pmthk

hi everyone

i have a 2008 is350 and i switched to mobil 1 synthetic oil since my last oil change. i took the car for the valve spring recall and as i was driving back home, noticed that my engine was not running smoothly as before. my question is does the valve spring replacement work entail change of motor oil? if that was so, i think they replaced the engine oil with conventional oil. the dealer should have asked me if i had synthetic oil because i heard that once you go synthetic, you can't go back to conventional. if that was the case, what's the extent of the damage that may have caused to my engine. what should i do next? i'd really appriciate your advice.

sincerely,
pmthk

llamaboiz

dont know about the recall info but this part of your story is untrue, you can switch from dino to synth to dino to synth to dino~ anytime you like. the person you 'heard' this from i suggest you dont take his/hers advise anymore.

Kurtz

iTrader: (1)

Yup... in fact they're so compatible with each other they even sell them pre-mixed together. It's called a synthetic blend.

Mind you, you lose most of the extra benefits of running synthetic by mixing, but it doesn't "hurt" anything.

onepointon

That is not the cause. What type of noise is it making?

If the car is not running as it was before, you should take it back to the dealer and let them check it out.