I found out that there is some oil in the intake manifold. Are there any possible sources of oil leak into the intake manifold beside the breather hoses? Photo shows MAP sensor...
Replace your PCV valve should resolve this issue. It is located under the engine. You will have to raise the car and look under the engine to get to it. Also replace your MAF sensor unless you can clean it sufficiently without damaging it, if you do replace it get a good one, not one of these cheap ones from Ebay
Thanks! I'm planning to get to the PCV valve (that's the one under the compressor?). I don't think MAF is oiled. It's MAP.