dvintglk

Just got a 2014 GLK350 4Matic. It doesn't need a oil change right now but I always used Mobile 1 on my previous Mercedes. Any thoughts with the GLK? Just use standard oil? Also, I dont think there is an issue with draining out all the old reg oil and replacing with a synthetic correct?

Racin_fool

It should have come with synthetic unless someone swapped it out before you purchased the car.

dvintglk

I bought it from a used dealership not a MB dealer. There is a sticker noting next mileage for oil change but not what oil weight was used. Guess I can try to call and find out. If they used regular oil is there an issue with swapping back to synthetic?

JohnnyC

there will be no issues. if you run non-synthetic the oil will degrade quicker leading to more frequent oil changes which will negate any cost savings. Mercedes vehicles have always been required to use full-synthetic, not a blend or conventional.

KC61

First thing I do after I buy a used vehicle is change all the fluids and filters and yes, Mobil 1 .

Mmr1

C300fan2

like everyone else said, change it! My new to me GLK 250 i purchased 4 months ago just had an oil change done, I knew because it had a oil sticker on the windshield. The GLK 250 takes special mobil 1 oil and I knew they didnt use it so I changed it right away.

JFATX

I've seen some DIY videos on the GLK showing users also replacing the smaller o-rings on the filter stem. Is this really necessary for every oil change? Any risk in not changing these?
I ask in large part because the replacement filter (from Purflux and also in the OEM filter pics in this post) only includes the larger housing O-ring. Some users go with the aftermarket Mann filter which includes these smaller o-rings in the package.
Does the dealer always replace these o-rings on the filter housing stem, and if so is this a separate part number (didn't see it listed on a dealer invoice from a previous scheduled service visit).

Grip Grip

[QUTE=JFATX;7809313]I've seen some DIY videos on the GLK showing users also replacing the smaller o-rings on the filter stem. Is this really necessary for every oil change? Any risk in not changing these?
I ask in large part because the replacement filter (from Purflux and also in the OEM filter pics in this post) only includes the larger housing O-ring. Some users go with the aftermarket Mann filter which includes these smaller o-rings in the package.
Does the dealer always replace these o-rings on the filter housing stem, and if so is this a separate part number (didn't see it listed on a dealer invoice from a previous scheduled service visit).[/QUOTE]

I'd change them to be safe. I've never had a filter not come with them, so that's a new one for me.