Never use so-called engine cleaner to clean. I was cheated by 4S half a month ago, and I regret it very much. After cleaning, I feel that the internal lubrication of the engine is poor, the friction resistance is greatly increased, the noise is too loud, and the fuel consumption is soaring. I have to keep stepping on the gas pedal to move, and the speed of sending the gas pedal decreases rapidly. It should have washed away the oil film attached to the internal parts, causing the parts to rub directly, so the engine can't afford to be injured. It is said that it may also lead to oil seal hardening and oil leakage. Damn it, 4S, in order to completely remove the residual detergent, I replaced the new oil I just added in just two days. Now the vehicle feels injured, with great resistance and noise. Cheyou remember not to be fooled by 4 S.