We just picked up a 2009 R55 N12 6 speed a couple days ago for the missus as a fun little toy. It runs nicely; smooth, quiet and reasonably powerful for what it is (certainly enough power for the wife to have a little fun with).

But it's got 118,000 kms (approx 73000 miles) on it and the service history mostly indicates routine maintenance. So the car is essentially as BMW delivered it on it's first day.

I'm a big fan of preventative maintenance and there seems to be a couple items that can fail at higher mileage, some without warning.

So, I'm looking for some input on items I should look at replacing on spec.

Being an N12, it seems like it doesn't have some of the items that are failure points like the high pressure fuel pump or the "aux cooling fan" issues you would have on the "S" models.

I've read a couple things on the vacuum pump locking up on N12' and wiping out the engine (I assume it must lock the valve train and then all kind of gremlins would get loose in a zero clearance engine).

The timing chain is another point, but it seems that it gets noisy before it packs it in. I'll probably start buying up bits (ie:chain, tensioner, guides, oil pump chain, seals, etc) so I have them on hand as well when it comes time to change them.

I've already ordered the foxwell NT530and the cam locking kit, mostly on spec so I have it on hand if/when I need it. Cam locking kit just made sense as it seems you need it to do nearly anything in the top end of this little bugger and I may have to do valve seals soon as it does have a little puff after idling for any extended period.

I'm looking to make this little rig as reliable as possible as it's my wife's little fun car and I'd like to have my own peace of mind that she's driving it in as dependable condition as I can make it.

So, suggestions?

 

I bought my 2008 R55 N12 6 speed with around 52,000 miles in May 2017, and due to my long commute it now has over 170,000 miles. I've been concerned about the timing chain the whole time, but I haven't had to replace it yet. I never trust previous owners to use the correct oil, so the first thing I usually do is change it with on spec oil. I've been using Liqui Moly Top Tec 4200 5W30. And I change the oil every 6,000 miles or so. And I keep the oil topped up. I usually have to add some once a week.

I replaced the water pump at 106,000 miles. I used Hepu brand. I did wait until I saw a little drip of coolant, the sign of it starting to go. I replaced the thermostat housing at the same time, not because it needed it necessarily, but I had picked up the part early on because I read somewhere about it being a point of failure (perhaps misguided, I'm not sure). I replaced the water pump drive wheel (OEM / Dayco) and of course the drive belt (Continental) at the same time.

I always use 91 or higher octane fuel (usually 93) and add a 10 oz. bottle of Chevron Techron fuel system cleaner every 5,000 miles or so. I've replace the fuel filter 2x once at 64,000 miles and again at 144,000 miles.

Other than the other routine maintenance, air cleaner at 20,000 mile increments, (Mann) and cabin filter at the same time, and brakes, etc. I've only had a couple of quirky problems. One with the footwell module (the reverse light stayed on ALL of the time) so I replaced it with a used part. Also had a problem with the power steering. I replaced the electronic unit (OEM). I think these problems were because the first owner drove the car into water and it corroded things. The power steering was so bad, the main plug was stuck and once I finally removed it, found almost nothing left of the contacts - all corroded. Had to replace the harness as well.

I'm no expert, but I've managed to keep it going so far.

Hope this helps. I keep a detailed spreadsheet of maintenance, if you have any questions about anything else.

 

I am most interested to to know what the compression is, leak down test and how often you replace plugs....

 

Well, this is interesting:


Making a block off plate is a fairly easy job for me too.

I think I'd much rather have an electric pump die and make the brakes a little harder than a mechanical pump "packing it in" and snapping off the exhaust cam sprocket.

I'll have to dig into the system architecture first though and make sure it's not going to create it's own set of problems (IE: is the cam end now unsupported, etc)

 

To answer thefarside questions, never did a compression or leak down test. I replaced the plugs following Mini guidelines at 100,000 miles, using Beru plugs. Plan to replace again at 200,000 if I get that far!

On a side note, I installed 'high performance ignition coil set' made by Bavarian Motorsport (made in China) at 127, 282 miles and was disappointed. Upon initial install, the hold down clip on one of the coil packs broke when applying pressure to clip it into place. I had to pull them off at 161,969 miles in order to replace the valve cover gasket (oil was getting into the spark plug cavities) and more than one of the coil packs broke apart (the rubber boot tore). I ended up using the original coil packs made by Bosch until I put on a new set also made by Bosch (made in Slovenia) at 169,801 miles. And I never noticed any significant difference in performance or increase in MPG, the later of which I track meticulously.

 

At 73K, my Justa was doing pretty much everything right. At some point around 80K, I had misfire issues in a couple cylinders. Replacing the plugs and coils solved that. Overkill, but I hate chasing stuff like that.

At 93K miles, I'm just finishing doing pretty much everything in the suspension - shocks all around (along with all the soft bits, shock mounts, etc.), stabilizer and steering links, front control arms with urethan bushings, rear upper and lower control arms, etc. I probably could have done this earlier as I think one control arm bushing and a shock mount were probably in need of replacement for a long time, and frankly I wish I'd done it sooner - the with Koni Special Active shocks and everything else new (even new Pirelli Cinturato P7 All-Season Plus II's - which are the quietest damn tires in history), it takes away a hard/jarring edge to the car that I already am happy to see gone.

The last bit was the rear control arms, and went with the Hotchkiss Adjustables. Even though I don't track the car, it's nice to have adjustment that easy in the rear.


So I guess what I'm saying is suspension is something to start thinking about. I did all that myself, so doing it all at once felt right.

I'd also keep an eye on the oil pan and valve-cover gaskets - those are in-hand and the next things I'll do. Then I have to decide whether I'm going to tackle the water pump (doesn't look too bad) and thermostat (doesn't look fun at all...) or have it done. (I'm cheap. I'll probably do it myself)