Hello Scotty, greetings from Europe. I have a 2002 Škoda Octavia 1.6 AVU (which is essentially a Jetta with a 5th door) that started to burn oil (~1.5l for 6000 miles of 10w-40). On my last oil change an "excellent" mechanic, unbeknown to me, swapped 10w-40 for 5w-30 and now it burnt ~1.5l for 1700 miles. Should I change the oil for 10w-40 now or at the next oil change (in ~5000 miles) or should I continue to use 5w-30 or something else completely? Thanks!
Stick to the recommended oil viscosity for your car. Using heavier oil is not a solution for oil burning issue. Changing the PCV valve and using some oil cleaners are the cheapest way to help the situation, otherwise you might need to rebuild the engine.
So, I should change the oil immediately to the recommended one?
Yes.
I would put in the correct oil immediately.
Thank you guys.