuto and so far so good. It's been probably 6 months.

[tlow98]

Originally Posted by whyzee125

As much as I despise aftermarket parts, I replaced mine recently with the TYCf from RockAuto and so far so good. It's been probably 6 months.

Curious why you went with the TYC option? I'm in the middle of this debacle now and I was thinking:
- Shell out for BMW Genuine
- Nissens and risk the plug leaking, but at least people have mentioned what to do

You a sucker for the "heart" on RockAuto, as well?

[Efthreeoh]

Originally Posted by GSB

Interesting differences in the fins. I have no idea whether mine was made by Modine or not. It simply had the BMW logo and numbers stamped into the mold, so the logo was raised proud of the plastic. I paid so much attention when comparing the moldings that I am convinced that the Chinese mold was not reverse-engineered but was the actual BMW-spec mold machined from BMW's own drawings, but without the logo.

In any high-volume industry, whether it be automotive or electronics, several factories or suppliers are commissioned to provide Assurance-of-Supply (AOS) for every single part, and to supply spare parts for as long as necessary. Subtle differences from factory to factory are permitted, as long as they meet spec.

Unfortunately, it's the plastic design and the gasket interfaces between dissimilar materials that is the weak point in any product like this. An engineer's instructions are clear... make it easy to assemble, make it cheap, make it light, and make it last the length of the warranty (3 years for BMW). Anything more is overkill and wasting company time and money. A complex piece like a radiator end-tank is FAR quicker and cheaper to shoot in a plastic mold than to fabricate out of aluminum.

In addition, cracked plastic assures a constant source of revenue for dealerships, so they're happy, while we're forced to tolerate the failures.

Come on man, my original radiator lasted 14 years and 350,000 miles. I replaced it after a deer hit. And it wasn't even leaking. You are convolving poor manufacturing with poor engineering design. Radiators have been plastic with metal core for the better part of 45 years. It's industry standard.