My high-mileage '97 Explorer Sport shudders and vibrates and makes a somewhat metallic knocking/rattling at idle. It's most noticable at startup, but if the radio and A/C are off, I can sometimes hear it at stoplights. However, it runs beautifully at all speeds with NO odd noises. All the belts are fairly new, and everything seems to be tightly buckled down under the hood. Nothing obviously loose or rattling around by causal inspection at idle, even tho I can hear the noise!

Anyway, do these symptoms sound familiar to anyone, or do any of you have any suggestions?

Thanks...

Try searcing under fan-belt tensioner, that is a common problem with this year explorers

I have noticed the same thing on my 97 XLT

Check your motor mounts??

Since you have a high mileage X- it could be due..

My explorer is starting to shake a bit when idleing. I have 165,000 Km . Is it time to replace my motor mounts?

I had this too on a 97 sport. I was in at my dealewrship last week to drop off my Firestones and they heard it and it turned out to be a recall. I believe it was the Timing Chain Tensioner