Cadillac Seville STS Rough Idle

Learn if it's a simple fix or time to seek out a trusted technician.

What are common reasons my Cadillac Seville STS has a rough idle?

While there are a variety of reasons your Cadillac Seville STS has a rough idle, the most common 3 are a vacuum leak, an issue with the spark plugs, or a problem with the ignition coil.
of the time it's
Vacuum Leak
of the time it's
Spark Plugs
of the time it's
Ignition Coil

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Related Cadillac Seville STS Questions

See what others are asking about their Cadillac Seville STS. Get answers from RepairPal's community of auto experts and enthusiasts.
I have a 99 sts with a rough idle and hi pitch whistle under the hood. anyone have the same issue, i know its a manif...
Dealer said i need new spark plug wires but they were replaced about 15k miles ago

Related Cadillac Seville STS Problems

Find the most common driver-reported problems that are to blame when a Cadillac Seville STS has a rough idle.
The egr control solenoid or egr valve may fail causing the check engine light to illuminate.
The egr valve may stick open, causing a rough idle and/or the check engine light to illuminate.

Cadillac Seville STS Rough Idle Repair Symptoms

A failing ignition coil will create misfires in the engine, and lead to hesitation, extreme power loss, engine stalling, poor fuel mileage, and illumination of the check engine ...Read More
As we discussed, spark plugs are necessary for any gasoline engine to run. When they fail, the engine is in a constant state of attempting to ignite air and fuel, but cannot. Th...Read More