* E46 Cooling Guide (Information w/parts list/bleeding) *

I see no reason why BMW would spec a different radiator for the M56 but I could be wrong. Let us know what you find!

I looked on realoem.com this morning and the radiator for my 6/04 production M56 is part number 17117513922 which is different than the 17119071519 shown in the list. It is also significantly more expensive at $456 from bmaparts.com. The ET, hoses, thermostat and pump are the same. I haven't checked all the other parts.

Any way to determie what the difference is b/w the radiators?

Originally Posted by djacobso

Any way to determie what the difference is b/w the radiators?

Start by calling online vendors to see what they know about their product. Some of them are knowledgeable.

I have a 2002 330 cic manual. Currently I have had no overtheating or coolant leaking issues.

I am going to do preventive mantenance based on age not mileage, but how much do I need to do on a low mileage car? Do I need to replace the radiator? Thermostat? just expansion tank, belt/pulleys, water pump?

Thanks for everyone's advice!! I want to be smart and thorough but not throw money away.

The simple answer is you just can't know for sure.
What do you know about the service history? That would tell us a great deal.
Depends upon your reliable vs. cost tolerance too.
I'd at least recommend the ET and hoses, but not call a full coolant system replacement a mistake. The more you spend, the higher the 'bulletproof' factor.
Test the pulleys (all three) to see if any need replacement. Replace all three at the same time even if only one tests bad. Check condition of the belts.

I've had the car since new. Past maintenance has only been coolant replacement, so everything is 10 years old (with 60k miles). I was planning on Expansion tank and belts at minimum.

I guess my question boils down to:

1. which cooling system components sometimes fail at relatively low mileage?

2. which parts are likely to fail just from age (eg, non-moving parts, plastic, rubber)?

3. are there any components on a prefacelift ci manual should be upgraded due to inherent design flaws?

Yes, def do belts with that age.
Sounds like you've had a very reliable car to date.

1) Two most likely candidates are ET and WP.

2) And at this age, do hoses too.

3) I did metal pulleys for WP and PS too. Some report cracking which can result in way more damage than the replacement effort.

my add coolant light randomly comes on and randomly goes off when I open my cap it says that its at the max amount...sooo next step info?

Sent from my SPH-M820-BST using Bimmer App

First suspect the sending arrangement which is a two part mechanism.
The ET is half the equation with the magnet built into the unit. Then the sending unit attached to the underside of the ET would probably be what you'd want to replace first.
Or possibly a loose connector to the bottom of the sending unit?

I don't know if there's a sending issue because my car doesn't overheat it's properly cycling.

Sent from my SPH-M820-BST using Bimmer App

Level sending unit!

http://www.rmeuropean.com/Part-Numbe..._E095124A.aspx

I feel like it's more of a sensor issue. I just replaced my ETand my radiator and my hoses and I completely flushed the system in it accepted all the coolant so I don't know why that light would still be flashing on.

Sent from my SPH-M820-BST using Bimmer App

so if my car's not overheating and the coolant is properly cycled without any air bubbles technically having a bad sensor would only bring a light up on my dash and not take away from the quality of the cooling system correct

Sent from my SPH-M820-BST using Bimmer App

Correct, it would cause no harm

Originally Posted by djacobso

I'm convinced that its time to replace my cooling system on my 2004 325i that now has 75K miles. However, my car is a SULEV with the M56 engine and I'm wondering if the parts shown in the E46 Cooling Guide are applicable to my vehicle. One of the on-line retailers told me there is SULEV specific radiator and that the standard M54 part will not work. However, I haven't been able to find a definitive answer on that. Are there other parts that may be specific to the M56? How do I go about identifying which (if any) parts are unique? Thank you.

Im replacing my Radiator on my M56, but im doing through SULEV warranty, it has warranty up to 150k miles, or 15 years, But mine is having sensor issues, i get an SES light for an EAC sensor, which is on the radiator. In order to fix this issue the whole radiator has to be replaced. The M56 radiator has a special coating on it that helps with emissions somehow. If nothing is wrong with the radiator dont replace it.

On another note, im doing the whole overhaul, as my expansion tank has crack in it. I used real oem to compare parts, and the only thing i found different was the radiator.

Interesting insight into the SULEV radiator.

And a great reminder that warranty will cover this for a long long time.

Have you had no issues with your fuel pump yet?

Originally Posted by Stinger9

Interesting insight into the SULEV radiator.

And a great reminder that warranty will cover this for a long long time.

Have you had no issues with your fuel pump yet?

Funny thing, yesterday i had some really bad hesitation, i had my RPM jerking under light acceleration, i was too tired last night to scan codes, so i checked them this morning, looks like have a vacuum leak, and i got an error on my fuel pump. Looks like my fuel pump is on the fritz. So im going to put a clain for both part radiator and fuel tank. First thing though is im going to overhaul the cooling system.

Please keep us up to date on this adventure!

I assume you know what the fuel tank/pump costs?

At $500 for the M56 radiator, I think your approach of not replacing it is probably the right choice for me too. Shortly after I posted last weekend I read the sticker under the hood that indicates it is unlawful to replace the radiator with one other than the SULEV part since it is part of the emissions system. That does seem to indicate that an M54 part would work. For now, I think I will do the cooling system replacement without doing the radiator.

I have already experienced the dreaded M56 fuel pump/tank issue and the dealer replaced it along with a myriad of other components under warranty. I'm hoping to get a couple more years out of the car before that issue strikes again.

Originally Posted by ElrichMeister

Funny thing, yesterday i had some really bad hesitation, i had my RPM jerking under light acceleration, i was too tired last night to scan codes, so i checked them this morning, looks like have a vacuum leak, and i got an error on my fuel pump. Looks like my fuel pump is on the fritz. So im going to put a clain for both part radiator and fuel tank. First thing though is im going to overhaul the cooling system.

You indicated above that your going to put a claim in for both the radiator and fuel pump. How do you go about doing that? I was under the impression that you had to take it in to the dealer and then it was essentially up to them to determine what the issue is and whether or not the issue would be covered under the 150k mile/15 year SULEV emission component warranty.