Track Car Radiator

**AlpineM345** · 03-20-2017, 10:39 PM

How often do you guys replace stock (Behr) radiators in your track cars? I'm in the middle of installing Z3M oil cooler and need to replace its radiator or swap my daily's radiator over (radiator in my daily's is a Z3M radiator with about 3-4k miles and has tabs for the oil cooler). The current radiator has about 40k miles and 7 years old (it is a regular M3 radiator without provision for the oil cooler). It has been a full time track car only past 6-7k miles. I am thinking that I should just buy a new radiator, but I don't want to throw money away either.

Thanks in advance!

**poweredbyg60** · 03-20-2017, 11:05 PM

this is a track car, then to me replace with aluminum rad no questions. i replaced my non leaking plastic unknown life and other plastic cooling stuff just to know its not going to cut short a weekend event.
throwing away money is what we do, but sometimes its insurance for reliability.

**AlpineM345** · 03-21-2017, 12:17 AM

Originally Posted by poweredbyg60

this is a track car, then to me replace with aluminum rad no questions. i replaced my non leaking plastic unknown life and other plastic cooling stuff just to know its not going to cut short a weekend event.
throwing away money is what we do, but sometimes its insurance for reliability.

I'm not interested in aluminum radiators as cheap ones are junk and nice ones are too expensive. I had Mishimoto one time for my daily, and it started leaking after 2 years. I know that I could spend 1000 for a nice one, but I am not looking to spend 1k for a radiator. I am definitely leaning towards getting a new radiator though instead of swapping...

**timsev** · 03-21-2017, 03:24 AM

Radiators are a wear item. Replace every few years for piece of mind and cheap insurance. Use OEM 3 row from the S54 Z3M (IIRC). I use it in my track car after blowing a crappy aluminum like yourself.

**olemiss540** · 03-21-2017, 07:17 AM

Originally Posted by timsev

Radiators are a wear item. Replace every few years for piece of mind and cheap insurance. Use OEM 3 row from the S54 Z3M (IIRC). I use it in my track car after blowing a crappy aluminum like yourself.

This. A new Behr radiator every 3 or 4 years...

**aeronaut** · 03-21-2017, 07:30 AM

4.5 years, 35k miles, and quite a few track days on my mishimoto. I feel lucky. But I agree with the above, I plan to replace it soon as a preventative maintenance item, and I'll use a Behr 3 row radiator.

**alwaysinboost** · 03-21-2017, 08:29 AM

whatever you replace with, please avoid KOYO. Their radiators are crap and their "lifetime warranty" is BS.

**aeronaut** · 03-21-2017, 01:51 PM

I LITERALLY just made a note to myself last night to buy a new radiator. I walk into garage this morning, and here's what I find:

Luckily, I found a fairly loose hose clamp where the leak was. Hoping that's all it was!!!
Track day this weekend.
Ordering a Z3M replacement today!

**jakermac** · 03-21-2017, 03:56 PM

whatever you replace with, please avoid KOYO. Their radiators are crap and their "lifetime warranty" is BS.

I concur!!

**Haifisch M3** · 03-21-2017, 06:11 PM

no problems with my Koyo..but much cooler track temps than with the previous Mishimoto alum radiator. Probably due to the larger capacity of the Koyo.
In fairness, Mishimoto also makes a large capacity radiator but it was much more expensive than the Koyo

**poweredbyg60** · 03-21-2017, 09:09 PM

Originally Posted by AlpineM345

I'm not interested in aluminum radiators as cheap ones are junk and nice ones are too expensive. I had Mishimoto one time for my daily, and it started leaking after 2 years. I know that I could spend 1000 for a nice one, but I am not looking to spend 1k for a radiator. I am definitely leaning towards getting a new radiator though instead of swapping...

where did yours leak? repairable?
miles?

**AlpineM345** · 03-21-2017, 09:22 PM

Originally Posted by poweredbyg60

where did yours leak? repairable?
miles?

Unfortunately I already tossed the aluminum one. Sorry!

**TXBDan** · 03-21-2017, 09:48 PM

My mishimoto also started leaking. Back to Behr Z3M now.

**hc1001** · 03-21-2017, 10:02 PM

My mishi radiator is fine after 8 years of service. I upgraded to a koyo for the larger capacity and its been fine so far(a little over a year). Ive read about the failures and still gambled. I hope it doesnt crap out, its a really nice piece.

I didnt notice much change in coolant temps. Im NA with a oil cooler and have a lower temp thermostat and spal fan, so maybe thats why.

Alpine, if i were in your shoes, i would just buy a new oem Z3M radiator. Leave the used one in its current car.

**E36forever** · 03-21-2017, 10:23 PM

Originally Posted by AlpineM345

I'm not interested in aluminum radiators as cheap ones are junk and nice ones are too expensive. I had Mishimoto one time for my daily, and it started leaking after 2 years. I know that I could spend 1000 for a nice one, but I am not looking to spend 1k for a radiator. I am definitely leaning towards getting a new radiator though instead of swapping...

But you will spend $2k to get your head gasket replaced. Zionsville makes really nice ones in the $600 range.

**poweredbyg60** · 03-22-2017, 10:27 PM

i was asking about these aluminum leaking, where are they leaking for you guys?
so i can keep a close eye on mine.

**Feffman** · 03-23-2017, 07:39 AM

Originally Posted by AlpineM345

How often do you guys replace stock (Behr) radiators in your track cars? I'm in the middle of installing Z3M oil cooler and need to replace its radiator or swap my daily's radiator over (radiator in my daily's is a Z3M radiator with about 3-4k miles and has tabs for the oil cooler). The current radiator has about 40k miles and 7 years old (it is a regular M3 radiator without provision for the oil cooler). It has been a full time track car only past 6-7k miles. I am thinking that I should just buy a new radiator, but I don't want to throw money away either.

Thanks in advance!

I have a C&R in my M3 from Bimmerworld. It works great.

http://www.bimmerworld.com/Cooling/Radiators/

Feff

**TXBDan** · 03-23-2017, 03:07 PM

Originally Posted by poweredbyg60

i was asking about these aluminum leaking, where are they leaking for you guys?
so i can keep a close eye on mine.

Mine was a dribble where the core meets the end tank.

**jakermac** · 03-23-2017, 03:52 PM

Originally Posted by TXBDan

Mine was a dribble where the core meets the end tank.

Ditto. I have a nice green plume down the end tank where it's been leaking since about 8 months after I got it. I tried the warranty claim avenue. No dice. Several "reasons" why it wasn't covered.

**timsev** · 03-23-2017, 06:14 PM

My Mishi started leaking right in the middle of the rad, right in front of the water pump on the inner side. I don't have a fan so I'm not quite sure how that happened. It was purchased by the previous owner so there was no warranty.

**Crustashio** · 03-24-2017, 06:51 AM

I've had no issues with a stock rad. They're cheap, and they easily last 5-6 years.

**heeltouge** · 03-27-2017, 12:41 AM

Originally Posted by jakermac

whatever you replace with, please avoid KOYO. Their radiators are crap and their "lifetime warranty" is BS.

I concur!!

Curious why you've drawn this conclusion?

I did the Koyo HH, Stewart, aluminum water neck and samco hoses and couldn't be happier? I ran an entire season (ten events) of Time Trials with daily driving duties and the thing never goes over halfway point. I should mention I also removed the mechanical fan and only using the Auxiliary fan. This is southern California track temps on top of that. 105 ambient (max 116 at chuckwalla).

**E36forever** · 03-27-2017, 08:29 AM

^I think it's because of personal experience. If you don't have any issues then the radiator must be good, but if you do have issues then it's crap. It can take some time before enough people start to realize the product isn't very good. Only after years of use and hardly any negative feedback can you say this product is good. In some cases based on the materials used and build process you can predict if something is going to be good or not.

The OE radiator has been in use for long enough with too many reports of failure and in a big way, but the guy above says he hasn't any issues for at least 5-6 years. He's blind to the fact it's a ticking time bomb especially on the track as some people have reported new OE rads failing on the first lap. All radiator warranties are BS regardless even if you will get your $200 back after it fails. In the meantime you're stuck and now you might be in for a $2k head gasket job that isn't covered under that warranty.

Again if MY radiator hasn't failed then it MUST be good. Poor logic IMO.

Oh, and there is the "if you read it on the internet then it must be true" since everyone is speaking the truth. LOL

**Inflame** · 03-27-2017, 08:54 AM

I've ran a KOYO for 3 years now, with the S50 and now LS6. Coolant temps are consistently below 220.

**DocWyte** · 03-27-2017, 03:04 PM

Oem radiators consistently last 70k miles. As long as you rcan place them every 5-6 years you'll be fine.

Shit, the one I pulled out of the M3 I recently bought had a 2004 date stamp on it. Wasn't leaking, that said, I replaced it anyways...