After 100k Miles, Plus Towing
 

My 2009 35d just rolled to 107,000 miles, and my extended warranty of course expired at 100k. I have been debating keeping the vehicle for much longer, but it still does so many things well.

I haul a 5000 lb / 2300 kg travel trailer (caravan) since 2012, and have been really impressed with the diesel’s towing performance and towing mileage (approx. 17 MPG). It has the factory hitch and brake controller assembly. I tow an average of 1000 miles per year.

Apart from routine service, in the past seven years the X5 has gone through a battery, a throttle switch, an idler pulley, brake pads, a new DEF heated tank, and a DEF software module reload. I chose to refresh the transmission fluid at 100K miles - after much discussion with my SA, and reading this board - as well as a cooling system flush and fill at 50k and 100k miles.

The SA pulled the intake at 100k, and was surprised that I had practically no carbon build-up. He was surprised, and figures there must be something different about my driving style, as most diesels he sees here in Texas have major CBU issues.

The month, during an especially hard trailer summer towing trip of over 2,000 miles, the “Reduced Engine Power” self-preservation mode kicked in during on particularly steep mountain pull. It reset itself at the next fuel stop, and has not recurred either towing or not towing in three weeks. No codes generated.

The service shop owner says he sees a half dozen X5s with over 150,000 miles on them, and says I should keep this one. What do you think about the lifespan of such an ’09 diesel?

Overall, diesel engines are extremely reliable. They make the blocks and components extra strong due to the high compression required to ignite the fuel/air mix in the cylinders. My greatest concern about high mileage diesels (like mine which has 92k on it) is the emission equipment. Parts such as the NOx sensors (I was quoted $1800 to change both) and Urea system scare me a little. I think in the later model years they got it down a little better but the first few years were tough from what I've heard.

Regarding the possible effects of your constant towing, I think that probably help reduce carbon build up in your engine, as the increased load helps the engine burn the fuel more complete reducing carbon build up. I actually think the reason they took the 35d out of the much lighter 3 series was b/c the engine didn't have enough load, which was causing tons of carbon build up. Now they use a four cylinder turbo diesel in the new ones. Towing would have more of a negative effect on your transmission if anything. Have you serviced yours regularly? I guess the wear on your transmission depends on how often you've changed the fluid, how far you tow, and how close you are to the max limit when you tow. I don't have a clue about turbo reliability lol. So I guess to sum it up, it depends! But at least you have some factors to consider.

Sounds like a solid diesel. Mine has 120k on it and knock on wood has been great. Serviced at dealer till 100k. I need to do trans fluid soon and coolant flush but besides that its all good. I plan on keeping as long as it financially makes sense.

Do you have emissions in Texas? If not, you can always get rid of the clean diesel parts and tune it, that thing will last you for a long time after that and will tow even better.

What did you use to scan for codes? I always get a code when I get the idrive message. Usually it is nothing to worry about as towing can do odd things. It could be as simple as your transmission was getting warm and the ECU was limiting torque to protect it until it cooled down. I tow in DS around town to keep the RPMs up.

You and I have replaced nearly all the same parts but I also replaced my engine partition last winter. That one is important because it keeps water off the injector wiring.

Are the 6 X5s with over 150K miles diesel or non-diesel? I would suspect those are non-diesel. There is just isn't enough real-life data to support how long the X5 diesels are lasting/cost. That being said, it looks like you haven't had a lot of red flags as far as issues so I would stick with it.

Thanks for all the feedback. Makes me feel better about pressing on, despite how many times the sales dept sends me messages about great trade in opportunities for a new X5!

That surprised me too. The service shop checked for codes, though I don't know which machine they use. I didn't try my basic reader, as I was taking it in for service anyway. A towing anomaly fits the circumstances, but its always freaky when the system complains at a bad time.

Great idea, as Texas has emissions testing only in select jurisdictions. We currently have only safety inspections here. I've read some pretty impressive specs on chipped diesels.

Yes, only of the six is a diesel. Your comment is right on target: we just don't know about the diesel's longevity, and I'm not usually the guy who does the long term testing! :D

Read this if you havent already.
http://www.xoutpost.com/bmw-sav-foru...lash-tune.html

I thought over the pond diesels run a very long time.It's the soot going back in the engine that will shorten it's life.Is there any info of anyone sending in oil analyst?

great success story and a bit encouraging. There seems to be no high mileage E70 diesels (over 150) state-side at the moment, looking at available Autotrader listings....

130k on our 2010 X535d and solid as a rock. Emissions garbage is the cause of CEL, but runs great and averages 26-27 mpg. We don't have e-testing here (yet). Soon to be tuned