hey guys i need some help. I was driving on the highway today and i hit 70 then all of a sudden their is a loud noise coming from my engine. It sounds like a rock in a can. Anyone ever experience this. I have asked some of my friends about this and they are stumped. All of the fluids are good. PLEASE HELP!!! ANYONEwith any ideas. Thank you

 

Just poking in the wind here, but I believe a sound like that usually is what detonation or knocking, but you should get that more often than just then. More info is necessary for an actual diagnosis. Try and repeat the occurance, try at different speeds see if throttle position and engine RPM have something to do with it. Did you get bad fuel? What year/engine/miles?

 

Only in 5th gear, tried other gears at similar RPM's. Its right around 2800 - 3200 in 5th gear. Its a 4cyl engine. Standard transmission. Don't think it was bad fuel. What do you mean by that?

 

Bad fuel can do a lot of things to your car. It can make it feel like your engine is going to give out. Considering it is only occuring in that specific gear and that specific engine speed, I'd be guessing that it is a possible Trans problem. I think it would probably be more consistent if it was an engine problem (not just that gear or speed). If it was a problem with the Trans, it should be throughout the entire gear, and should not matter on the engine's speed. I can't think of anything at this time other than what I have told you. Check it again at your next gasoline fill up and go from there.

 

When you fill up also, put the highest octane in it that you can, and use mobile. It will clean out your engine as well...

 

Turned out to be nothing major, the bolts to the skid plate came off and were causing the trouble. Thanks for your help everyone.

 

glad to hear it was nothing big.

 

skid plate?? um.. bro the mazda 6 doesnt have a skid plate..

 

Um bro....yeah it does....It's the plastic shield that covers the bottom of the engine.

 

its not a skid plate that my girlfriends jeep has, but it is a plastic shield that prevents stuff from geting up inside your engine...