e90 heater core replacement (diy)
TRANSCRIPT
E90 Heater Core Replacement (DIY)
Required tools:
Interior trim tools (plastic)
Torx set
Reverse Torx sockets
A/C maintenance tools (gauges, R134a, scale, storage tank)
Screw drivers
Metric socket set
Torque Wrench
BMW OBD Software ( I use Bavarian Technic…good software)
Diagonal wire cutters
Zip Ties
NOTES:
Please allow for an entire weekend to get this done (even with a helper). You never know if/when you will run into a snag. It took me approximately 16 hours to get this done and I had a helper. You will also need a/c specific tools to do this yourself. If you do not have the scale, gauges, and proper R134a tanks, find someone that does. The book says not to run the engine when the system is depressurized as it may cause damage. I can not vouch either way on this as I did everything at home.
If you have the BMW shop manual (For BMW mechanics) as I do, the seven numbers preceding the task reference the task number in the manual. If you do not have the manual, disregard these numbers.
Be sure to identify the manufacturer of your core BEFORE purchasing a new one. There are two different manufacturers and they fit differently. The core in these photos is a DENSO.
PROCEDURE
6450009 Draw off the a/c system (R 134a)
(Re service according to the sticker under the hood)
Apply the parking brake
Shift the car into “N” neutral
2516061 Remove grip for shift lever:
Pull straight up DO NOT TWIST. (No hardware to remove). It will be tough, keep pulling!
5116210 Remove trim for preselector (shift) lever:
Pull leather taut. Insert a trim tool under the left side of the trim in the middle to release the first clip. The other clips will likely release along with it if you are pulling hard enough on the leather. Be careful not to pull too hard as there is a wire harness attached underneath. Disconnect harness and remove gaiter assembly with trim.
5116212 Remove trim for storage compartment (wood grain on center console)
Open the storage compartment door. Using a trim tool, start from the back and work your way forward on both sides. (Photo doesn’t show, but the shiftnob gaiter should be removed already)
5116200 Remove storage compartment
First move both front seats all the way forward to remove the rear vent and ash tray assembly. At the seem at the bottom right and left, reach up under and release tabs over catch. Pull the bottom out one inch, then work your way up on both sides disconnecting the spring clips. Disconnect the small electrical plugs now. You will need to disconnect one black plug and one white plug (rotate the top towards the front of the car removing it from the cubby it is in allowing you to unplug the wires). Next, remove two nuts securing the back of the console.
Now, slide the seats all the way back. With a trim tool, pry at the side of the brake handle boot releasing it from the storage tray. Pull it up over the handle. Look inside the hole, you will see a ¾ by 1”
black plug (if you do not have iDrive) and an antenna plug attached to a dummy tray. There is a spring clip underneath the plug on the front; find it, release it, and slide towards the front of the car.
Move to the front of the console, there is a white plug that removes the same way as the black plug you just removed. Remove this one too. On the right and left side of the console near the front, you will see two rubber covers, remove the covers and remove the bolts under them to remove the storage compartment assembly. Manipulate the e-brake boot through the opening and under the console as you lift it out. If you release the e-brake to do this, remember, the vehicle is in neutral!
Put both front seats in the full rear position and lowered completely.
5147171 Remove battery cover / flap in trunk (right side)
6120900 Disconnect the battery
6431081 Remove upper microfilter housing
Remove 6 bolts from cover and remove.
6431092 Remove lower microfilter housing
Disconnect latches and remove covers from right and left side (disconnect wire from right side).
Remove two bolts. Remove two rubber retainers.
Depress detent lugs (clamps) and remove cable harness from the lower housing.
Release three additional clamps and remove second harness. Remove lower housing.
1371000 Remove intake filter housing
Remove front duct by removing two T20 torx screws.
Remove two bolts on right side of filter housing. Disconnect MAF (not pictured but located on top of the air duct dust aft of the filter box).
Loosen clamp on manifold and remove intake in one piece.
3231070 Remove lower section of steering spindle
(E12 torx socket) Adjust steering wheel so the clamping screw is facing up. Remove screw and disconnect.
**CAUTION** After the lower linkage is disconnected, secure the steering wheel so that it does not rotate. There is an airbag spring in the column that will brake if the wheel rotates too far in either direction. If you are off by 180 or 360 degrees degrees on installation, this will allow the wheel to rotate too far in one direction causing the spring to break.
6451520 Remove expansion valve (for the a/c)
WARNING!! Make sure you have depressurized (draw off) the A/C system BEFORE performing this task.
(#6 Allen bit) Remove two 6mm bolts from refrigerant lines and move aside.
(T30 torx) Remove two T30 bolts from valve and remove valve. Remove retainer from refrigerant lines. Cap the a/c lines to prevent moister from entering the system.
Remove both water lines. Remove clamp from top hose and pull straight out (It’ll be tough). The bottom hose is a bit different. It has a “C” spring clip that opens at the top. Use a flat tip screw driver and push down on the right side (as you look at it). While applying downward pressure, reach under and pull the spring clip off. With the spring removed, wiggle the hose straight off. This may also take a little work.
3231003 Remove upper section of steering column trim
Use a trim tool in the joint between the upper and lower trim on the steering column in front of the steering wheel. Once separated, remove boot by clamping down on retainers and pushing them through the hole. (The boot will remain attached to the dash)
3231020 Remove lower section of steering column trim
Make sure the steering column is in the lowered position, this will make it easier. Unclip, push down and remove.
3231090 Remove steering column
Disconnect three plugs. Two are located near the steering wheel on the box. The third is located lower on the column on the left and is pictured below. Remove two bolts from the lower half (forward) first.
Support the column to prevent it from falling when removing the two forward bolts. (Use a helper). Remove both forward bolts and pull the column out of the vehicle. This will include the lower
linkage arm that is in the engine compartment and the rubber boot at the firewall; it will all come out together. When installing, be sure the boot is seated properly on the firewall.
5145263 Remove instrument panel trim on right side
Use trim tool. There are a couple clips and a couple dowels that seat in the dash. Start from the outer edge to unclip the trim. Then gently work your way toward the middle. Concentrate on pulling the dowels straight out. If you pull to hard or fast, you may break the trim. The dowel is pictured on the left side of the third photo here with the blue receiver.
5116202 Remove both cup holders
2 Philips screws each.
5116366 Remove glove box
T-20 torx bit, remove 6 screws (four across the top and one at the bottom corner on each side) and support glove box as you remove the last screw. Gently lower glove box (there are wires connected). Disconnect 4 electrical plugs (the flashlight is hidden on the far left).
5145185 Remove panel for pedals (under the dash on driver side)
T-20 torx bit, remove three screws and lower panel. Remove the wiring from the clips. Disconnect the speaker, light, MOST bracket, and remove the Bluetooth aerial (don’t disconnect it, remove the whole assembly by unclipping the two retaining clips and lift the unit off the panel.
5145370 Remove left decorative strip on instrument panel
Using a trim tool, start by separating the right side first (next to the steering wheel). The left side may be tough, get the trim tool (90deg) in behind the trim on the left side and pull the trim out. Be careful not to break it (don’t twist the tool).
5145380 Remove right decorative strip on instrument panel
Like with the trim on the left, start by getting the trim tool (90) behind the trim next to the steering wheel and work your way to the passenger side. Be extremely careful as there is a wire connection for the start switch and there is not much slack at all.
5143201 Remove both (A-pillar) roof panels
Using a trim tool, remove the “HPS” cap on both A pillar covers. This will reveal the T20 torx screw you need to remove. Wedge open the top of the cover and get your fingers underneath. Move to
the middle and pull out (toward the center of the car). There is only one attachment clip and it is located in the center. Once you dislodge the clip, manipulate the cover off the pillar. This will reveal both A pillar airbags.
6513060 Remove speaker in dash
Use a trim tool to pop the cover up from the rear (closest to the driver) center first; this will release the rear and sides of the cover. Then carefully release the front and remove. Remove the screws from the speaker. Pry the speaker up and disconnect the wire and remove speaker.
6411992 Remove solar sensor
Use a trim tool to pop off the solar sensor, then disconnect the wire and remove.
6131037 Remove light control unit (Headlight control unit)
Using a trim tool, remove the panel from the dash. Make sure the retaining clip is fully in the down position (you will feel a click), then remove the wire harness. Remove unit.
6411377 Remove A/C control unit
Use trim tool to release a/c unit from dash. Disconnect wires and remove.
6511080 Remove radio
Remove screws on bottom of the radio. Pull slightly out and remove wires. Then, remove radio.
6612100 Remove slide-in unit for radio control key (Ignition key panel and assembly)
Use a trim tool to remove the front cover panel. There are three points, two on the right edge and one centered on the left edge. Wedge out the left side. Use a trim tool to release the clips on the right side and remove.
6211280 Remove instrument cluster
Remove two screws from the top of the cluster. Gently pull out and disconnect plug from the rear. Remove cluster.
5145030 Remove instrument panel trim (dash)
Remove the screws and bolt securing the dash. Disconnect the passenger side panel below the glove box. Disconnect any wiring harness from the dash and gently pull toward the rear of the vehicle.
6411206 Remove Heater Box
Remove the rubber cap for the mounting hardware in the engine compartment (In the center at the top). Remove the hardware.
REMOVE SUPPORT TUBE:
Remove the bolt on the firewall at the driver side next to the a/c lines.
Carefully remove the ribbon from the Styrofoam on the driver side. If you tear this, you will need to buy a new one.
To remove the Styrofoam from the heater support bar, you will see plastic hardware. Simply unscrew these but be careful not to tear the Styrofoam. Some have what look like clips (pictured below) but they operate the same as hardware.
On the driver side by the door, remove the computer from the bar (It’s a white box attached to the front of this bracket and says Siemens on it). Unbolt the hardware on the left and squeeze the clip on the right to remove. No need to disconnect any wires, just remove the box from the bracket. Then, loosen the two bolts on the rear box (pictured and circled). Slide the box up and off the bracket.
Now, disconnect all the hardware from the bar.
Driver side
Passenger side by the fuse box. Passenger side.
Above the steering column. Two bolts.
Looking down from outside the windshield.
Near the center. In the driver footwell.
Disconnect all wiring from the bar. Most of it is held by a ziptie style clip. Do not cut the clip and do not try to remove it. Cut the ziptie and replace upon installation. (If I missed any hardware, my apologies)
REMOVE THE HEATER/AC BOX:
Remove all duct work. It all simply snaps together so look for the retaining clip to release it. There are ducts on the driver side, passenger side, and on the center console. On the center console, you need to loosen the bracket first. When installing this bracket, keep it loose, you will need to adjust it while installing the dash. Tighten the bracket AFTER the dash is installed.
Passenger side ductwork
Center console.
Place a water barrier under the heater lines from the firewall back to the heater box. When you pull the lines through the firewall, you may get some leakage. Gently work the heater lines through the firewall and into the passenger compartment. If you feel any strong resistance, make sure there is nothing holding the heater to the car.
Once the heater box is loose (lines inside the car), pull the boot back giving you access to the lines and remove two bolts allowing you to move the heater lines.
6411208 Replace the heater core
This is the left side of the heater box removed from the vehicle. On the top left you will see to actuator motors, remove them so that you can manually adjust the plastic arm to pull the core out. Remove the two screws on the black plastic covering the core and remove (it has a clip on the bottom as well. Then pull the core straight out of the box with the lines attached. Once removed from the box, remove the clamps from the lines and install the lines on the new heater core. !! WARNING !! Inflo must be positioned at the bottom. When installing, make sure the return-flow (larger opening with a black dot on top) is positioned at the top.
Install everything in reverse. Once all is installed, hook up an OBD program and clear any codes if there are any. I did not include any torques for installation. If they are important to you and you can’t find them, let me know SPECIFICALLY what you would like and I’ll look it up for you.
If I missed any steps, please let me know so that I can correct it. I spent about 16 hours on this and at times “forgot” I was doing a DIY so I was playing catch-up. Feel free to email me with any questions.
Mike