I don't think so, I give my car to danish motor every 5k, they never wash it with oil or petrol, engine bay is as clean as new after doing the service, I have never find them out of car, full jam packed every time. It is very hard to clean engine bay without sufficient pressure, with all gutter bloating and dust, you cannot keep engine bay dirty for long otherwise it will eat-up wiring. I only get engine bay clean after 5k, so far it is working out well work me!