I purchased new GLC 300 4matic in June 2017.
Since a month I am observing , one of tyre is loosing air slowly - 1 to 2 PSI every other day. I have to refill air every 4 to 5 days in that tyre. I change valve stem but no luck. I can diagnose and repair tyre by myself or at local tyre shop but just checking - if this is covered under warranty since car is less than 1 yr old ? Can I take car to dealer and will he fix it free of cost ?

I live in NJ and did not take any maintenance package from dealer when I purchased car.

Tyres are consumables and not covered by warranty, best you can hope for is the dealer will fix it as a goodwill gesture, speak to them and see what they say. You say it is only the past months it has been leaking so may be a slow puncture.

Good advice. Wouldn't surprise me if the dealer repaired the tire as a good will gesture. Otherwise, expect to pay on the order of about $25.00.

thanks all. Not worth to talk to non responsive dealer for $25. Will visit local mechanic .

Have you checked to see whether the rim is cracked? The rubber might well be fine...

Doesn't look like it was Rim. I do not see any sign of crack either on Rim.

I changed another valve stem yesterday. Seems it is holding air as of now. Today, just to be sure, I removed tyre and immersed it in a big water container. Watched it for 15 mins. No sign of bubbles anywhere. So most probably it was valve stem. I replaced earlier but I might not have tighten enough or it was faulty too. Will keep monitoring. Thanks everyone for suggestions.