Hello, my car is a Peugeot 206 1.4 Gasoline-LPG (2003) and it has covered 213,000 km. I bought it at 210,000 km and have had it serviced diligently as new. Timing belt sets, oil maintenance, everything has been done in short. My car started experiencing high vibrations a few weeks ago. Even though I had just started it, the car was shaking even when I did stop-and-go traffic. I didn't mind it because I didn't notice any difference in traction or engine operation. Since I bought the car, it rarely stalls while driving on LPG, even when full of gas. I have been using gasoline thinking that I will have it checked when I have the money. The car's engine is not too loud, especially on side streets, since the sound bounces, it's not rattling, but I don't think it should be like that. In addition to this information, I took my car to a mechanic and had it connected to a device because the fault warning light started while driving this week. The faults were indicating problems such as spark plugs and coils and air conditioning. Our mechanic stated that the vibration was caused by the spark plugs and replaced all the spark plugs with Bosch brands. The vibration didn't improve after the replacement, and 3 days later, the yellow light came on again while driving. The vehicle has neither poor traction nor smoke from the exhaust. When I looked at vehicles with misfires on YouTube, I saw that it had nothing to do with the noise they were making, so I can't say there is a misfire. In short, there is no problem other than a tangible vibration in the vehicle, and the yellow light is on. Our mechanic said that if the problem persists, the valves need to be adjusted, and he stated that both the malfunction light and the vibration could be causing it. Believe me, I can't tell the mechanic to do whatever is necessary due to financial difficulties. I appreciate your valuable opinions. Some say a blown gasket, others say the engine is dead, but other than the vibration, there are no problems. When we picked up the vehicle, the expert came up with a 92 engine, saying there was a noise in the engine and minor oil leaks. I've read hundreds of posts; some have tried the throttle body, some the idle motor, and others the valve adjustment, but most of them continue to have the same problem.