2006 Scion Tc base automatic transmission, has 149k miles on it.The car used to vibrate a little at idle. It suddenly started vibrating a lot. It is shaking as if there's an earthquake!

Idle rpm at parking and neutral is close to 1k. Idle vibration goes severe on D and R, at 600-700 rpm. Also, bad smell is coming from exhaust after a while, more like sulfur. The car is shaking so hard that I am not driving it over 25 mph. It is not accelerating either.

Looking for some expert advise. What is exactly wrong with the car?

  • 1
    Sulfur smell has me leaning towards bad / plugged cat. Any Codes?
    – rpmerf
    Dec 7 '15 at 12:39
  • @sh-k were able to validate any of the suggestions related to your catalytic converter? Dec 9 '15 at 7:26

A catalytic converter is designed to increase the temperature of the exhaust to convert hydrogen sulfide to sulfur dioxide.

The reason you are smelling sulfur in your exhaust is one of two things.

  1. The titanium within the cat has been used up or burned off over time. Since the dense titanium is not retaining heat any longer the steel or other material it is bonded too is getting coated with carbon and insulating the internals of the cat and thus preventing it from getting to the temperature it needs to be at to complete the conversion process from hydrogen sulfide to sulfur dioxide. Thus the scent of sulfur.

  2. The cat is actually clogged and preventing the exhaust from escaping in the normal freer flowing manner. The restriction in the exhaust causes too much back pressure and is effecting the combustion process in the engine and giving you performance related symptoms.

You may receive engine codes and have a check engine light on.

You can go to a local car parts store and many of them will connect an ODBII tester to your vehicle to get the error codes that can tell you what components you need to replace.

Cat converters can be expensive due to the titanium used within them to retain heat in order to convert the hydrogen sulfide to sulfur dioxide.

Best of luck

  • Sorry for the late reply, was busy with something else. Meanwhile I tried to change the spark plug, and noticed there is oil around the spark plug and coils. So I am thinking of changing the valve cover gasket first. What do you think?
    – sh-k
    Dec 18 '15 at 21:19
  • I made another mistake. While changing the spark plugs, I didn't notice the oil for the first spark plug until I removed it. So oil must have got into the combustion chamber for that spark plug. Do you have any Idea how to remove the oil from inside the combustion chamber when I change the gasket? Also, how does the leak and the symptoms (vibration, smelly exhaust) co-relate?
    – sh-k
    Dec 18 '15 at 21:25
  • When you have clogged catalytic converters it restricts the exhaust gasses from escaping the engine. This makes the engine run poorly. As well, catalytic converters can get clogged because of a poorly running engine. If the mixture from the fuel injection is too rich carbon can buildup on the surface of the catalyst metals within the converter. If you are burning oil that can also coat the surface. Sometimes running the vehicle hard on the freeway for an extended period of time can burn these contaminants off and make the car run better. Dec 18 '15 at 22:15

sounds to me like a bad cat/cats. I would check those. they were clogged on my blazer and it wouldn't like me drive fast and it smelled awful inside the car

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