Sanjayna

Just had the 50K service A done on my 2015 C300.
Dealer recommended changing spark plugs for $550. When I pushed for details, the breakdown was $100 for 4 spark plugs ( Q-4-15-0038) and 2.5 hrs of labor.

Has anyone else replaced the plugs at 50K miles and what was the cost? I thought spark plugs had a much longer life than 50K miles..

Tom in Austin

I believe normal plug life on newer cars is in the 100k mile range. This is partly because federal emissions warranties go pretty far out in mileage terms, so the mfgs have all moved to a plug life that ensures they won't have to pay for new parts to keep the vehicle in compliance during the emissions warranty period. I know my wife's Honda recommends plugs at 100k.

You might take a look at the discussion of emissions warranty for your car and ask the dealer to reimburse the plugs as a warranty item. If they truly needed to be replaced, you would think the vehicle emissions were affected.

xsever

What does your owner/service manual say for spark plugs? For the W204, it's 60,000 miles or 6 years, but your car is a W205.

You might get better answers in the W205 section by the way.

gamma300C

https://www.pelicanparts.com/catalog...BASTUN_pg1.htm

Definitely a DIY job if you want to do it... A Search will bring up the procedure somewhere on the Web. The M276 engine says 60K miles for the plugs but I think that's because it's a Direct Injection engine..probably to soon. My M272 has the 60K interval and the iridium plugs look great at that mileage. Fairly inexpensive to change though but would invest in your own plugs/thin wallws socket. Torque is 16 NM-23 NM with the higher end preferred. A Torx (T30?) bit needed for the COP bolts.

markmatt

Maybe this will help.

ItalianJoe1

They are suppose to be done at 50k, but that labor is a bit high.

MB_FanAddict

For reference, here are the maintenance intervals for a 2015 C300 sedan. In addition to spark plugs, the engine air filter is also due at 50k or 5yrs.

Service "A" (10,000 miles or 1 year)
- Engine oil and oil filter change
- Replace dust filter

Service "B" (20,000 miles or 2 years)
- Engine oil and oil filter change
- Replace dust filter
- Replace activated charcoal cabin filter
- Rotate tires (if applicable)
- Flush brake fluid

50,000 miles or 5 years
- Replace engine air-filter
- Replace spark plugs

60,000 miles or 6 years
- Automatic transmission oil and oil filter change

120,000 miles or 12 years
- Replace fuel filter
- Replace coolant

ItalianJoe1

The A service calls for the dust filter under the hood, the B service is that one and the cabin filter under the dash.

MB_FanAddict

Glad you caught that! I edited my original post.