Zionsville cooling system overhaul on 1999 540it

**BlackBMWs** · 12-17-2008, 05:42 AM

Finished up an install of a Zionsville cooling kit on my 1999 540it as part of an overall cooling system overhaul. This install was made easy by great DIY posts from Blacksapphire, wquiles and Ohmess among other folks. I won't repost pictures that they already did a great job on, but post pictures that were not posted that may help someone else doing the same job as reference. This is my first post with pictures. I have to figure out how to draw on the pictures and have them display, but this'll do for now.

I know many of you may not need the detail in this post, but I know some folks have already asked about the install, so I'll try to answer their questions here.

Here's a great DIY I did print out and used for reference as I did my DIY. I've referenced a couple of Will's great posts to get my jobs done.

http://bimmer.roadfly.com/bmw/forums/e39/8716836-1.html

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I started this cooling system overhaul due to a cracked and imploded Coolant Expansion tank. The 540it has 80k and had it's radiator replaced at least once. Other than the Coolant Expansion Tank, there was no apparent leaks in the system.

The tank had split at it's welded seam, but the vanes inside the cooling tank had also ruptured, so it was damaged more than the exterior showed.

For this overhaul, I decided to replace all cooling components. All hoses (radiator(2), heater(4), alternator to heat exchanger(1), coolant tank to thermostat(1), thermostat to heat exchanger(1), radiator to heat exchanger(1)), cooling (water) pump, Thermostat, Tensioners, Pulleys, o-rings, belts and a Zionsville Cooling kit which consists of the Aluminum radiator, coolant recovery tank and fan shroud, a SPAL fan with dual speed relays and a new coolant level sensor. I also replaced the coolant temperture sensor on the lower radiator hose. All new clamps for Heater and coolant recovery tank hoses. A new cap as well.

I also cleaned as much grime out of the engine and compartment as practical. The engine compartment still needs a good cleaning, but it's way cleaner than before.

I did this overhaul over a weekend and a few late nights. I figure about 20 hours total and about 4 of that overall was just cleaning up the components and engine compartment. Taking my time and getting it totally right was more important than speed for this install. I've not worked on a 540it/M62 before. I'm comfortable with most mechanical and electrical mods and have rebuilt engines on other makes of cars.

Tools/Materials I used:
Metric sockets, 1/4" and 1/2"
Torque Wrench
Torx and allen bits
Hose clamp nut driver
Telescopic Magnetic part pickup tool
Flashlight
Flat and phillips screwdrivers
Dremel tool with grinding and cutting wheels

Voltage meter
Wire cutter, stripper and box cutter
Soldering Iron, Solder
Elecrtical tape, heat shrink wrap tubing, Mini torch
Penetrating Oil, Vaseline, Dialetric grease for o-rings
3/8" Heat resistant wiring sheathing
1/4" diameter aluminum tube for resistor standoff

BMW Coolant/Distilled water
Nylon tie wraps
Ramps & wheel chocks
Bentley E39 manual (Mainly for Torque settings)
Printouts in a binder of key relative DIY posts
Degreaser, Rags, old toothbrushs, water spray bottle
Propane heater (Worked in driveway at night)
Digital Camera

I also had a laptop in case I had any panic questions to send out.

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Part One - Removal, Replacement and Installation

I removed the lower engine compartment cover, air filter box, MAF and big hose to the Intake Manifold. Just as habit, I replace any bolts back to where they belong if they are not in the way of what I need to do. It helps me find and remember what bolt goes where. Otherwise, I use a bunch of ziplock bags and a sharpie marker to keep track of loose parts.

I next removed the Coolant Expansion tank, Radiator hoses, Fan/Fan Clutch, fan shroud, then the Radiator.

Make sure you remove and save the AUC (Air Quality Sensor) mounted on the Fan Shroud. You'll need to mount this on the Zionsville Fan Shroud.

Next, you'll need to remove a metal Emissions Control pipe in front of the water pump. It's held in by two bolts on the ends and a Torx bolt in the middle. There's a plastic Emission Control air hose on the passenger side of this pipe. Mine was fragile enough that it broke in three pieces as I bumped into it when removing the lower radiator hose. The end of the black broken air hose is circled, I'm pointing to one of the end retaining bolts for the air pipe on the passenger side.

After removing the metal Emissions Control air pipe, I loosened the four bolts that holds the water pump pulley since the belt tension would help in the removal. Then remove both belts.

In my case, I replaced both tensioners and pulleys, so I pulled those next.

Remove the wire for the Water Temp sensor on the Water pump, thermostat, then the water pump, being careful not to pull the two metal cooling lines in the top rear of the water pump. I sprayed the two pipes with penetrating oil where they come into the Water Pump. Also sprayed from the thermostat housing opening to one of the metal pipes where I could see it. Six bolts holding the water pump. One lower bolt for the water pump can be removed using a 10mm thin wrench so you don't have to remove the harmonic balancer.

There is one bolt holding a bracket for a hose going to the Tranny Heat Exchanger unit. There are two hoses I replaced here. One the hose mentioned going from the Theromstat to the Tranny Heat Exchanger and one other that goes from the back of the Water Cooled Alternator to the rear top of the Tranny Heat Exchanger.

To get to the connection on the back of the Water Cooled Alternator, it's easier if you loosen the Tranny Heat Exchanger to move it out of the way.

Once the Heat Exchanger is loose, I was able to unclip the quick connector on the hose ends on the Water Cooled Alternator and on the Tranny Heat Exchanger.

Sorry about the shots. Thought I had a better angle. In the above shot, the tranny cooler is on the upper right of the photo. PS pump is directly in the center of the shot. (My PS hose is leaking, another DIY) The point for this shot is there isn't a lot of room to manuver around. (BTW, I had the car on a pair of ramps to gain access to the underside of the car)

Here's the rear connection point on the Tranny cooler. The black plastic connector for the lower end of the hose is visible in the center of the photo. It and many other hoses on the car are the quick clip type which make swaping them out much easier over hose and clamp.

The hose between the Alternator and the Tranny Heat Exchanger was the most difficult hose to change and it was tight, but not so difficult.

I coated the inside of each cooling hose end with Vaseline for easier assembly. After installing that particular hose, I installed new o-rings with dialetric grease in the water pump, installed the Water Pump, Thermostat, new tensioners/pulleys and installed the hose between the Thermostat and Tranny Heat Exchanger. I reattached the water temp sensor on the water pump.

Next was replacing the four hoses for the heater. I used colored electrical tape to mark which hoses went to which connections. I probably could have done it without marking which was which, but it was just more assurance that I didn't cross connect something incorrectly. Use all new hose clamps for the four hoses. The heater hoses for my car do not use the quick clip connectors. Having a flexible hose clamp driver make removing the clamps so much easier than a screwdriver. I had to cut the to hoses that attach to the rear connection on the rear of the engine. (This pic is of the hoses connecting to the heater core, not the rear of the engine block)

I detached the water gizmo (Aux water pump) on the drivers side that three of the hoses attach to. To detach it, I placed my finger under the rubber support on each end of the pump assembly and pressed the plastic shaft or knob upward. It releases the aux pump making replacing the hoses much easier. I believe this pump and other gizmos enables the REST heating feature on my car.

After finishing up the heater hoses, I installed the one hose from under the Theromstat that attaches to the Coolant Expansion Tank. I reinstalled the belts and the metal emissions control pipe. I replaced the o-rings on this pipe before installation.

At this point, I removed the fan and Coolant Expansion Tank from the radiator for easier and light installation. Here's a pre install pic of the Radiator and pieces... I attached the AUC sensor to the Zionsville Fan Shroud at this point. I had to drill two small holes in the support shelf and secured the sensor with tiewraps.

I could not get the radiator in myself, so a buddy and I tried without removing A/C or Power Steering cooling lines. Way tight, no clearance. I ended up removing the Power Steering cooling lines (Catching fluid, about a 1/2 quart of PS fluid drained. ) and slipped the radiator in after removing just a bit of plastic on the drivers side at the Power Steering cooling cooling line bracket. About 3/8" plastic removal with a Dremel. Radiator fit right in after that. I installed the SPAL fan, Coolant Recovery tank, Fan temp switch and Tranny Heat Exchanger hose to the Radiator.

Later, when the system was reassembled, I refilled the power steering pump housing, let the car run for awhile while turning lock to lock, let the system drain again, essencially recircullate and drain the system a total of three times. I then replaced the o-rings at the PS cooler lines to the PS cooler and refilled the Power Steering fluid resivoir.

(sorry, I thought I took a bunch of pictures for these last parts of the installs, but they went into the ether somewhere...)

I installed the upper and lower radiator hoses, installed the new coolant temp sensor, attached the Alternator cooling hose from the upper radiator hose, the Tranny Heat Exchanger hose from the lower right side of the radiator, the hose from under the Thermostat to the Cooling Expansion Tank, the Radiator to Coolant Expansion Tank hose. Attached the wiring for the coolant temp sensor and the Coolant Expansion Tank level sensor.

At this point, I also replaced the plastic emission control air hose I broke early in the process. It attached the air pump to the Emissions sensor on the metal Emission control pipe I removed earlier. The air pump was inside the front fender just above the outside air temp sensor. I had to take off the inside fender liner to reach the pump. Here's a pic with the new hose installed to the air pump. BTW, the wire hanging down in the photo is for the outside temp sensor folks mention sometimes for sensor replacement.

Here's the radiator installed. Ready for Part Two...

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Part Two - Electric Fan Wiring Installation

So, for the wiring, I chose to install the relays in the relay box under the passenger carbon intake air filter. After removing the air intake filter box, an allen head bit is required to remove the four securing bolts for the relay box cover.

I placed both relays in the relay box in the same locations noted by Blacksapphire. I tapped into a 8 GA constant 12V source for the electric fan relay power. (Top right corner in the photo, thicker red wires attached to a terminal on the side of the relay box) I may rerun this constant 12v connection to the battery post by way of the engine wiring flex tunnel at the top right of the relay box. I'm suspect of tapping into this 12V in the relay box as I don't know what it feeds. Anyone know?

I used a Dremel to notch the side of the relay box to run the remaining wires from both relays in a high temp wiring sheath to the engine compartment. The wires I ran were the red power feeds for the electric fan power, the orange switched 12V sense wires, and the two gray wires that run to the Zionsville temperature switch for the two speed function.

I ran the wiring sheath to the interior engine compartment through an access gap I found under the existing wiring conduit. There was a foam plug I removed that was just the right size for the 3/8" wiring sheath.

Next, I ran the two orange wires inside the factory sheath to the diagnostic socket. I tested for a switched 12V source. I read this was a green wire with a white stripe. I soldered both orange wires to the green wire with the white stripe. Once this was done, I rewrapped the wiring harness to retain a factory look.

Next I installed the resistor for the low speed fan power. This resistor gets hot, so I took a lead from BlackSapphire and used a pair of copper/aluminum tubing cut to 1/4" to standoff the resistor from the body. I used a Dremel with a cutting wheel to cut the tube to length. I fastened the resistor and standoffs with two 1" black machine screws.

Resistor shown in the lower center in the picture below. I still have some clean up tie wraps to install.

I attached the two required grounds at the ground connection shown in the lower right of the pic above to the right of the low speed fan power resistor. I next installed the coolant temp switch and attached the gray wires to the appropriate leads. Low speed to T1, High speed to T2. All wires still in the high temp wiring sheath.

(Picture below just showing the Zionsville fan temp switch next to the Coolant Expansion Tank before I wired the gray wires and also before I connected the fan power feed and ground.)

At this point, all was plumbed up and wiring all done. I refilled the radiator via the coolant expansion tank with 1.5 gal of BMW coolant 50/50 mix with distilled water. Temp on heater set to 90 degrees and fan set to lowest setting. I ran the car around the block a couple of times, each time burping the system and adding coolant. I added coolant over the next day a total of 5 times before the coolant level settled down just over the coolant sensor in the coolant tank. In the end, I added just short of three gallons of coolant.

After the cooling system was refilled, I reattached the lower engine compartment cover after confirming no leaks after the system was filled competely.

Here's the finishing touch, a finish nut from Turner Motorsports for the empty water pump fan clutch shaft.

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Observations and Comments:

Since overhauling the system, the OBD reports a steady 108C once it warms up. No leaks, no telltale coolant residue. Next coolant service will be next year when the coolant gets flushed.

What's cool here, is that the Zionsville setup is tested at 4x the normal operating pressure of the OEM setup. That would be 120psi. I suspect I'd burst a hose or connector first, way before the Radiator or Coolant Expansion Tank goes... Also with the electric fan, the exploding fan/fan clutch problem is eliminated and gets rid of parasitic drag caused by the OEM unit.

Thanks again to all of you before me, who did a great job at documenting the overall job. It speeded up my DIY overhaul process and eliminated all the trial and error that usually comes from doing this the first time on an unfamilar car. I hope this helps the next guy doing the job. Let me know if you have any questions...

Cheers!

**Orxan4ik** · 12-17-2008, 05:46 AM

excellent info, thanks man

**FrankMstein** · 12-17-2008, 10:11 AM

I am wondering how one bleeds the air and tell show much coolant is in the tank on these? Can you tell?

**BlackBMWs** · 12-17-2008, 10:27 AM

I spoke to Dwyane at Zionsville to see if the filling procedure was any different than what has been listed a few times in the forums. No apparent difference.

On a level place, fill the system. First fill I used 1.5 gal. Turn car on and set the heater temp to high and turn the fan setting to low. Let car warm up. (I watched the temp like a hawk) Once the needle moved to about 1/4, I turned the car off, open the cap slowly. Air escaped and I was able add another 1/2 gal.

Repeated the process, added another 1/4 gal. Ran around the neighborhood, added another 1/4, gal. probably another 2-3 more times I added probably a total of 1/3-1/2 gal more. I believe I added just short of 3 gal.

The Zionsville does not have a bleed screw like the plastic tanks do. The procedure is slightly different with the bleed screw. I believe you can find a couple of posts on bleeding a stock system.

Hope that helps!

**gjmjan** · 01-26-2009, 01:46 PM

What is your final take? Go for the Full Monty/SDC II? Worth it? I am at 109k with a stockety stock stock 525i-want to keep this guy around-do not want to replace another radiator in 5 years. Your input greatly appreciated.

**BlackBMWs** · 01-26-2009, 01:57 PM

Originally Posted by gjmjan

What is your final take? Go for the Full Monty/SDC II? Worth it? I am at 109k with a stockety stock stock 525i-want to keep this guy around-do not want to replace another radiator in 5 years. Your input greatly appreciated.

Worth it for me I tend to keep cars a long time. I no longer worry about the rad, cooling tank or fan exploding. Next items will be Thermostat or WP in about 50k miles and in those cases, that should be a leak, not an explosion which takes out these engines...

Now I can focus all my concern on the Auto tranny...

BTW, when I did it, I did the full overhaul, to not have to do piecemeal repairs with hoses, tensioners, pulleys...

**TFD528iT** · 01-26-2009, 04:19 PM

so what was the total price tag for this project? I'm looking to replace the cooling system in my 528iT.

**dgz32** · 01-26-2009, 05:11 PM

Good work!

**BlackBMWs** · 01-26-2009, 08:59 PM

Originally Posted by TFD528iT

so what was the total price tag for this project? I'm looking to replace the cooling system in my 528iT.

Should come in at around $2100-2200, depending on how complete you go and who you buy the other parts from. The Zionsville SD kit shipped and taxes ran just under $1500. I bought parts from the BMW dealer with CCA discount, but were still way higher than I could have got the same OEM parts from suppliers on this board.

High cost, but in my case I did every rubber hose, tensioner, WP, Thermostat, sensors, pulleys so I justified the cost by having to do the labor once. I'm counting on that payback over the next 5-8 years. For me, peace of mind was worth the difference...

Nice dogs!

**1NAWTY5** · 01-28-2009, 06:37 PM

Does any one know what the air quality sensor is for?

Great write up. Should be a sticky

**BlackBMWs** · 01-28-2009, 07:10 PM

Originally Posted by 1NAWTY5

Does any one know what the air quality sensor is for?

Great write up. Should be a sticky

Thanks much! I'll ask Gumbi4u if it can be stuck or moved to E39 DIY. Ken?

The AUC? Couldn't find it anywhere but in the Bentley manual. I figured it was the auto sniffer for the auto recirculate function in the 540i's

**boomshakalaka** · 01-28-2009, 07:47 PM

I really wish I took my time when my radiator cracked. The car was fairly new to me, and I was kinda flustered. I needed a car to get to school, and in hindsight the indy I was going to is a pos and wasnt patient at all. I forget exactly what I spent, but I think for maybe 500 more I could have gotten the zionsville metal setup.

No problems so far from the plastic, but still I worry.

**f10_M550i** · 01-29-2009, 11:48 AM

Hey guys I have a question.
I just replaced my fanblades (because I had broken one blade doing an alternator replacement).
The new blades seem to wobble a bit, it turns smoothly and I don't feel any vibration, but I don't recall the original fan blades having any wooble.
Not sure what to think?

**BlackBMWs** · 01-29-2009, 11:52 AM

Replace with an OEM fan. The wobble will damage your WP over a short time. What condition is your fan clutch, may want to consider replacing them both as it may be time...

Small world... I used to live in Centreville...

**jamesdc4** · 01-30-2009, 12:05 AM

Nice job! Thanks for sharing.

**BlackSapphire** · 02-02-2009, 08:17 PM

Awesome write-up. Great job with tons of pics. It'll no doubt help others out there. That's what this forum should be about.

**gcbimmer** · 04-16-2009, 12:58 PM

Great diy. Beyond my capabilities, but nice to know the info is here when my knowledge and confidence grow to tackle something like this. I will also have to have and a 540 by then.
Thanks.

**ozx5** · 04-24-2011, 01:19 AM

I looked all over the Turner site for that finishing nut and "narda" any one help

Originally Posted by BlackBMWs