During the second week of January, we passed the one-year mark since we brought home our 2015 BMW 435i project car. And while we’ve detailed the performance modifications we’ve done, we haven’t talked that much about the more mundane tasks of simply maintaining the car for daily use.
Our friend Rennie Bryant from Redline Bimmer has a saying: “BMWs are 100% reliable as long as you fix everything that breaks.”
It’s clever, but there’s truth hidden in the dark comedy there. While BMWs are typically robust and durable, when something does go wrong, their inherent complexity can make fixes costly, complicated or both.
And the thing BMWs hate the most is deferred maintenance. Problems left unaddressed tend to compound logarithmically into more and hairier situations.
That’s part of the reason that there are so many seemingly great deals on used BMWs. Cars come off warranty and owners are faced with costly maintenance, so they either put it off or just bail out of the car and let it be someone else’s problem.
Well, we can’t solve all the world’s problems, but what we can do is talk about what it was like keeping our BMW going for a year. With just over 71,000 miles on the clock when we bought it, we knew it was hitting a period when a lot of things were going to be recommended, so we were emotionally prepared for the process. We’ll let you be the judge as to whether or not our experience was worth the hassle, though.
We’ll also say that this process was made far easier by having BimmerWorld on speed dial. As I mentioned, BMWs are complex creatures, but BimmerWorld has almost every model figured out. While the parts availability alone is worth having that number handy, the real benefit is the knowledge base. “Oh yeah,” the friendly voice at the other end of the call will say, “Definitely do this other thing while you’re in there.” We love that stuff.
Back to that deferred-maintenance thing from earlier: The more you can get on top of things that will likely go wrong in the future, the better off you can be.
This is probably also a good time to mention that if you’re going to own a modernish BMW, you may need some specialized tools as well. And by “may” we mean “will.” Fortunately, we already had a lot of what we needed in our boxes, but we did have to add a set of E-torx bits. We got this one for less than $25, and it’s held up all year, so we’d call it a win so far.
Photography Credit: J.G. Pasterjak
Belt and Tensioning System: $100.99
The first issue we ran into was during our first track test: Our serpentine belt was shredded due to the idler pulley seizing.
BimmerWorld’s Phil Wurz recommended that we replace the tensioner at the same time since we’d be in the neighborhood. BimmerWorld sells a complete kit to do the job and welcomes us to the wonderful world of “While you’re in there…” jobs that BMW owners know so well.
[Surprise: Our BMW 435i broke a belt during its first track day]
This one is a fairly straightforward DIY as well, but you will need to get under the car to thread the belt through the tight gap between the crank pulley and engine.
Door Lock Actuator: $500
This one stung. Our driver-side door lock actuator failed, meaning that we couldn’t lock the door we most frequently use.
We had this one handled by the crew at Spiker Motorsports. The part was around $250, and labor costs to install were around the same.
Optima Battery and Adapter: $380
“If your BMW is doing weird stuff, the first thing to check is the battery,” Wurz told us. “BMWs are notoriously hard on batteries. There’s a lot of complex electrical systems, and a lot of systems that draw some small amount of power even when the car is shut off.” In fact, he recommended that we replace our three-year-old battery before the issues really cropped up, so we did. (In fact, if the car sat for three or so more days, there was no better than a 50/50 chance it would start without a boost.)
BimmerWorld recommended an Optima Yellowtop, citing the Optima’s additional capacity as a great weapon against the BMW’s tendency to overtax batteries.
Photography Credit: J.G. Pasterjak
The 435i is originally equipped with a DIN H8 battery, which is a big sucker. The Optima Yellowtop H7 offers both more cranking power and more reserve power than the OEM battery but in a slightly shorter and lighter package.
So BimmerWorld whipped up a custom hold-down that allows installation of the smaller-but-more-powerful DIN H7 Optima into the car’s DIN H8 slot.
Photography Credit: J.G. Pasterjak
The Optima retails for $359 and the BimmerWorld adapter costs $20. Installation is simple, but remember that you’ll need a scan tool to code the battery to the car and the car to the battery, and not every scan tool has this functionality.
Cooling System Maintenance: $830
This was the first of our more major “While we’re in there…” jobs. “We see a lot of these electric water pumps go around the 75,000 mark,” Wurz told us. “Figure any mileage above that is a gift. So we recommend finding a way to do the coolant control stuff at or before that mark as preventative maintenance.”
Plus, we were in there anyway.
When we upgraded the oiling system–which necessitated removing the front subframe and disassembling a good chunk of the engine from below–we had easy access to the water pump, thermostat and auxiliary coolant pump.
The BimmerWorld water pump and thermostat package is $575 and the auxiliary coolant pump is $255. None of these parts are sexy, but neither is being stranded with a failed coolant pump.
Photography Credit: J.G. Pasterjak
Ignition Coils: $165
Unlike the coolant pumps, where Wurz recommended that we stay with OEM parts, he recommended Delphi coils when we had a coil fail during a test day. “We have great luck with the Delphi coils, and they’re cheaper than the OEM ones” was all we needed to hear from Phil to convince us.
Indeed, the Delphi coils he recommended at $33 each cost less than half the price of OEM BMW coils, so we were glad to save a few bucks there.
Photography Credit: J.G. Pasterjak
Diagnosing the bad coil was simple. We felt the misfire during a track session, and the ECU showed the misfire on cylinder 1. We swapped the coils from cylinders 1 and 2, and the misfire followed the coil to cylinder 2, showing us the coil was the issue.
Wurz’s recommendation was to replace all six: “If one is aging out, they’re all the same age…” We couldn’t argue with that, so we did all six coils and kept a couple of known good ones as spares.
General Maintenance and Fixed Costs: $???
This is a tricky one because it’s always going to be variable based on your situation. Fox example, we’ve gone through a bit more Red Line Oil on this car than we might normally because we took the engine apart to replace the rod bearings. But we can give you a few data points:
An oil change kit with Red Line Oil and a Mann filter, which is the combo we’ve been using, cost $119 from BimmerWorld. A transmission service kit retails for $185.
Photography Credit: J.G. Pasterjak
Obviously that transmission service kit is going to be needed less often than the engine oil kit, but we still did a full transmission fluid change as part of our post-purchase service. We also did Red Line fluid in the differential, so tack on another $40 or so for that.
Photography Credit: J.G. Pasterjak
As for daily costs, we averaged just over 21 mpg for the year, including our trips to the track. We drove the car not quite 3000 miles, so we figured a little less than $600 in fuel for the year.
Insurance for the car seems to be on par with other late-model automobiles. Remember this is for a 54-year-old Florida driver with a good record, so your results may vary, but we found no “BMW bump” in the insurance cost for the car over “normal” cars.
Doing some quick napkin math here, we’re right in the neighborhood of $2000 for maintenance and repairs on this now-10-year-old BMW. And at least some of these items will hopefully be one-and-done expenses for our ownership of the car, like the coolant pumps.
So, is that good? Bad? We’re not sure. It seems reasonable given the BMW's reputation for being costly, and we certainly can’t argue with the level of driving experience it’s delivered both on track and on the road.
We’ll see what year two brings and continue to enjoy the reliability of our BMW by fixing everything that breaks.
