Cooling system overhaul

[ChaseN]

Hey guys. I'm about to do a complete cooling system overhaul on my iX (along with the timing belt) and just wanted to make sure I'm not missing something glaring. A second pair of eyes always helps - I hate the idea of getting halfway through the project and realizing I'm missing shit, especially since its my DD. Let me know if you see anything glaring wrong. I've already got all the drive belts, timing belt & tensioner. Also, if you see any brands that aren't up to snuff, let me know so I can change it in my cart.

Thanks

82-14-1-467-704-M9 100+ in stock
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Genuine BMW Antifreeze, 1 gallon Brand: Genuine BMW
- Core charge may apply in addition to price.
$21.75 $43.50

01-00-1-467-809-M9 96 in stock
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Sticker for Cam Belt Replacement, 325/e/es/i/is/iC/iX (1984-91)
$1.75 $1.75

11-53-1-722-218-M101 34 in stock
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Water Hose, Radiator/Upper, 325/i/is/iC/iX (09/87-91)
$13.75 $13.75

11-53-1-718-980-M101 33 in stock
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Water Hose, Radiator/Lower, 325/i/is/iC/iX (09/87-91)
$6.50 $6.50

11-53-1-287-651-M101 55 in stock
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Water Hose, Water Pump to Thermostat Housing, 325/e/es/i/is/iC/iX (1984-91)
$15.00 $15.00

11-53-1-718-982-M101 37 in stock
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Water Hose, Thermostat to Water Pipe, 325/i/is/iC/iX (09/87-91) Brand: Elaplast
$7.50 $7.50

11-51-9-070-759-M52 100+ in stock
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Water Pump with Gasket (uses metal impeller), 325/e/es/i/is/iC/iX (09/87-92) Brand: Graf
$48.75 $48.75

11-53-1-265-084-M16 100+ in stock
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O Ring, Thermostat 60x3.5mm, 325/e/es/i/is/iC/iX (1984-91) Brand: Bruss
$0.75 $0.75

11-53-1-722-692-M17 100+ in stock
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Gasket, Thermostat Housing, 325/e/es/i/is/iC/iX (1984-91)
$1.75 $1.75

11-53-1-466-174-80-M322 55 in stock
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Thermostat, 80 Degree, 325/e/es/i/is/iC,iX (9/85-91) Brand: Behr Thermotronic
$23.25 $23.25

17-11-1-742-232-M148 84 in stock
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Radiator Cap, 318i/is/iC (1991), 325/i/is/iC/iX (09/87-91) Brand: Reutter
$11.75 $11.75

11-52-1-466-000-M38 14 in stock
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Fan Clutch (Screw on Type), 318i (1984-85), 325/e/es/i/is/iC/iX (1984-91) Brand: Sachs
$71.00 $71.00

17-11-1-468-078-M6 15 in stock
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Radiator, For Cars With Manual Trans, E30 325/e/es (from 9/87), 325i/is/iC/iX (from 9/87) Brand: Behr
$173.75 $173.75

[Dirtbleed]

camshaft seal and o-ring?

[jlevie]

It would be best to also replace the expansion tank, throttle body heater & heater hoses.Then except for the heater core you'll have an all new cooling system.

It would also be a good idea to flush the cooling system before installing the new parts.

1) Get the front of the car 1-2' in the air on jack-stands.

2) Drain the coolant (radiator & block). Set the
heater controls for full hot.

3) Add flush compound and fill with plain water. Then run the engine at normal
temperature as specified by the flush manufacturer (usually about 15
minutes at operating temperature). The engine must run long enough for the radiator to get
hot. In cooler weather it may be necessary to block off some of the air into the radiator.

4) Allow the engine to cool until you can place your hand on the cylinder head
w/o discomfort. Drain the system and refill with plain water.

5) Run the engine for 10-15 minutes or until temp is close to normal.

6) Repeat (4) and (5) until the water drained from the system is clear and
free of debris.

7) Re-install the thermostat and fill with coolant.

Notes:

Always allow the engine to cool to the point that you can hold your hand on
the cylinder head without discomfort. That will prevent scalds from hot
coolant and prevent thermally shocking the head when you dump the coolant.

Filling the system with hot water makes the process go faster and keeps from
having to run the engine a lot in a cold condition (rich mixture).

[ChaseN]

camshaft seal and o-ring?

Good one. Might as well do it "while I'm in there".

It would be best to also replace the expansion tank, throttle body heater & heater hoses.Then except for the heater core you'll have an all new cooling system.

It would also be a good idea to flush the cooling system before installing the new parts.

Thanks for reminding me about the TB heater and heater hoses. I meant to put those in there, good catch. As far as the expansion tank, is it really *needed* on a 100k mile car? Its another $90...if its really a good idea, I'll do it, but wasn't exactly budgeting for it...shit, I'll probably end up doing it anyways. Are they known to fail? What happens, cracking?

[ChaseN]

Ok added everything suggested but the expansion tank. Will probably add that if I can hear a decent explanation for it. Not that I don't believe it may need to be changed, but I'm not in the mood to spend an additional $90 on something that is currently working fine without further encouragement.

Plus the M3 needs a Spal pusher/Zionville Autosport A/C lines, and the automotive slush fund is running below comfortable levels :D Oh yeah, and I corded the front V710's on the 911...and have another event coming up September 18...

[87e30]

Well I can't say I've seen a cracked expansion tank or anything but the new ones sure look damn good.

Someone else may have a better reason.

[ChaseN]

Well I can't say I've seen a cracked expansion tank or anything but the new ones sure look damn good.

Someone else may have a better reason.

Yeah the old ones start looking like shit after a while. I painted it (and the washer fluid bottle) black in my M3 and it looks outstanding. Kind of a pain to check the levels though :D

I only ask about cracking because on 89-94 Jeep Cherokees the expansion tanks are known to crack constantly. It happened to me :( (probably about the only thing that isn't bulletproof on a 4.0l stick Jeep) but I'd never heard of it as a concern on any other car...

[Huff]

If you had a lot of oil and sludge in your old system, you should replace your heater core. A lot of sludge builds up there (it is a mini radiator). I'm doing the same thing right now..