Skip the auto shop - Our mechanics make house calls

Q: Fuel system issues - blue smoke this morning, check engine light on & off, engine vibration

asked by on

A few weeks ago, I had to have my car towed in because it wouldn't start & there was a strong gas smell. The garage said the fuel line had come undone, but they couldn't figure out why; only guess was "soft motor mounts." After I got it back, I noticed the engine vibrating/shaking when I start it, then it evens out after the car warms up. Had some start-up issues; got a new battery, but still has some starting issues especially in early, cold morning.The check engine light started flashing on startup, along w/engine shaking, then the shaking would subside & the light may stay on or may go off. This morning, it gave one quick turn-over (1 second), acted like it didn't want to start, then started up and ran ok, though vibrating some & with blue smoke - a lot at first, then subsided some except when accelerating. Never had any of this prior to fuel line coming undone. I'm wondering if there's a fuel line/filter issue? Puzzled, because the car's run smoothly prior to this.

My car has 103000 miles.
My car has an automatic transmission.

Hello. Thank you for writing in. It sounds like you may be dealing with more than one issue. The first thing we should discuss is the blue smoke coming from the exhaust. This typically means that the engine is burning oil. Burning oil can be caused by worn piston rings, worn valve seals, PCV malfunction, engine oil seals, and bad head gaskets. This would cause the engine to run poorly, misfire, shake, and would also soil the spark plugs causing another set of issues. You should look into finding the cause of the oil leak, and fixing that first. Keep in mind the vehicle needs more fuel when it is cold and that may be why you smell fuel when starting. Its because the engine is running very "rich" until it warms up. This may also be playing a factor. Start by tracing down the oil leak, and making the appropriate repairs.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!
  • Home
  • Questions
  • Fuel system issues - blue smoke this morning, check engine light on & off, engine vibration

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: Car does not accelerate when pressing gas pedal, 2002 Suzuki Vitara

Hello there. This is a usual issue for a 2002 Suzuki Vitara. There are a few possible causes for the lack of power and engine surging. The most likely would be the throttle plate, throttle cable, MAF sensor, vacuum leak,...

Q: Battery indicator light coming on

The charging indicator light comes on when your vehicle is not charging or you have an ignition cylinder binding and not coming to the full run position. The ignition switch and key lock cylinder may be at fault. The rough...

Q: Cruise control broken

Hi. Cruise control systems only engage past about 35 mph, so make sure that is not the issue. Other issues that can sometimes interfere with the cruise control are brake lights that may be having connection issues. The system uses...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
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...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...