Hello everyone! Yesterday morning I started my car and a few seconds later, the engine started running strangely. It vibrates, runs hard. I stopped the engine and started it again: everything is fine! So I go for a ride around the block and at the first stop... it starts again (except this time the check engine light comes on). I look for the error code and it's P0301. My prestone level remains unchanged. I reset the error code before making the following replacements: I changed the ignition coils and spark plugs. Unfortunately, the engine still vibrates when starting (sometimes). In traffic... it can start to sputter randomly again. If I press the gas pedal even a little, it returns to normal. After about 90 kilometers (about 56 miles), as soon as I stop and start again, when accelerating it gives a knock (seems to come from the transmission?!?) around 30kph (18mph) everything returns to normal. The check engine still hasn't turned back on despite the things I've noticed since replacing the coil packs and spark plugs. I don't really know what to look at anymore... since it seems like there are two problems at the same time: 1- the engine seems to start vibrating as soon as it goes from EV mode to combustion mode. 2- When I start accelerating, it gives a knock up to about 30kph (18mph) If anyone has any ideas... what to check... (Prestone level is good, no prestone found in the oil). Thanks in advance!
Code P0301 indicates problems in the first cylinder. Have you inspected the spark plugs, checked the coils? It may also be a problem with a broken head gasket, when the coolant enters the cylinder drop by drop. You can inspect with an endoscope on a cold engine for drops on the cylinder walls.
