I fix something and something else goes bad. The car runs great (when nothing is wrong), so I have no intention of giving up.

I am approaching 150k and these are the parts I have changed over the years

1. Oil and filter change every 5k miles (since 100k)
2. ATF at 105k, 130k (twice at 130k due to gasket related leak)
3. Balljoints lower (twice) and upper - last at 120k
4. All air suspensions (Arnott) - at 130k
5. Engine and transmission mount twice
6. Brake pads thrice
7. Central Gateway (or ECU or something like that) due to dead battery - Mercedes of North Houston lied, it turned out to be just the Alternator
8. Alternator (dont change the voltage regulator alone, does not last long)
8. Main battery thrice (stock lasted 11 years, second 2 1/2 years) - all MB genuine
9. Aux battery
10. Thermostat (preventive) and second coolant flush
12. Steering fluid (at 110k) - preventive
13. Differential fluid (at 110k) - preventive
14. Control arms TRW at 140k - preventive
15. Tie rods inner and outer at 140k - preventive
16. Thurst arms twice (last at 120k) - preventive
17. Front wheel bearings at 130k - mild play
18. SBC pump - recently using 25 year unlimited warranty
19. Tires fourth set I think
20. Crankshaft position sensor at 105k - have a new one handy
21. Heater change over valve - long time ago (at 80k or so)
22. Wiper blades
23. Coolant temp sensor - preventive - car complained too hot when driving across Arizona in July
24. All spark plugs and wires - preventive - at 100k
25. Stabilizer bar links - front - preventive
26. Idler pulley - preventive
27. Serpentine belt - preventive
28. Tensioner pulley - preventive - but went back to the original one, the new one was wobbling a bit
29. Cleaned MAF
30. Cleaned throttlebody (as best as I could without taking out)
31. Door actuator both drive and passenger (just replaced the tiny broken spring)
32. Brake rotors twice
33. Breather case oil leak fix (at 115k)

These are the parts I have ordered (all preventive) - please tell me if any of these is not required
EGR valve kit
MAP sensor
Knock sensor
Camshaft position sensor
Oxygen sensors (all four)
Secondary Air pump (got P0410 recently)

These are on my list but not sure if I should do them unless they go bad
Water pump
Brake calipers
Brake hose
Fuel filter/pump (scary looking job)

Anything worth looking into at 150k miles as preventive maintenance?? I want to do the brake calipers and brake hose but dont have STAR, I have iCarsoft MBII scanner though.

Except tensioner pulley, all are OEM or genuine parts from FCP Euro. Currently getting 24 mpg doing 80 mph, was getting 27 to 28 mpg when the car had 90k miles. 95% of the work DIY, can't afford doing it all at dealership.

 

I was doing a quick cost calculation - $80k for the car (with interest and other payments), $4k at dealership services and 6k on DIY parts. That's $90k over 15 years. $6000/yr or $500/month to own a E-Class.

Sounds like leasing every three years puts you in a better position??? GLA250 can be leased at $600/month (they market it as $329 but out the door will come to $600 per month). Perhaps leasing for 5 years will have you drive a new car every 5 years for about the same price of owning.

 

For the oxygen sensors I would just get two, the upstream ones. The downstream ones don't really go bad. The upstream ones are the ones that get fouled up from the raw exhaust, the downstream ones come after the converters have done their job so they're not stressed as much as the upstream ones. When the downstream ones go, that usually means you need new converters. If you don't end up with any emissions issues, they should last the life of the car. Can't say that for the upstream ones.

Unless you have issues with the brakes, I wouldn't bother with the calipers.

As for your numbers, it's much cheaper buying them used. When you hit 155k, don't forget to get your high mileage badge from MB.

https://www.mbusa.com/mercedes/herit...ghmileageaward

 

P0410, if you check the air pump, fuse and relay are working fine, then you may just need to clean out the air passage. It does get clogged up. Also, if after doing all this, it may be the upstream o2 sensor that is not responding properly. So if you already have a new air pump, put that in, make sure the fuse and relay is working, and clean out the air passage. If you already have new o2 sensors upstream, pop those in as well. Then everything should be good. Also, the small rubber hose that connects between the two sides, you can easily replace those with hoses from the local auto parts store.

 

Yeah but you’re assuming you’ll need to do half that stuff again, you likely won’t for another 100k and your costs should drop for the next couple years.

 

Thanks for the advice. I will do just the upstream then.

 

Thanks for the tips. The secondary air pump IMO (for what it does) is the stupidest thing and super expensive That said I think the pump is groaning after starting the car, stays groaning for 30 seconds or so then idles as usual. I read that the pump only runs for a few seconds after starting the car, so the groaning is likely from the pump. It is the pump that is having me go after O2, EGR and other sensors and do preventive maintenance.

 

Hmm... that's how we pump money and it is always something else that surprises you

 

here is the pic of the Badge on the car