Cooling System Refresh - missing anything?
 

I have decided to perform a cooling system refresh on my 2007 4.8i (77k miles), including a preventive fix to the leak-prone coolant pipe. Below is my parts list; am I missing anything?

- Water pump
- Thermostat
- Primary and A/C drive belts
- Coolant (2 gallons unmixed)
- Hoses & expansion tank (replaced at 64k miles, omitting from refresh)
- BimmerFix coolant pipe stent kit (thoughts?)
- Idler pulleys (I am going to measure all 3 idler pulleys and attempt to replace with better metal Gates/Napa/Dayco units. Both tensioner pulleys are only sold as a single unit with the tensioner. If I'm unsuccessful, I will replace with new tensioner units.)

Water pump pulley? Any other seals to replace at the time? The vehicle has already had the timing cover gaskets replaced, along with air pump seals. Thanks all.

Well, I think this covers it (except for the idler/tensioner pulleys). Under $500 for everything. Not bad.

• Primary Drive Belt - ContiTech 7PK1666
• AC Drive Belt - ConTitech 4PK870
• Water Pump - HEPU P414
• Water Pump Pulley - BMW 11517545295
• Thermostat - Mahle Behr 11537586885
• Coolant - BMW 82141467704 (2 gallons)
• Water Pipe O-Ring - Victor Reinz 11517507717 (update: not necessary, included with new water pump)
• Coolant Return Pipe - BMW 11511439976
• BimmerFix Coolant Pipe Stent Kit

Hi, is the Hepu WaterPump Oem? Also, where r u ordering these parts from? Thanks, Sam

HEPU is better than OEM. I did a lot of reading about them. Plus, they have a metal impeller instead of the cheap OEM plastic.

Parts were purchased from FCP Euro and AutohasAZ, depending on who had the better price on each part. Both have free shipping.

I used Saleri water pump which I think is OEM. It also comes with metal impeller. I used HEPU in the past in my e46, and it definitely is a good product. Would recommend it over OE.

Any updates?? Also, how many water pipe o-ring do I need? Thanks, Sam

Haven't had a chance to do it yet. Been busy moving houses and doing an engine swap in my "fun-haver" car.

Well I just completed this. It took about 3 hours to get to the point where I had to wait 24 hours for the RTV to cure. I decided to change the spark plugs and replace the P/S fluid while I was in there and waiting for the RTV to cure. Oh, and I also replaced the PCV breather diaphragms on both sides (Bosch units). Re-assembly of everything took about 2 hours the next morning.

Note 1: I had to jack the front of the vehicle up to ensure the coolant stayed at the back of the coolant pipe, so as to not interfere with the RTV.

Note 2: The "water pipe o-ring" was not necessary, as my new water pump came with one.


Note on spark plugs: Plugs are pretty simple, except for that damn rear driver-side coil. Make sure you have many different size extensions (I used 3: one 1 inch, and two 3 inch extensions). No need for a wobbly. To get the last coil out, you have to trim the stud sticking out that holds a plastic clip for 2 heater hoses. This can be achieved with pair of dikes. I left enough of the stud remaining so it can still hold the plastic clip. Also, I always use anti-seize on plug threads; it protects against thread-galling and makes for easier removal. Another piece of advice, use some di-electric grease on the coil rubber seals (at the top of the coil) makes for easy assembly and removal, and also seals out moisture.