Infernal combustion question

N:dlzc D:aol T:com (dlzc) · 2008-03-07T02:46:26+00:00

I have a 2004 Chevy Cobalt (aka. Cavalier). When new, I was getting 30.5 mpg or so. Then about 45,000 miles the valves started to burn. Replaced the heads under warranty, and the mileage has dropped to about 25.5 mpg... with the same lead foot in the same kind of traffic.I understand that running lean will make the valves hotter.But this thing has no guts (not that it had much before), and I really miss the extra mileage.The dealership says that it is set for factory settings...Ideas?David A. Smith

Mar 07, 2008 20 Replies

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dlzc 18 years ago

On Mar 9, 10:08=A0am, "N:dlzc D:aol T:com \(dlzc\)" wrote: =2E..

Diagnosis: a damned air filter. Mileage climbed from low 25's to 28 and still going up.

Absolutely stupid. Sorry for all the "storm". When I actually did oil changes myself, I'd replace the stupid thing every other oil change. But if it is not a schedule published by GM, it does not get done. Depending on the dealer.

David A. Smith

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