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Old 07-17-2010, 03:26 PM   #1
Registered User
Join Date: Nov 2009
Location: Jayhawk Central
Posts: 525
My Ride: '01 TiAg 325Ci 5mt
DIY: ECS Tuning level II cooling system refresh + 3 cooling hoses (Step by step)

Steps. 6.5 hour job for a beginner. This write up really is for a dummy. If you can read this post and turn a wrench then you have no problem.

Alright guys, so I just did my cooling system overhaul using the ECS Tuning stage II refresh kit, plus I did the 3 (main I guess) cooling water heater expansion tank hoses, whatever you want to call them. My car has 130k miles on it so I decided now was the time for me to do this, I didn't want to have to post a horror story instead. I decided I should contribute to this forum by posting a step by step DIY as well.

NOTICE: My car is a 2001 325Ci, coupe with the M54b25 engine. So your car MAY be different in some ways, but I'm not aware of many major differences... at all.

Here is exactly what I purchased.

And here is what comes in the stage II kit:
Water pump
Water pump pulley
Fan switch
Thermostat & housing
Sealing gaskets
Expansion tank & cap
1 Gallon Coolant
Upper & lower radiator hoses
Accessory drive belts
Radiator drain plug
Coolant level sensor
Level sensor clip

I'm really pissed because just a week after I bought my kit, ECS decides to create and sell a kit for $6 more including their ALUMINUM water pump pulley instead of the composite plastic one... OH and the GEBR water pump included DOES have a metal impeller, so that's what you want.
EDIT: Upon reading this thread, Joe@ECSTuning decided to send me their aluminum water pump pulley FREE OF CHARGE, in order to rectify the fact that the kit was unavailable when I ordered. Thanks Joe!

I'll explain to you exactly how my experience went. This was my first major-ish project that I've done with my car. Before this the most in depth job I've done was replace my spark plugs. I'm only 20 years old and by no means a mechanic or wrench head, and I tackled this job pretty much by my self in about 6.5 hours including a few breaks. So yes any of you can do it as well if you are even somewhat capable of using tools. It was fun to do and I learned a lot about my car.

Also here is the DIY I followed off of e46 fanatics. It helped me out A LOT, but I did more than this DIY shows. Here is the link if you want to check it out as well.

For this DIY, left = passenger side; right = driver side.

SOO on with the DIY.

1. First of I jacked up my car on the front, both sides, so that I have access all around above and below the car. Put up on stands of course.

2. The approach I took was to remove ALL of what I was replacing and then reinstall ALL the new components afterwards. FYI removal is a total SOB and reinstall is 234234643576773452345 times easier.
So under the car remove the splash guard with a phillips screw driver, like 7 screws which stay attached to the splash guard.

3. Next take a bucket or pan (I used a 5 gallon bucket cuz I had my car high enough) and place them under the radiator and expansion tank drain plugs. They are blue circle plugs with a large phillips head. You can use just about anything that will fit in there to un screw them. Be careful not to damage them as they are plastic. The radiator drain plug you will replace because a new one comes in the kit. The expansion tank drain plug however you will reuse, it also STAYS in the housing, so don't try to remove it. I do have a MANUAL transmission by the way, ECS says that there are different ones of these plugs for manual and auto :dunno

4. After those have drained out move to the engine block drain plug. It is in between the two exhaust manifolds up in a pretty easy to acces area on the passenger side of the engine. It is easy to see and easily recognizable. You will need a 13mm socket a couple (2 or 3) long extensions and a universal (bendy elbow attachement) in order to get to it with your rachet. Unscrew this and take it completely out, with your bucket ready to catch the coolant. Oh umm... FYI don't put the bucket directly under the plug...as the coolant will not drip strait down, No more like put the bucket 18 inches towards the passenger side of the car because the coolant will shoot out like a river! You then will have to move the bucket closer as the river dies down. FYI again, it IS going to splash everywhere off of your steering rack and pinion and other things so guard your eyes and close your mouth! After this all drains out I got back up above the car and blew hard into the expansion tank opening several times to make sure I got all of the old coolant out. Once this is all drained it is time to start removing components.

5. The first thing you will need to take out is your air intake. I forget how to take it out if you have a stock air intake, because I have an after market one. But that link that I posted above will tell you how. It is not hard and you can search how to if you still can't figure it out. Remove what ever you've got in there and disconnect the Mass Air Flow sensor and remove that as well.

REMEMBER to make or distinguish in some way ALL of the parts, bolts, nuts, and clips that you remove, for easy reinstallation with zero problems. Also make note of every sensor plug and whatever else that you unplug or remove so that you remember to put them back during reinstallation. (I actually forgot to even put on my air intake before I fired it up to test it out at the end.....)

6. Remove the air duct thing that is above your kidney grills. It takes 3 pins that you pry up on the center part and then pry up the whole pin clip. If you have ever done any work on your car I'm sure you know how these work by now.. they are stupid. BMW should have used screws instead.. :mad I will also refer to these as "pin clips" from here on.

7. Fan removal. For a manual it is very easy, I guess you need some sort of HUGE special wrench if you have an auto...
To do it on a manual you unplug the two electrical connectors on the passenger side of it, pop out the pin clip on the right side of it, and remove the Torx T-25 screw (I used a T-20 because I didn't have a 25 and it worked). After this simply lift out the fan.

Once you have the fan out you have a lot more room to work in so that you can start removing parts. It doesn't matter which order you remove some of the parts in (unless things obviously have to be removed before you can get to others) but here is the order I did it in.

8. Take off your belts. I have a hydraulic tensioner on my main belt and a mechanical one on my A/C belt. For the hydraulic tensioner you use a Torx T-50 bit, put it on the center bolt of the pulley on the tensioner (after you pop off the dust cap) and turn it CLOCKWISE. Use a breaker bar as it was hard not to for me. This will depress the tensioner, then pull the belt off the pulley. Take out your wrench and pull the belt out.

If you have a mechanical tensioner for this main belt you just use a 5/8" socket and put it on the "nut shaped" part of the tensioner and turn it away from the belt to release tension.

For the A/C belt mine had a mechanical tensioner. Use the 5/8" socket and turn it away from the belt to release the tension. Remove both of the belts.

I then removed all of the hoses at once. NOTICE If the hose attachments are hard to get off, like they are glued on, spray some WD-40 around the fitment and let it soak to loosen it up. That should make removal easier. BE CAREFUL not to damage the plastic attachements that the hoses attach to. Also the hoses will still have some coolant left in them that will drain out when you remove them.

9. On the upper radiator hose pull up the easy release clips, two on the expansion tank side and one on the thermostat side. Don't worry about saving the old bleeder plug because the new hose will have a new one too. Pull the hose out.

10. Remove lower radiator hose. Unplug the sensor attachment from the top of it. This goes to the "fan switch" inside the lower radiator hose, don't worry about saving that either because the kit comes with a new one. Pull up the easy release clips on both ends of the hose and pull that hose out.


11. Remove the two hoses attached to the expansion tank.

The upper one goes clear to the back behind the engine to the heater core behind the fire wall. You will need to remove your cabin air filter tray to get to this.

11a. First turn 90 degrees clockwise the three white spring loaded clips. Remove that cover and then your filter.

Take a Torx T-30 (I think that is the correct size, I did not have one so I used a allen head socket which worked) bit and remove the four screw securing the tray. Pull that up and out. For even more hand room you may want to remove the back wall behind that. Remove the two other (one per side) Torx screws on the wall and pull that up and out.

You should be able to see two hoses attach into this back wall. The one with the blue ring around it is the one you are going to remove. Take a flat head screw driver and un screw the clamp, pry this hose off. Pop up the clip on the attachment on the opposite end attached to the expansion tank and pull that off. Pull the hose out.

12. Remove the lower expansion tank hose. This hose is short and attaches to the right side of the engine. Pop up the clips on both ends and pull the hose out. You will most likely need to get back under the car to get it off of the expansion tank because it is on the bottom.

13. The next hose is kind of a pain in the a$$. I sure hope you've got small and nibble hands for this one. The front of it is just an open ended hose with a clamp over it to secure it to the "water inlet valve." Just unscrew this some and pull it off. Use a flash light and follow the hose back with your hand, reaching around. It goes all the way back and around to the back of the engine. You may want to remove the right plastic engine cover (the ones with the white groves) because this gives you a little peep hole to see down to the opposite end of this hose. Once you have found it you can attempt to pop up the pin to remove it. However I could not get any sort of screw driver back in that area so I fed a wire down through the peep area and hooked it around the wire clip and pulled it up. Actually.... that was kind of hard to and I remember now that my dad was able to get some sort of little something back behind and pry up the clip. How ever you can pop it up to remove the hose.

Finally once you have gotten these 5 hoses off you can remove the thermostat and water pump.

14. Start with the thermostat because it is above the water pump. Unplug the sensor attachment clip from the top of the thermostat. Remove the four bolts (3x 10mm and 1x 13mm). Pull off the thermostat, you have to turn the right side downwards because there is a metal arm that kind of holds it on.

15. Remove the water pump pulley. There are 4x 10mm bolts attaching it on. Have someone help you by holding the pulley still, because it will turn when you try to take out the bolts. This shouldn't be hard because the bolts are not torqued on tight at all. Once the four bolts are out, pull off the pulley.

16. Take out water pump. Remove the 4x 10mm bolts. The pump will most likely be stuck on, so screw in two (one on each side) M6 (6mm metric bolts) 25mm in length about, into the two side holes on the pump (They are the two that you didn't take any of the bolts out of before). You want to thread these bolts in until the contact the engine block, once they do, continue screwing them in EVENLY. This will pry the water pump out of the engine block.

17. OK the dreadful Expansion tank.... I removed this last because I tried a few times and said F it and took something else out because it was SO HARD to remove. Unplug the coolant level sensor plug. You can remove that if you want but there is a new one in the kit. Everything should now be disconnected from the tank so, if you are lucky, get above it and grasp it from underneath or however you can and pull it up. This did not work for me so after a while of trying I had my dad go underneath the car and beat up on the bottom of it with a hammer while I pulled up. This got it out.

Now you've got everything removed. This is sort of the mid-way point of the job though you already got basically ALL of the HARD work done and the rest of the job will go 23423562346234 times faster. Take a lunch break if you need to.

18. Flush out the engine. I rolled my car out side and used a water hose to spray through the engine to flush it out good, I sprayed through the thermostat and water pump openings. Remember to flush out the radiator too, unless you are replacing this as well. In which case I do not cover that in this DIY but I'm sure it is just a few more bolts away to pull it out. I could see blue coolant coming out for sure when I did this, so I think it was a good idea to do.

I did flush the whole system out again once I got all the new parts put back in with DISTILLED water, so don't freak out on my anyone saying I shouldn't have used faucet water. I'm convinced that it will be fine and the faucet water can't hurt my engine after this, especially once extremely diluted with my 50/50 antifreeze distilled water mix.

Next install everything back in the REVERSE order that you took them out. Lubricate all fittings and attachments with diluted coolant to make them slip on easier.

19. Putting the new expansion tank back in was almost just as hard as taking the old one out. If you can muscle in the two fittings at the bottom into the tank, you lucky. If not, I removed that whole bracket which the tank attaches to so that I could put it on out side of the car. To remove the bracket was just two Torx T-25 screws, one at the top right and one at the bottom. It pulled out and I used a rubber mallet to beat on the fittings to the new tank while my dad held it. Reinstall the bracket and tank same way as you took it out.

20. Install the water pump. Lubricate the O-ring and slid it in. It was hard to push in all the way so I had my dad push in on it while I tried to thread on the screws. It eventually pushed all the way in. Tighten the nuts back on and torque to 10Nm (about 7 ft/lbs)

21. Install the pulley back on. Have someone hold it for you while you thread and tighten the four bolts back on. Torque them to 10Nm (7ft/lbs). Do not over tighten because the pulley is plastic (unless you get the aluminum one...)

22. Install thermostat. Lubricate the gasket with coolant and place it in. Again turn it a bit to get it around that little arm. Put the four bolts in and tighten them (can't find a torque spec right now but remember how hard they were on) Remember to reattach the plug.

New thermostat and WP

23. Install all the hoses. Very simple way easier than taking them out. Just remember which ones go where and remember to have the wire clip pulled up and then push it down once the fittings are attached all the way. Just reverse the process of how you took them out.

23a. On the lower radiator hose, take the new fan switch. There will be an O-ring in the box with it. Lubricate it up and put it on the fan switch. Put it in the place for it on the new lower radiator hose. Install the hose and re attach the plug to the fan switch.

24. Once you've got all of the new parts installed, I flushed the system out again with distilled water. Pour it into the expansion tank and let it drain out. I blew into the tank opening again several times to try and blow it all out.

25. Don't forget to close back up the drain plugs. I first let the car back down flat and then jacked it back up to try and get any final drops of water out of it. Go back under the car and install the engine drain plug. Torque this to 25Nm if you can get a torque wrench to it. Install the new radiator drain plug. Retighten the expansion tank drain plug. Not super tight at all just until you can't turn them anymore with out forcing them.

26. Once you've got those all attached reinstall all of the other junk; cabin air filter housing, air intake parts including MAF sensor, fan (remember to plug in the two plugs again)

After all of this stuff is put back in you can start the coolant fill and bleed process. :redspot Last leg of the race.

These are the directions that I followed, though there are many argued over procedures on the forums about how to fill and bleed coolant.

1. Mix 50/50 OEM coolant with distilled water (1 Gal + 1 Gal) 2 gallons total
2. Set ignition to ON (engine off) position, set the heater fan to lowest speed and temp setting to max (91 degrees) this will open the heater valve for proper bleeding.
3. Slowly pour mixed coolant inside expansion tank until bubble free fluid emerges from bleed plug.
4. Screw bleed valve in place
5. Start engine and allow it to operate until warm (thermostat opens)
6. Watch for any leaks and also watch the temp gauge. If it goes beyond middle turn engine off and check for air pockets and re-bleed system.

Hope this DIY can help some of you. Have fun working.


Last edited by CokMinusTheS54; 08-12-2010 at 05:48 PM.
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