How reliable are OEM radiators with plastic end tanks? Has yours failed?
 

Radiators with plastic end tanks have a reputation for cracking and leaking. Often this happens around 100,000 miles or less. Not a lot of twins have this many miles on them, so maybe that's why I haven't heard of this problem yet with twins. Has anyone experienced leaking plastic end tanks? If so, how is your car used and how many miles are on it?
I'm wondering if it makes sense to replace my OEM rad before it fails and use it as an excuse to buy the Jackson Racing unit that doubles as an oil cooler.
Thanks!

The real question is why do you need reliability as an excuse? Go for it!

I've had multiple cars with 2-300k miles on the original plastic radiators. I would trust oem over aftermarket imo

Age as well as mileage plays a role in how long the plastic end tanks last. I'm curious to see how they hold up too though. I intend to have this car quite a while.

no different than OEM hoses vs "high performance" hoses... they are only as reliable as how well you maintain the car.

the vast majority of coolant system failure comes from stuck thermostat or radiator caps, which overpressurize the system and contribute to premature cracking of hoses or plastic.

100,000+ miles and have never lost a drop of coolant (beyond the expected).


and...


What Spuds said.

Thread crossover:
http://www.ft86club.com/forums/showp...ostcount=46822

147k miles here and radiator is fine. I do have coolant evaporation when driven hard but it's done that since I first got it essentially

Got a leak on my 04 WRX at about 120k. Put another radiator on with plastic ends. Cooling is likely not an issue for the BRZ unless you go FI or tracking.

Yeah, the GD radiators go out between 100-120k miles like clockwork it seemed. My old STi broke at 107k lol

But even tracking the oem rad is very efficient (for NA and even some FI set-ups)

I think it is more than just mileage and age. Environment, # of heating cycles, how long it stays hot each cycle, etc., could be factors. I've only had my FRS for 3yrs and 78k miles so my radiator looks fine.
I also have a 99 Miata on which I had to replace the radiator due to cracked end tank.
Assuming all plastic end tanks are made of the same stuff, you don't HAVE to randomly, preemptively buy a new radiator. The tank on my Miata started to turn green before it cracked. This is a known issue/symptom with Miata OEM radiators. And, it's not like it just exploded, spewing coolant everywhere. I just noticed dried coolant around the filler neck (where it cracked) one day and upon closer inspection, saw the crack.

Mine started leaking on my 2003 Lancer at 180k miles. I knew it was dripping because it was dripping. I replaced it for a new unit for like $43 bucks, and it took 30 minutes to install.

That must have been tough spending twice the blue book value of the car.

Sorry, can't help myself tonight.

Actually it was three times the value, but at the time a running car is a running car.

So so true! Awesome.

I think this is more to do with the year and era of when these plastic end tanks were made, these modern cars have better manufacturing processes and quality control on those plastic parts than the plastic parts of old.

I know e36s m3s and other bmws from the 90s-00s had major issues with the plastic end-tanks cracking. On our cars however it isn't an issue.

I have that "issue" but it's more prevalent during the summer, and I've had a gallon of subaru oem coolant in my garage since 2016 that I used to top off the system and it's not even close to empty. It doesn't really lose alot of fluid, almost a 1/4-1/2 an inch of fluid in our 5 month hot summer period.

Apparently someone said the fix is that there's evaporation occurring through the OEM hoses and through the top cap of the expansion tank. So putting tape over the expansion tank cap and swapping the hoses to aftermarket with hose clamps seems to do better. But it's honestly a non issue for me as it isn't a crazy loss.

By the time I did my coolant change I had used almost a whole gallon of coolant to refill the overflow. I think this time around I'm just going to use water to top it off.

BMWs have been running 2.0bar/29psi cooking systems since the 90’s with plastic radiator end caps, and they rarely, if ever, failed. The pressurized coolant reservoirs aka expansion tanks (with much greater effective diameter and hoop stresses) were a whole different story.