Expansion Tank vs Whole Cooling System

[JohnnyGraphic]

Hi All-

It's been a long time since I've been active on this forum. I'm turning to you all for your collective wisdom.

Here's my problem. My expansion tank just cracked at 138k miles. I've already replaced the whole cooling system (hoses, tank, thermostat, water pump, pulleys, belts and sensors) at 70k miles.

Do I just replace the expansion tank or do I go all-in and replace the whole system again?

If I replace the whole system, should I replace the water pump as well? (It's a Graf pump with the metal impeller). What about the radiator?

Trying to keep cost down, but I'd hate to replace one thing, only to have the other items fail on me. But, if they don't need to be, why spend the money? Those are the questions going thru my mind at the moment.

Let me know how the Mafia votes!

Thanks all and appreciate any helpful suggestions.

[Vas]

60k-70k intervals sounds about normal for the cooling system.

I would do the system again. And not worry till 200k.

[JohnnyGraphic]

60k-70k intervals sounds about normal for the cooling system.

I would do the system again. And not worry till 200k.

That was my initial thoughts, but I was talking with another guy and he is in the other camp of 'don't spend money or replace stuff you don't need to'. That idea appeals to my pocket book! LOL!

What do you think about the water pump and/or radiator?

[Vas]

Radiator I would replace when it starts to leak. Usually the end tanks Crack first.

With the water pump, the impeller might be fine but never know the condition of the bearings inside.
Cooling system is something not to mess around with.

[danewilson77]

68k? Dhu eet all.

Sent from my SM-G925V using Tapatalk

[JohnnyGraphic]

Seems like the overwhelming majority is to go whole-hog and replace it all. Dang, I knew this was going to be an expensive endeavor.

[fredo]

True story on my first e46: Around 145,000 miles my Indy recommended lots of work on the coolant system. I agreed to his recommendations. 4,000 miles later the water pump busted. Not sure why he didn't replace it in the first place. Thankfully no engine damage.

As a side note, this WP issue happened to the new owner on his first day of ownership. Yeah, I sold the car before the mess.

[ELCID86]

I'd do it all but would consider skipping the rad.


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"ZHP is a garbage option anyway- just some cosmetic upgrades with a different cam and diff to claw back some of the performance lost fitting those hideous and heavy wheels. Any 330 with a 3.46 diff will smoke a ZHP every time. The whole Mafia thing reeks of childish behavior." - an e46f member

[JohnnyGraphic]

With everything else off the front of the engine, I might as well replace the water pump. A lot of good solid advice here. Nice to see things haven't changed over the years. A lot of the same ole faces from back in the day. NICE!

You're all reinforcing what I was thinking. The added cost of adding a WP isn't bad at all. Especially if considering having it changed out at a later time.

Now, I gotta go shopping... Any advice on specific parts to get? As in BMW vs X Brand of this part and X Brand of this part and not a BMW part. I've seen both sides of the argument on the BMW composite impeller vs a Graf unit (for example).

[JohnnyGraphic]

I'd do it all but would consider skipping the rad.


---
"ZHP is a garbage option anyway- just some cosmetic upgrades with a different cam and diff to claw back some of the performance lost fitting those hideous and heavy wheels. Any 330 with a 3.46 diff will smoke a ZHP every time. The whole Mafia thing reeks of childish behavior." - an e46f member

Thanks Elcid! The radiator is a pretty hefty investment. If cost were no object, I would LOVE to replace the radiator with an all metal/aluminum unit and same with the expansion tank. Not even sure if they make such a beast. I love this car and would love to keep it running for a long time.

I need to drive it more too. I only put about 7k miles this past year. I've moved a lot closer to my office now. Which reminds me, I need to update my location.

Johnny