I know Mishimoto doesn't make an aluminum rad for the E39, but...

**Justin517** · 06-15-2012, 05:39 PM

is it just me or does the E46 one look just like the E39 one but up-side-down?

E39:

E46:

I'm going to try to figure out what the overall dimension differences are and if the hose connection diameters are the same or not... if so with some fairly cheap modification (add mounts) we may have a $319 all aluminum replacement radiator...

OK, so...

The Mishimoto E46 rad core is 22.8x15.67x2.05 which is 732.4 total area

The OEM E39 core is a bit bigger in surface area at 25.6x17 but is only 1.34" thick for a total area of 583

I havent found out about the hose connections yet though...

**AHay5** · 06-15-2012, 06:24 PM

I'm in to hear from your research. I believe the E46 cooling systems have clip on hose attachments. I wonder if the Mishimoto radiator will work for the clamp on hoses? Also Mishimoto has their own set of hoses.

**Justin517** · 06-15-2012, 06:30 PM

I have a 2003 so I also have the O-ring/clip style hoses... thats the main reason I am looking at mishimoto... for you guys with the hose clamp style I would imagine you can more easily find an all aluminum replacement radiator... its the machined hose connections that make it tough to match up with something form another application or that is "universal".

It looks like both cars are listed as having 1.5" inlet and outlet so we may have a winner... I can't imagine BMW made 2 cars at the same time with the same I.D. inlet and outlet, and same style connector, but with a different locking mechanisim/connector shape...

OK... wait a second... the pictures on mishimotos site shows the radiator with the same orientation as the E39...

yup, it is the same orientation...

That means the drain wouldnt hve to be moved and the mounts may be a closer match?

I think I might see if I can get my hands on a junk M3 radiator to take some measurements...

**dantheman67** · 06-16-2012, 01:35 AM

Subscribed, interested to see how this turns out

**antsE39** · 06-16-2012, 01:39 AM

^ for sure:d

**Jason5driver** · 06-16-2012, 10:46 PM

Ok, but doesn't the Mishimoto's fail as well?

**Rallim** · 06-17-2012, 03:13 AM

Originally Posted by Jason5driver

Ok, but doesn't the Mishimoto's fail as well?

I've heard subpar things about them on Mustangs at the very least.... They're popular but I havn't heard too many super things on them to be perfectly honest.

**1NAWTY5** · 06-17-2012, 08:56 AM

Isnt that what JackEatsEmoKids do for his turbo project?

This radiator is meant for an E46, but now fits the E39 perfectly lol

**Justin517** · 06-17-2012, 08:57 AM

Hmm, I will have to dip some research before proceeding... That may be why they don't make one for the e39.... High pressures and they know they get failures at lower pressures?

Might not be worth it... You can get almost 3 regular radiators for the Mishimoto price...

**97heath528i** · 06-17-2012, 09:00 AM

Ok here is the thing then, if you want to proceed with the Mishimoto then you will need to use Evans which produces little to no pressure.

**ZeroR2** · 06-17-2012, 09:50 AM

Why would they fail? I don't see any plastic, unless the joints are weak. Anyone know?

**97heath528i** · 06-17-2012, 09:57 AM

I am just saying use Evans coolant and there will be no pressure. End of story.

**Schitzo** · 06-17-2012, 10:12 AM

Even aluminum radiators fail especially if mounted improperly and or have improper welds.

I to felt the stock radiators were poorly made hence the reason I don't run one in my 528i but I have since changed my opinion. I believe the biggest contributor to failed E39 radiators, is the pressure at which BMW chooses to run their cooling system. 2 bar (~30 psi) coupled with high temps, significantly decreases the life of the plastic parts in the cooling system.

This is why both my E39s now run the 1.4 bar cap.

**16valex** · 06-17-2012, 10:35 AM

This is why both my E39s now run the 1.4 bar cap.

Hey Schitzo buddy, have a part number for the E30 1.4 bar cap? I don't have any issue right now but figure if it works for you it will for me.

**Jesus Freak** · 06-17-2012, 10:49 AM

http://www.bimmerzone.com/product/VSL-AR-E39M5.html

1.4 bar cap
Part# : 17 11 1 742 232

**16valex** · 06-17-2012, 11:22 AM

Originally Posted by Jesus Freak

http://www.bimmerzone.com/product/VSL-AR-E39M5.html

1.4 bar cap
Part# : 17 11 1 742 232

Thank you!
Cheers!

**E36 328is** · 06-17-2012, 11:41 AM

Doesn't running a lower pressure cap make the boiling point lower in your cooling system?

**Schitzo** · 06-17-2012, 11:48 AM

Originally Posted by 16valex

Hey Schitzo buddy, have a part number for the E30 1.4 bar cap? I don't have any issue right now but figure if it works for you it will for me.

Hi Alex, as JF indicated, the part number is 17111742232. I buy the Behr brand from Autohausaz.

Gary at germanautosolutions is working on a 1 bar cap but I think that is a little on the low side. Then again 1bar (~ 15psi) is the standard pressure cap rating on most cars. Furthermore, 15 psi is the pressure at which most coolant mixes are tested at.
http://germanautosolutions.com/BMW_Solutions.html

Originally Posted by E36 328is

Doesn't running a lower pressure cap make the boiling point lower in your cooling system?

Yes it lowers the boiling point but not enough to cause ill effects. At 1 bar (15 psi), a 50/50 mix of water and ethylene glycol has a boiling point of 264 F. It is obviously higher at 1.4 bar and higher still at 2 bar. There is no reason your engine should be getting to 264F if your radiator and fan are working properly. What this means is, something in the cooling system would have to have failed (e.g. faulty fan, low coolant, faulty WP etc) for the coolant to reach it's boiling point at 1.4 bar.

Justin, sorry for the hijack.I'll stop now.

**Jason5driver** · 06-17-2012, 12:41 PM

Originally Posted by Schitzo

Even aluminum radiators fail especially if mounted improperly and or have improper welds.

I to felt the stock radiators were poorly made hence the reason I don't run one in my 528i but I have since changed my opinion. I believe the biggest contributor to failed E39 radiators, is the pressure at which BMW chooses to run their cooling system. 2 bar (~30 psi) coupled with high temps, significantly decreases the life of the plastic parts in the cooling system.

This is why both my E39s now run the 1.4 bar cap.

My thoughts were also along this line as well.
If the E39 runs at a lower pressure = less things to fail, less wear on the plastics.
And, if the V8's were running Evans on the aluminum radiators, why wouldn't be just as affective/ affordable with the OEM radiator...?

Are you able to run the 1.4 bar cap on the E39 OEM expansion tank as well?
I thought it was only for the E30 expansion tank...

Great information, as usual, Sir!
Thank you!

Originally Posted by 16valex

Hey Schitzo buddy, have a part number for the E30 1.4 bar cap?
I don't have any issues right now, but I figured if it works for you it will for me.

Originally Posted by Jesus Freak

http://www.bimmerzone.com/product/VSL-AR-E39M5.html

1.4 bar cap
Part# : 17 11 1 742 232

Thanks!

**ZeroR2** · 06-17-2012, 02:09 PM

Originally Posted by Schitzo

Even aluminum radiators fail especially if mounted improperly and or have improper welds.

I to felt the stock radiators were poorly made hence the reason I don't run one in my 528i but I have since changed my opinion. I believe the biggest contributor to failed E39 radiators, is the pressure at which BMW chooses to run their cooling system. 2 bar (~30 psi) coupled with high temps, significantly decreases the life of the plastic parts in the cooling system.

This is why both my E39s now run the 1.4 bar cap.

Agreed. What are your thoughts on Evans if you are looking to reduce the pressure, aside from cost?

**Schitzo** · 06-17-2012, 04:16 PM

Originally Posted by jvestal

Agreed. What are your thoughts on Evans if you are looking to reduce the pressure, aside from cost?

I haven't spent much time reading on the Evans coolant and neither do I have personal experience with it. However, I think the "0 pressure" reference is often misunderstood (or maybe I'm the only one confused about it)

The regular ethylene glycol water mix (EGW) coolant, requires pressure to raise its boiling point hence the reason we have pressure caps. On the contrary, Evans coolant does not require any pressure to raise its boiling point. Per their website, its boiling point is 375C at 0 psi.
However, that does not mean if you run Evans coolant and retain your 2 bar cap that you will have zero pressure in your cooling system once your engine is at operating temperature. After all, I believe Evans coolant is still subject to the physics/relationship of volume, pressure and temperature.

So to answer your question, as far as I know, even with the Evans coolant, you would still need a low pressure cap or "no pressure cap" to lower the operating pressure of your system.

I think that is hinted at in the link below from Evans website.
http://www.evanscooling.com/how-it-works/conversion/

**JackEatsEmoKids** · 06-17-2012, 10:41 PM

The E46 M3 radiator is much thicker btw.

You will need to just weld tabs on the top side and use some existing holes on the plastic mounting frame with some screw clips. The two L brackets on the bottom. I will take a pic tomorrow to show you guys how I mounted mine.