Mechanics

CAR SHAKES WHEN ACCELERATE OR BACK UP

1999 Toyota Camry

Engine Performance problem
1999 Toyota Camry 4 cyl Two Wheel Drive Automatic 160000 miles

The car recently started shaking when speeding up. The shaking is more sever when backing the car out of parking lot. When speeding up from a stop light, it is difficult to pick up speed. However, if I release the gas pedal and then push it again, it may work just fine. Also, I sense some lost of power when going up hill. The car runs better when engine is warm but may still shake when go from low speed to higher speed. Usually when speed is over 40, it seems everything working fine. I put in a bottle of fuel injector cleaner and it seems helping a little bit. However the engine check lights up right after adding the cleaner. Seek your advice on what really goes wrong. Thanks.
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Bhqiao
February 1, 2009.




Hi bhqiao,

Thank you for the donation.

The symptoms decribed seems to point to a misfiring and it could be due to faulty spark plugs or related parts. Check them out.

As the CEL is showing, you should get a scan done to retrieve the Diagnostic Trouble Code (DTC) to find out what is causing it and it should be related to the misfiring. You can get a free scan done at your local Autozone outlet and get back with the exact DTC so we can proceed with rectification.

KHLow2008
Feb 1, 2009.
I replaced all 4 spark plug. One of the old plug looks oily. The new one makes the car run smoothly for 2 days and the same shaking problem came back. I took the newly changed spark plug out. It looks oily near screw too. One Pepboy assistance said there is oil leaking. How do I go from this point now? Thanks.
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Tiny
Bhqiao
Feb 7, 2009.
Is the spark plug wire oily at its end near where the spark is attached? If it is, the leak is external and would cause the misfiring due to sparks jumping when oil accumulates.
Did you clean the oil off?
The leak would be caused by the plug tube seal. However the leak from this area is usually not much and should take quite some time to accumulate. Cleaning up the oil with the aid os compersed air and a piece of rag attached to the end of a long screwdriver should work, at least till the oil accumulates.
Check if the spark plug wire for that particular cylinder is bad with a resistance test. There must be continuity with a resistance value of below 25 k ohms. The oil could have damaged the wire.

If oil is only on tip of spark plug, it would be internal and would cause oil burning which would emit grey smoke when engine is idling. This would foul up the plugs and cause misfiring. You did not mention any smoke so should not be this problem.

Did you retrieve the DTC?

KHLow2008
Feb 7, 2009.

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