Buzzing Noise

[BryanGrigsby]

I have a 98 240. When there is no load on the engine it buzzes, especially as the RPM's are falling. I'm guessing it is something in the head, the lifters or the valves? How do I fix it depending on what it is?

[BryanGrigsby]

OK. I'm pretty sure it is a valve problem. When I jump on the throttle it also buzzes at me pretty hard. There are also certain rpm's at which the buzzing seems to be more intense. Maybe I just through off the timing? I drove for about an hour yesterday at about 80mph at about 3400 rpm's. Im guessing it did some damage? Any way it deffinitely is a noticable change. I wonder if I could've done any damage to the block, pistons, rings, rods or crank?

[BryanGrigsby]

Well I think I put in some bad gas. Filled it up with some 89 octane the other day at a truck stop. It dawned on me that who the heck puts mid-grade in their car. The gas may have been sitting there for who knows how long. The noise is still there but maybe after this tank it will go away.

[BryanGrigsby]

It was the stupid heat shield on the exhaust after the Cat. So I cut it off.

[HashiriyaS14]

It was the stupid heat shield on the exhaust after the Cat. So I cut it off.

I've got a '98 5spd, and I've got exactly the same buzzing noise. Are there any negative consequences of removing this heat shield? The buzzing is really getting on my nerves, and I was worried that it might be something more serious.

Has anyone else had this problem and/or used this solution?

[BryanGrigsby]

I wouldn't think that there would be any adverse effects related to it other than its annoying and aggrevating. That is as long as you know it is you heat shield. Mine was half rusted anyways, as is the case with most stock exaust peices.

Took a little effort and alot of dremel circular cutting discs, but I annilated it.