E36 heater core replacement

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BMW Heater Core Replacement, David LaBarreare, ImportCar, August 2001

Despite all the advances in automotive technology and manufacturing in the last couple of decades, we, in the auto repair industry, still experience failures of heating/cooling system-related components. Radiators, water pumps and hoses are all easily serviceable items for the most part. On the other hand, heater core replacements in the BMW E36 are anything but a routine, straightforward repair but, hopefully, with the help of this article you will be able to make it a profitable venture on the first try.

The indicators of a leaking heater core are the same symptoms that you have come to expect — a sweet smell in the interior with the defroster fan on, an oily film on the windshield, perhaps a leak out of the evaporator condensate drain or a slight mystery coolant loss. Always inspect the evaporator condensate drain located above the transmission bell housing.

BMW has updated its radiator cap specification from a 140kpa to 200kpa (new p/n 17 11 1 742 231). This new cap is designed to control pressure and provide greater coolant overflow in the event of overheating.

WHAT TO CHARGE
This is always a debatable item at our shop. Certainly, the vehicle’s age and state of cleanliness factors into this equation. Generally speaking, the job pays anywhere from seven to eight hours depending on which labor guide you use. The car used in this article is a 1994 325is Coupe. Other E36/3 Series cars may vary slightly from our example, but the details provided in this article should give you an idea of the job’s scope. The parts required to carry out a heater core replacement are the heater core, tubes and O-rings. See the accompanying chart for part numbers, quantities and current list prices.

REMOVAL/REPLACEMENT PROCEDURES
1. Once you have confirmed that the core has a leak and the job has been sold (usually with a short completion deadline), get yourself into the proper mindset by starting with some calisthenics and stretching exercises. Underdash work requires some of the most demanding and uncomfortable work we do as technicians. Also take the time to undo the heater hoses and blow them out with compressed air.

2. Drain the coolant system. This is best accomplished by draining the cooling system from the block. All M50 6-cylinder engines have a 19mm hex head drain plug on the right side of the engine block. There is also a radiator drain screw on the left side of the radiator that can be removed for a more thorough draining of the system.

3. Disconnect the battery ground strap. The battery is located in right rear corner of the trunk.


4. Remove the steering wheel air bag held on by two torx head screws on the rear facing side of steering wheel (See Photo 1). Unplug the air bag plug by pulling outward. Place air bag assembly face down in the trunk for safety purposes.

5. Remove the left lower dash cover and lower steering column cover.

6. Remove the steering wheel retaining nut (either 16mm or 22mm hex) and remove the steering wheel. Make certain the directional signal in not activated or you might break the canceling pawl. Take care not to pull the steering wheel out too far without disconnecting the orange air bag contactor ring plug. This contactor ring is very fragile and can be easily broken, if mishandled (See Photo 2).



7. Remove the glove box by removing the six Phillips head screws, two of which may be covered by the interior colored trim (See Photo 3).

Note: There are two styles of glove boxes. The later version has one additional 10mm hex head bolt located above the glove box light.

8. Remove the right-side dash lower trim.

9. Remove the passenger-side air bag (if equipped) and store it in the trunk with the driver’s-side air bag unit (See Photo 4).

10. Remove the steering wheel upper cover.

11. Remove the driver’s-side lower valance panel (under steering column). There are two Phillips screws on the top edge and one Phillips screw at the bottom right-side corner. Pull the panel out of the car from the left side.

12. Remove the dash light dimmer switch panel.

13. Remove the driver’s crash protection knee bolster held in place by three bolts (See Photo 5).

14. Remove the two special anti-theft fracture bolts from the steering column, so that the entire column can be dropped down. We use a hammer and small, sharp chisel to back out these bolts. Also remove the through bolt in the column tilting bracket, making note of the spring clip attachment. Lower the column down.

15. Remove two torx bit screws (sometimes Phillips head screws) from the upper instrument cluster mounting flange. Pull the cluster toward you and finish removal by unplugging the three color-coded plugs.



16. Remove the headlight switch and vent assembly by removing outwardly visible Phillips screw and hidden screw accessed through the instrument cluster opening.


17. Remove the anti-theft radio with special BMW tool #82 11 1 466 971 (current list price of $13.87). (See Photo 6) This is a good time to determine if the customer has the radio security code. Usually there is a small credit card-style card included in the manual set with a five-digit code as well as the radio chassis number written on it. This may or may not be the correct security code number, as many of these radios get replaced. In any case, go ahead and record the radio chassis number so that it can be verified or called into your local dealer to obtain the correct five-digit security code.

You must refer to the BMW radio owner’s manual for the correct security code entry procedures. Failure to address this issue will result in a complaint call from your customer, claiming you have disabled his/her radio.

18. Remove both A pillar post covers by pulling straight out from the pillar post at the top, then sliding the cover upward to release the bottom retainer (See Photo 7).


19. Remove the upper vent assembly by removing the two Phillips head retaining screws with a short/stubby screwdriver (See Photo 8).

20. Remove the upper vents by removing the two 7mm hex head bolts. We use a 90-degree carb tool with a short 7mm socket to facilitate this operation (See Photo 9).


21. Remove the dash fascia (See Photo 10). Be sure to remove the two 13mm hex head bolts at the far lower corners of the dash.

22. Remove the climate control panel by removing the four knobs and Phillips screws under the two large knobs. Remove the front fascia and pull the control unit out from the rear through the radio opening.

Note: You may have to disconnect the cable from the right-side air distribution control knob.


23. Remove the seven bolts from the perimeter of the heater core case cover, unclip the wiring harnesses and unclip the actuation lever. Remove the heater case cover to expose the heater core.

24. Remove the 10mm hex nut on the heater core piping flange.

25. Remove the three 10mm hex head bolts and the three-way piping flange (See Photo 11).

26. Remove the heater core by prying out the core toward the front (See Photos 12 and 13).



Complete the job by installing the new heater core unit and reassembling components in reverse order.


with pics here
http://www.babcox.com/editorial/ic/ic80136.htm

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Unfortunately the link does not work anymore. Did somebody download it with the pictures? If so, please post the pictures.

Here is another link with pics
http://forums.bimmerforums.com/forum....php?t=1433591