Q: my car has a rough start

asked by on

When the engine is cold, it has a rough start and feels like it's gonna stall out, it also blows out black smoke, I recently changed the spark plugs, oil and air filter. I took out one of the spark plugs and 1st, 2nd and 3rd where lightly covered in oil, the 4th one was just fine. What could be the issue?

If the spark plugs are coated in oil, that can cause a rough cold start or idle. The engine is burning oil in cylinders 1, 2, and 3. The most typical cause is from worn valve guides. The intake and exhaust valves move up and down within the valve guides. When they wear, oil can get past the valve stems, coating the spark plugs. Other causes can be worn piston rings and/or scored cylinder walls. A complete compression test should be done to determine which is the cause. Worn valve guides can be remedied by rebuilding/replacing the cylinder head. Worn piston rings or scored cylinder walls may require an engine rebuild/replacement. Have a trained technician inspect the starting issue in order have the right repairs made.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. my car has a rough start

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: I hear a rattling noise when my truck is parked. But when I drive it the noise stops. It sounds like a metal ball is rattling around.

Often, some exhaust components like heat shields or hangers may rust or become loose and rattle over time and is pretty common for the type of sound you're describing. If you are not experiencing any drivability concerns, the rattle may...

Q: Q: Is this the alternator or just the battery?

Since the battery was dead, this could be the cause of a failed alternator that was unable to maintain the battery charge. Try charging the battery first and running the vehicle. If the Charge Warning Light illuminates, there could be...

Q: There is water in my gas tank - 2004 Nissan Sentra

If you think you have water in your fuel, then you would have one of two problems. You would have a misfire and a rough running engine if there is some water in the fuel but not enough to keep...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...