Replacing Oxygen Sensors on an E39 M5

As I’ve stated many times on this blog, when you own a BMW out of warranty you need to learn up on maintenance. With some research and a little effort, you can literally save hundreds of dollars on relatively simple maintenance issues.

A good example is how I recently replaced oxygen sensors on my 2002 M5. The dreaded Service Engine Soon (also known as CEL for check engine light) display had lit up on my dashboard. My code reader told me it was the left O2 sensor in front of the catalytic converter. The E39 M5 has four sensors, two pre and two post cat. So I decided it was best to replace both front sensors.

You can save big on parts before  you ever touch a wrench. The best price I could find from BMW for the sensors was $206 each. A little searching on the M5Board revealed many many owners had purchased the same exact Bosch sensor from Amazon for around $50. A really good tutorial from BimmerDIY was also very  helpful.

So right off the bat, two Bosch 13477 sensors cost me $100, rather than $400.

Old sensor top, new bottom -- exactly the same

Removed sensor

Installation took me less than an hour, and I was working very slowly and carefully. I had also purchased the open 22mm. socket from Amazon to remove the oxygen sensors themselves. The sensors plugged into a small black box on the underside of the car, held in place by two 10mm. bolts. There were two boxes, each containing pre and post sensors on that side of the car.

Sensor box

As usual, my repair was made much easier thanks to my friends at Hollin Hall Automotive lending me access to a lift. While the car was in the air, I replaced the right front plastic underbody piece I had stupidly banged up by brushing against a curb. It was one of those “hard to see but I know its there” type of repairs, and I knew it would be easy to replace.

New underbody panel

The swap was somewhat complicated by the fact that the outside temperature gauge connected into that underbody piece. I was careful with the connector and I closed off the opening with some duct tape.

Old vs. new -- note slot for sensor

New panel in place

I’d estimate that dealers would definitely would charge two hours of labor for this job, maybe even more. At $125 per hour, that’s at least $250 labor and the dealer parts cost of $400. So total of $650, vs. $100 for the sensors and my time on a Saturday morning.

So doing this job myself saved around $550. The DIY satisfaction was priceless.

Upkeep on the 2001 BMW 530

This Saturday I got some simple upkeep done on my 2001 BMW 530. The oil filter needed changing, and I needed to fix the corner of the passenger side headlight assembly, which somehow got pushed slightly out of position.

The oil filter change is very straight-forward, but of course you need the right tools. In this case, that means a custom 36 mm socket with a 17 mm hex head to remove the screw in oil filter canister. (A more traditional 36mm socket will also work.)

Recently Martin Motorsports replaced the Crankcase Case Ventilator (CCV) on my car and changed the oil, but not the filter. Now the car is set on that front for a while.

Ready to remove

Out and ready for new filter

The headlight assembly was a more frustrating mystery. I have no idea how it could have happened. Noticing small imperfections over time comes with the territory when you own older cars. But this wasn’t there prior to the holidays and really bugged me.

The only thing I can think of is that someone nudged the car slightly, but there is no visible impact area. However it happened, once I noticed it of course it really bothered me and I had to fix. Plus, the rubber gasket strip was out of place and I didn’t want rain or snow getting into the headlight area.

Fortunately there are only four 8mm screws that hold the headlight assemblies in place. I needed to buy a six inch extension for the back rear screw, but once I had that it was easy to loosen the assembly and nudge back into place.

Minor stuff, but it’s still a good feeling to fix myself.

What the??

 

Fixed

CD43 Stereo Upgrade for the M3

This weekend I replaced the stereo in my 1999 M3 with a more powerful head unit. In BMW parlance, I went from a C43 to a CD43 radio, the stereo unit included in many BMW models from the year 2000 0n.

A little background to start. It’s widely known that BMW sound systems are not very good, especially for a premium automotive brand. My car came with the Harmon-Kardon premium sound option back in ’99, so it wasn’t horrible.  And I’m no hardcore audiophile. But when the midrange speakers blew in my doors I replaced them with BSW speakers, and the sound improvement was noticeable.

I had read frequently on the BMW forums that the CD43 unit was superior to the C43. It offers a front loading CD, which is nice and more modern looking than the obsolete tape deck. But the real benefit is more power — according to owners who had done the swap, the CD43 could make your sound system sound much better, while still looking totally stock since it was a BMW unit. Supposedly the install was cake — take out, slide in.

Buying a brand new unit didn’t make sense — the cost would have been almost $800. Then I read about an eBay seller offering refurbished units from Europe, and (this was key) some forum members had bought from him and spoke highly of the experience. The price was $225, plus shipping. Now that made sense, and I was sold.

Predictably, it was not as simple as advertised. There must be BMW engineers in Munich scheming to make such things as complicated as possible. One example — the screw heads securing the radio units in US E36 cars are a proprietary design — not phillips head, not flat head, not allen wrench. Really, BMW? In this day and age of globalization and efficiency through standardization, you need a special screw head design for North America?

That delayed my project — I had to order a special removal tool, $17 from Bavauto. So I tackled the install this Saturday. Once I had the tool, it was easy to remove the unit. It’s weird to see a big hole in a dashboard you’ve looked at for years. The radio connection and ground were obvious, but the fuses and power were damn difficult to unplug. I was very reluctant to use too much force and break something. The heat being in the triple digits even in late afternoon didn’t help matters and added to the frustration.

Some tugging and sweating later, it finally came loose. After that is was straight-forward to plug in the new unit, and slide back in. Then I ran into some fitment issues with the new unit. It wasn’t exactly the same depth as the original, and I had to play around with the wires so the CD43 went flush. After it was installed, I used a printout the seller sent me to program the unit from Europe mode to the good old US of A.

Thankfully, I can say the effort was worth it. The radio reception is much crisper, and a lot louder. The CD sound is also improved, not as dramatically as the radio but the bass sounds in particular are better. And being a BMW unit, the illumination is an exact color match to the rest of the dashboard components.

It’s one more subtle, useful mod that helps make my E36 M3 the best car it can be.  And despite BMW’s needless complexity, I was able to enjoy DIY satisfaction.

New (to me that is) CD43 Unit

Unit out

Crap, how does this unplug?

Hmm, not EXACTLY the same

Got it!

New Fog Bulbs — Easy DIY

When owning an older BMW, it’s smart to discover the small maintenance items you can take care of yourself. Of course, what is easy for one person isn’t necessarily easy for another. In fact, it’s wise to approach with caution many projects some guys on the online boards say are incredibly “easy” to do yourself.

However replacing the fog light bulbs on an E36 M3 truly is easy. My driver side went out last week and I replaced both bulbs this weekend. The bulb size is H1 and I like using Osram (Sylvania) SilverStars purchased from PowerBulbs.com: http://tinyurl.com/6tz2tk

They are much brighter and the light is whiter than stock bulbs, and since the dollar has come back against the pound the price is very competitive.

First step is to insert any type of screwdriver through the brake duct and disengage the fog assembly clip. It’s simple, and when you pop the clip the fog light comes straight out:

Step One

Out It Comes

Then just take off the plastic housing, and unclip the two springs that hold the bulb in place:

Clips

Opened and ready for replacement

Then slide back in and push until it clicks back into place:

All Done

Voila, all done in about ten minutes. It’s easy to learn how to replace all the bulbs on these cars, and even something small like this gives a nice DIY feel.