Back in February I was driving on the highway and it made a backfire when downshifting or accelerating quickly. We had a pretty cold winter in Wisconsin this year so I thought maybe that was the issues. But it started to backfire more and rough idle and such.

This was coming back from my 200 mile drive to drill. Which until that moment had done fine 5 other times.

It didnt really back fire unless the engine was cold. Then it would do a machine gun sounding backfire from the exhaust. Which is probably because the PO poorly fixed a hole in the exhaust. Either way at different RPMS or when it was warm the backfire was more at idle then while driving.

My other vehicle also broke down on me. Mind you i parked my car in March. I started it today. IT started just fine. Same rough idle. And really no backfire until you let off the gas. Took it to 4K RPMS without any issues.

But the rough idle shakes the engine. It also shakes the car. But as I said. Once you rev it a bit the backfire/rough idle is gone.

So what can cause this problem? Is it a sensor/valve/whatever? Or is the head gasket blown?

 

Put a bottle of injection cleaner in the tank. Could be a clogged injector. Start with the basics. Plugs, wires, rotor, and distributor cap. Not enough info to pinpoint the problem.

 

Seafoamed. Did wires and spark plugs and its back up and running. Thanks

 

Thanks for letting us know what you did. It always helps other members who have a similar problem.