Intermittent Slight Misfire

[crash0ride]

I have a intermittent slight misfire on an 08 Tahoe LT Flex-Fuel

I feel a shake like a little miss or something when at a stop in drive or park sometimes. 40K Any ideas and is this covered under the powertrain warranty?

 

[stevek]

You sure it's not preignition?

 

[crash0ride]

You sure it's not preignition?

I dunno, feels like a rough idle, mild miss to me at random times. Doubt it would be preignition since the vehicle wasn't running for awhile and after 5min of running it was doing it.

 

[OklabyGodhoma]

Put 2 cans of Chemtool B12 in a FULL tank and run it until almost empty. Do not change the type or octane of the fuel you normally use. It will clean your whole combustion/fuel delivery system as well as cleaning your valves. Let us know if things clear up....I think you will be suprised.

I run a can as preventative maintenance about every 10 tankfulls. Keeps out moisture, and keeps things clean inside. The reason for two cans is because of the size of our fuel tanks and because it hasn't been done before.

 

[crash0ride]

I've usually used BG 44K in my vehicles. I just picked up this Tahoe so who knows if crap gas is in it.

 

[GreatWhite]

If it really is a misfire there will be a diagnostic code on it. Scanners are cheap enough that you probably know someone who has one or can can talk someone into doing it for free. If it is throwing a code it would be covered by the emissions warranty (that's why the feds mandated that it be flagged). If there is no code there is a good chance you are feeling something else like stick/slip in a driveshaft yoke.

 

[GM Customer Service]

I have a intermittent slight misfire on an 08 Tahoe LT Flex-Fuel

I feel a shake like a little miss or something when at a stop in drive or park sometimes. 40K Any ideas and is this covered under the powertrain warranty?

Hello,

Sorry to hear that you are having problems with this. It is possible something like this could be covered. However, the only way to really say for sure is to have it diagnosed. If you need any help with anything, please let me know.

Geoff Allen
GM Customer Service

 

[BigRed76]

check your plugs ..... sometimes its the simple fix that we don't think of doing