Dear fellow members and experts,
I bought this car C180 2002 model a bit more than one year ago. After one week it started misfiring on cylinder 3 with error code P303. i took it to garage and they changed spark plugs and cylinder 3 coil. It didnt work and check engine light came back again. They did compression test and cylinder 3 was low on compression, so had to pay almost 2000 pounds to get it fixed by scratching the cylinder head and putting new valves etc... After that up until now Car has been running perfectly.
From last one month i noticed that it is consuming more fuel. I thought its probably because Service A was due in 500 miles. Then 2 weeks ago i was driving to work and check engine light came on. I parked car at work and after almost one hour check engine light went off automatically. Next day when i was driving at work, i got a message displaying that top off engine oil 1 Litre, and it disappeard after a while. I topped off engine oil next day with the right brand after asking dealer.
Car wasnt running smoothly from last few days, the day i topped up engine oil, check engine light was on already.
It was evening and all garages were closed so i rang breakdown services and they checked it on their computer and told me its P303 misfire on cylinder 3. God i was really worried that the compression problem is back.
They guy from breakdown service told me to change coil 3 and see what happens. He cleared the error and it didnt come back for another 2 days. I was too busy at work that couldnt get time to buy new coil for another 2 days. Check engine light didnt come back again for another 2 days. Next day it happened again and check engine light came back .I bought new coil next day and replaced the old one and put super unleaded fuel . After this coil the problem became even worst. Car was stopping every traffic light. As soon as it becomes idle at traffic lights it start shaking badly. After turning off engine and turning back on again it runs fine for another few minutes.
I took it to another mechanic and he told me to change spark plug and replace the new coil with another one because the coil i bought could be faulty. So i went and replaced this coil, bought 4 spark plugs and went to the mechanic to get them installed. He check and spark plugs were in bad condition. Specially number 3. After replacing spark plugs and installing new coil, car became smooth and i was so happy that i didnt had to pay a fortune again to get it fixed.
After 2 days (i didnt drive much on weekend)...Yesterday while i was driving to gym car started shaking again on traffic lights and i had to turn off engine and turn it back on again.
Could anyone advise what could be the reason, i will take it to garage again for a compression test (i am scared if the problem is back again).
Is it possible that cylinder will lose compression again while i drove almost 10000 miles after getting the cylinder head fixed.
Why car became smooth for 2 days after changing spark plugs and cylinder 3 coil and problem is back on again.
Please explain .. here i am explaining how car behaves ..
when i turn on cold engine, i can feel a minor vibration on steering wheel.
After 15 to 20 mins of driving when engine is hot it starts misfiring at traffic lights and i have to turn off engine and turn it back on again. Check engine light is off now and doesnt come back again.it should come back when misfiring but God knows whats happening.
I appreciate your help in advance.
regards,