Mechanics

WHAT IS THE CAUSE FOR THIS VIBRATION WHICH ONLY HAPPENS OCCASIONALLY AND USUALLY AT AROUND 50 KM/H AND 80KM/H ONLY FOR 2L 4 CYL?

1999 Toyota Camry • 160 miles

Vibration at 60 - 80km/h. More noticeable when on load like going up hill. When accelerate hard the vibration goes away. Only happen when gently accelerate and when reach speed around 60 - 80 km/h the vibration comes on. Letting go the accelerator the vibration goes away. Vibration only occurs when fuel is applies by pressing on the accelerator. Spent over $500 for mechanic to replaced Pletinum spark plugs and plug cords plus tuning done at certified Toyota service center but the vibration problem still exist. What is next? Wanting to know the exact cause to this problem. Pease advice.
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John woo
January 17, 2012.




Check for loose or worn suspension components. Have the wheels and tyres balanced on the car. Check for vacuum leaks.

Rivermikerat
Jan 17, 2012.
Wheel and Tyres were balanced. If it is balancing issues or something loose it should vibrate at all time and not only when putting fuel on the accelerator right? Can it be the catalytic converter? I took the car to the exhaust place and they inspected and certified all OK and said something wrong with the car engine. I am very lost here, can't be engine? If its engine I can hear the vibration even when the car is stationary but its not that case.
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Tiny
John woo
Jan 17, 2012.
Not necessarily. It could be harmonics. Do you hear or feel a vibration with the transmission in Neutral and the car stopped while increasing the engine speed? How about while driving, throw the transmission into neutral and give it throttle.

It's a very outside chance that it could be the catalytic converter.

Rivermikerat
Jan 17, 2012.
No vibration on neutral and while increasing engine speed. When going down hill no vibration, except when there is loading such as going up hill vibration kicks in when speed get up to at times 40km/h however put more pressure on the accelerator the vibration goes away. It only happens when loading on the car and fuel is apply. Can it be the automatic transmission problem? Would it give this kind of problem if its the automatic clutch pad worn or something like that?

Tiny
John woo
Jan 17, 2012.
It could be transmission, torque converter, or engine related. But, from your description in the last post, I would lean more towards a transmission issue.

Rivermikerat
Jan 17, 2012.
Thanks. I shall give a go to have the automatic transmission a full service. Hope this fixes the problem. Shall keep you posted after this is done!

Tiny
John woo
Jan 17, 2012.
Ok. Good luck. Tell your friends about us and do keep us posted.

Rivermikerat
Jan 17, 2012.
The problem is caused by a missing bolt at the exhaust manifold. Nothing to do with the automatic transmission. Dissappointed with the exhaust place that did not pick up the problem during inspection. Maybe exhaust place only check the exhaust section underneath the car and not all the entire exhaust system all the way up to the engine manifold. Hope this helps those who have similar problem.

Tiny
John woo
Jan 18, 2012.
That loose or missing bolt must have been on a mount or flange. The manifold has at least 5 bolts securing it to the cylinder head. One loose or missing bolt in the manifold wouldn't cause a noise, except an exhaust leak. Did they replace the gasket, I hope?

Rivermikerat
Jan 18, 2012.
Apparently just that one missing bolt caused the problem.

Tiny
John woo
Jan 18, 2012.

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