01-29-2012, 04:39 PM
Location: Macon, GA
Join Date: Feb 2010
Mein Auto: 2003 BMW 525i
Notes from my cooling system overhaul
I Completed my cooling system overhaul this weekend. First off you really need to read the cooling system overhauls by bluebee and cn90 http://www.bimmerfest.com/forums/sho...23&postcount=3(I love their work. I have also attached cn90's diy w/ pictures in pdf.
I am not a mechanic, I know how to change the oil, tires, spark plugs, the basics. It took me running out of cash to attempt serious work on this car. It is not as difficult as it seems once you get the covers off. One thing to note, one month before I started this I paid around $200 with my mechanic, not the stealership, to have the expansion tank removed. I felt like an absolute idiot when I had the fan shroud off and it was right there. That was all the motivation I needed going forward.
I would recommend using ramps rather than jack stands. I got a set of plactic ones from Advance auto parts for about 30 bucks. Too many horror stories on jack stands for me! Very easy to take the cover off the bottom with these.
The problems I encountered were the following:
1. The 32mm wrench to remove the fan is non-negotiable. The 1 1/4 wrench will not work. DO NOT WASTE YOUR TIME!
2. When removing the fan shroud be very careful to pry upward, not forward. When I removed mine I pried it forward and it broke the vent spout on the top right hand side of the radiator. This was an issue because I initially was changing out the water pump and the belts. So I was forced to epoxy it back together until the radiator and hoses arrived. This is a very temporary fix as it could not gain a total seal and the antifreeze degrades the epoxy over time. It lasted two weeks, just long enough to get the radiatior and hoses in.
3. When removing the fan use the 32mm and a hammer. There are numerous tips and tricks with counter pulleys and such, but everybody has a hammer. Use a real hammer(not a small one) or a rubber mallet. 3 hits and its off with wd-40.
4. I used a GBM water pump 59.99 at advance auto parts, water pump came with the o-ring. It did not come with a gasket. I used the gasket maker, no problems with it.
5. Belts were simple. Mine has the mechanical tensioner and the belt diagram is on the diy.
6. I used a CSF radiator 80.00 from auto part warehouse dot com OEM replacement. The radiator was very difficult going in and out. If you have any thoughts about replacing the radiator and not the hoses, FORGET ABOUT IT! The radiator will not come out with the bottom hose attached and once you have it off... THIS IS NOT SOMETHING YOU WANT TO DO TWICE! To get the radiator out you have move the left side forward, then start pulling up, while slightly moving the ac hoses very carefully to the side. I pulled off my rubber stops on the way out which helped alot. Putting it back in was just as hard.
7. The top and bottom hoses were about 40.00 together from auto parts warehouse dot com. Pull the clip up with a pair of needle noses and pull loose. Putting them on I had to grease the radiator and hose coupling to get the new ones on. Same thing with the sensor in the lower radiator hose. I had grease the hole as well as the sensor, wrap with towel (so I would not break it) and squeeze it in. I did this part at the kitchen table. I could not imagine it going in while attached to the radiator.
After that put everything back together. Don't forget the plastic clips at the bottom of the radiator. The new radiator came with some but I used the original ones. Now fill up with antifreeze, start it up, turn the heater on high and top off.
This is the best I have on it. This just what I ran into. Hope it helps somebody!