Engin surge at idle

[wholmes98]

My 98 C5 has just started a slight engine surge when idling and when slowing down approaching stop lights, etc, A very slight increase followed by decrease in rpm. Engine runs fine otherwise. Does this sound like a throttle position sensor problem? Any advise appreciated. Thanks.

 

[LLC5]

My 98 C5 has just started a slight engine surge when idling and when slowing down approaching stop lights, etc, A very slight increase followed by decrease in rpm. Engine runs fine otherwise. Does this sound like a throttle position sensor problem? Any advise appreciated. Thanks.

Not really, that will usually set a code and turn on the CEL. Check your DIC for any stored codes. It could be false air (vacuum leak) entering the intake. Common areas are the pcv hose by the right valve cover, also check for any rodent damage in the engine bay, even if garaged.

 

[Otter]

Not really, that will usually set a code and turn on the CEL. Check your DIC for any stored codes. It could be false air (vacuum leak) entering the intake. Common areas are the pcv hose by the right valve cover, also check for any rodent damage in the engine bay, even if garaged.

Had that with the PCV hose coming from the right valve cover on my 99. Good advice.