Build and advice for Heidi

[fw_fw]

I am sure you know what you are doing - but when the expansion tank blows up spontaneously, you will have seconds to react and might end up with a warped head in the worst case.

You mention in your first post that you want to keep the car safe and reliable - the cooling system scores last in the reliability checklist on the E46 platform. Forget brakes, forget suspension - you should really address the cooling system before anything if reliability is important to you.

+1.....without a doubt, refresh the cooling system, 140K on the original system is a time bomb waiting to go!!

[Her name is Heidi]

First of all, this is a great forum with great information and I really appreciate everything thus far.

Is the expansion tank the main issue with the cooling system? Again, I have no issues at all with cooling at this time but have learned over the years that the cooling system is known to fail often with our cars. Therefore, that is the first thing I check when driving the car. I do not drive it very much anymore. I'll look at replacing the expansion tank and brakes over the next few weeks. The brakes HAVE to be changed at this point.

[BMWCurves]

Definitely attend to your brakes if they're in need, but I'm in agreement with the other members: get to the cooling system sooner rather than later. Hoses burst, expansion tanks can break, thermostats can fail. If one item goes, the other components are not far behind. I've never experienced this issue in a 3 series, but I've seen the plastic inlet on the radiator burst twice on my father's 540i like clockwork every six years, leaving him stranded both times. Not something I'd want to have happen to my car.

You can go with a kit like Vas suggested from Turner. It's what's in my car. However, if I were to do it again, I would order individual parts through ECS Tuning and FCP Euro. Cheaper, and you have more control over the manufacturer of your parts. Parts are listed below:

Radiator (Behr) - 17119071518
Expansion tank (OEM) - 17117573781
Expansion tank cap (BMW) - E46 - 17117639022 (2.0 bar) or E30 - 17137639023 (1.4 bar)
Expansion tank mounting clamp (BMW) - 17111707777
Water pump (BMW) - 11517509985
Thermostat (Mahle) - 11537509227
Upper radiator hose (Rein/BMW) - 17127510952
Lower radiator hose (Rein/BMW) - 11531436408
Coolant temperature sensor/auxiliary fan switch (BMW) - 13621433077
Coolant level sensor (BMW) - 17137553919
Coolant (BMW, 1 gallon) - 82141467704

[anandoc]

Therefore, that is the first thing I check when driving the car.

It is almost impossible to check/monitor the cooling system parts for failure. The expansion tank may develop hairline cracks and go kaboom. The hoses would be very brittle by now and can burst. The belts would also be in a rough shape. The pulleys/tensioners would also be done by now.

Speaking of prone-to-fail parts, have you replaced the fuel pump? Those often fail by this time/mileage. There is a huge thread on E46F on this:

http://forum.e46fanatics.com/showthread.php?t=929501

[Her name is Heidi]

All belts are new and the pulleys/tensioners have also been replaced. Fuel pump is also newer. Oil filter housing gasket has been replaced. And the maintenance list goes on. Checking the system is easy from my point of view you physically get you hands on the hoses IOT check for signs of failure and check the expansion tank for any signs of cracks/leaks. You will also notice any coolant pooling under the car if there is slow leak in the system.

All i'm saying is I understand the cooling system is known to fail with our cars and the system is on the list to be replace as preventative maintenance. Brakes just need to be replaced first and honestly I will mostly likely address cooling system and brakes at the same time. The car isn't seeing that many miles anymore, so knocking out multiple things are one time is what I'm trying to achieve.

I will ask is there any major benefit in going with a Stewart Performance Water Pump over an OEM pump?

[Her name is Heidi]

BMWCurves that is a great and very helpful parts list for the cooling system.

I will ask this question here again - is there any major benefit to going with a Stewart Performance Water Pump over an OEM one?

[holyc0w]

Possibly higher quality and service life with the Stewart pump, but the OEM pump is supposed to be good.

[BMWCurves]

BMWCurves that is a great and very helpful parts list for the cooling system.

I will ask this question here again - is there any major benefit to going with a Stewart Performance Water Pump over an OEM one?

Some people think so. Others argue against it. At a minimum, there's a general agreement that BMW fixed the water pump's composite material so it doesn't disintegrate like old ones used to. And as far as I recall, it takes about 3 replacements to get back the price of the stewart pump, so I have no issue changing the water pump every 60-80k at the current price.

[Her name is Heidi]

Some people think so. Others argue against it. At a minimum, there's a general agreement that BMW fixed the water pump's composite material so it doesn't disintegrate like old ones used to. And as far as I recall, it takes about 3 replacements to get back the price of the stewart pump, so I have no issue changing the water pump every 60-80k at the current price.

Good point


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[Sockethead]

Definitely get the front strut and rear shock reinforcements. Both of mine failed.
here's a couple of threads that I made on my experience that may help:
http://www.zhpmafia.com/forums/showt...77-RSM-fail-X2

http://www.zhpmafia.com/forums/showt...tes-are-a-must

I replaced the coolant expansion tank. at around 80k I'm at 142k. That and the water pump are the only parts I replaced as preventative maintenance.
Other parts I have replaced upon failure were the Thermostat and the water pump. No need to PM the thermostat as when it fails, it fails open and it's pretty gradual.
I've replaced the water pump twice. the first time I replaced it out of paranoia. I replaced it with a Bosch metal impeller, mostly because of what I read online. It failed after 40k...bearing went bad and was making a racket. The second pump was OEM and that was a long time ago. I'm not replacing that until it fails. My car is supercharged and I ran underdrive pulleys for years. I've never had a cooling issue that made me think I needed the Stewart pump. I'm a big proponent of the composite impeller as I worked with pumps for over 15 years... the metal impellers wore out (erosion of the metal due to flow and chemicals) way before the composites. I should of pulled from my own experience the first time I replaced it

I pretty much agree with everyone else that, unless you're a hard core racer, A big brake kit isn't really needed.