My M20 developed some issues recently.
This past weekend I did the timing belt, tensioner, water pump, thermostat, ignition rotor, spark plugs and a valve adjustment. After putting everything together, the car wouldn't start so I figured the timing was off. Took it back apart, reset everything and it turned over and ran. It ran a little rough but I was exhausted and closed it up.
Today I got it back together completely and now I've got a few problems:
- Rough idle when cold. It acts like a vacuum leak but I couldn't find one and after a quick drive around the block it was idling fine. I listened to the injectors and they are surging with the idle when this happens.
- Stuttering/surging when driving. At low speeds (20-45) the car bucks a little when driving. It's not extremely pronounced but can be felt in the seats and on the steering wheel. This can be replicated every time. At higher speeds, 50+, the car feels fine.
- Car seems to be making some noise from the bottom end but this could be my bad throwout bearing which knocks when the clutch is engaged.
So far I've:
- Checked for vacuum leaks
- Reset the spark plugs
- Checked the valves again (have a good sewing machine tick)
- Put a screwdriver up the oil pan and heard some grinding after a strange noise coming from the front end after the test drive. I don't know if I've got a bad bearing or I'm just paranoid after all this. (My throwout bearing does knock when the clutch is engaged but I had a buddy press the clutch and the noise was still present. )
Not sure if a bearing is correlated to these other issues. I'll pull the spark plugs one by one tomorrow to see if that takes care of the noise.
Thoughts or further diagnostic tests? My next step is plug test then either pull the pan to check the bearings or start pricing out an M50 swap.
This past weekend I did the timing belt, tensioner, water pump, thermostat, ignition rotor, spark plugs and a valve adjustment. After putting everything together, the car wouldn't start so I figured the timing was off. Took it back apart, reset everything and it turned over and ran. It ran a little rough but I was exhausted and closed it up.
Today I got it back together completely and now I've got a few problems:
- Rough idle when cold. It acts like a vacuum leak but I couldn't find one and after a quick drive around the block it was idling fine. I listened to the injectors and they are surging with the idle when this happens.
- Stuttering/surging when driving. At low speeds (20-45) the car bucks a little when driving. It's not extremely pronounced but can be felt in the seats and on the steering wheel. This can be replicated every time. At higher speeds, 50+, the car feels fine.
- Car seems to be making some noise from the bottom end but this could be my bad throwout bearing which knocks when the clutch is engaged.
So far I've:
- Checked for vacuum leaks
- Reset the spark plugs
- Checked the valves again (have a good sewing machine tick)
- Put a screwdriver up the oil pan and heard some grinding after a strange noise coming from the front end after the test drive. I don't know if I've got a bad bearing or I'm just paranoid after all this. (My throwout bearing does knock when the clutch is engaged but I had a buddy press the clutch and the noise was still present. )
Not sure if a bearing is correlated to these other issues. I'll pull the spark plugs one by one tomorrow to see if that takes care of the noise.
Thoughts or further diagnostic tests? My next step is plug test then either pull the pan to check the bearings or start pricing out an M50 swap.
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