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I have a 97 Pontiac sunfire It shakes when you make it to speeds of 70 and greater and your check engine light has come on Could the check engine light be related to the shaking?

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2013-09-04 14:22:36

Answer BEFOR YOU SPEND ANY MONEY ROTATE THE TIRES FRONT TO BACK

THIS WILL LET YOU KNOW IF ITS TIRES/RIMS BENT

Sounds like you need your rotors checked. Warped rotors are usually

caused by high speeds with fast stops.

fast stops not mentioned?

Depends what is shaking, if it is the motor, it may be a misfire

and would set the check engine light. Tire balance is typical of a

high speed shake but is unrelated to the check engine light. These

are my thoughts on check engine light:

The " check engine light" is by far one of the most

misunderstood technological advances It is a warning light that is

illuminated when there is a problem affecting the EMISSIONS of the

vehicle.. Don't let it bother you as it is a good thing once you

understand it. One point that was brought up a recent meeting of

technicians was that the amount of hydrocarbons is greater when the

gas cap is left off than when the engine is running. Hydrocarbons

are part of pollution emitted as gasoline evaporates. Going a step

farther, one facet of the emission system is the "Evaporative"

portion. This is when the fumes from the gasoline are leaking from

the system into the outside air. This is one part of the emission

system that can trigger a check engine light. I would say a small

percentage of the vehicles that have a check engine light are the

result of a loose or inadequate gas cap. But understand that many

scenarios are possible with the "check engine light" The vehicle's

powertrain computer (note that some vehicles have multiple

computers aside from the powertain computer) will run a series of

self-tests. They will only run under certain criteria. And they are

different from manufacturer to manufacturer. Some self-tests or

�monitors� are not run until preceding ones have run successfully.

So if there is a problem in one particular area that is preventing

another self test from running, you can have a situation where one

problem is fixed, but another still exists. If you fix a problem

and drive the car through a drive cycle that sets the monitor (or

self test) the light will go off as it passes that criteria that

triggered it in the first place. There are many different sources

for the light to come on. Anything that caused combustion to fail,

commonly called a misfire will set the light. Various sensors such

as oxygen sensors that evaluate the exhaust before and after the

gases are burned in the converter. Transmission codes may set the

check engine light to appear. If the car is running okay, get it

fixed in a reasonable amount of time such as within the month. It

will probably save you fuel if you do. However if the Check engine

light is flashing, you should be driving it as damage is being done

to the converter. Some emission components are covered beyond the

standard warranty. The converter for example is covered up to

80,000 miles by the manufacturer. After 1996, the auto industry

went to a idea called OBD II (on board diagnostics). This was to

get all the manufacturers onto a similar plane for troubleshooting

and powertrain control. While they still differ, many corrections

and adaptations were made for technicians to better fix the check

engine light problems. Prior to this there were so many different

and poor troubleshooting data from a check engine light problem

that resolving the problem was much more difficult. Many early

warning light of this nature were set to illuminate based on

mileage. An Oxygen sensor was one of the things that were meant to

be replaced when that mileage was hit. This is much like many

current "Change oil lights� that are set based on a pre-set

mileage. To start testing for the check engine light, you�ll need

to find the codes from the computer, match the code to the

troubleshooting procedure, follow the procedure to find the source.

Repair the source, light will go out if that was the only problem.

There are "monitors" or self tests the computer runs the car

through a drive cycle, if a problem occurs, it may not run all of

the self tests until that problem is taken care. There are

self-tests for the oxygen sensor circuit, egr system, evaporative

system to name a few. Therefore, another problem may exist. It is

emission related.

OR hook up a scanner that is capable of clearing codes, and hope

that it won�t come back on. But don�t bet on it. Lastly,

disconnecting the battery in some cars will clear the memory of the

computer and may temporarily turn the light off. Beware that this

may also cause other problems such as the car not rembering it�s

idle and will have to relearn it, the radio may be rendered

inoperative or in the case of the new Toyotas, the air bag can

blow........

SHANNON..{LET ME CORRECT THE PREVIOUS POST, It is A fact THE AIR

BAG WILL NOT BLOW WHEN CHANGING THE BATTERY IT IS a required

manufactured safety feature of the system - so that airbags are not

deployed when the ignition is switched off. IF THE CAR WAS WREAKED

AND THE SENSORS WERNT CHANGED THEN U RUN A RISK, ON YOUR SUNFIRE

THE GASCAP DOES NOT SET OFF THE CHECK ENGINE LIGHT, TAKE YOUR CAR

TO AUTOZONE OR ADVANCE AND THEY WILL PULL THE ENGINE CODE FOR FREE

FOR YOU.AND SAVE YOURSELF TIME. ALSO A KNOT ON A TIRE CAUSES

CERTAIN SPEED VIBRATIONS AS CAN MISALIGNMENT, TO CHECK FOR KNOTS

JACK UP THE TIRE AND SPIN IT LOOK FOR OUT OF ROUNDNESS, IT TAKES

YOUR CAR 15 MILES TO RELEARN ANYTHING IT NEEDS FROM DISCONNECTING

THE BATTERY}...SHANNON


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