Hi all,

My Ranger started doing this crazy loud jackhammer noise on the freeway. The motor feels like it lost a little bit of power, and there's vibration that increases when accelerating. The sound never goes away, even when idling.

I've included a video here.



What could it be?

 

Welcome to the forums.
Sounds like a valve problem or something to do with the valve train.

I would start with a compression test.

What it sounds like to me is the piston coming up on compression and the compression is leaking through one of the intake valves.
Or possibly the exhaust _ you would hear it through the exhaust pipe though and the sound appears to be coming from the engine bay.

When was the last time a new timing belt was put in it ?

 

Hi again!

Thankfully it was a simple thing -- a spark plug had 'exploded' and had come out of the socket. The wire was half molten. I have no idea why that happened (and I didn't suspect the spark plugs at all). But after changing the plug and the wires everything sounds as smooth as always.

Thank you so much!

 

That's good it was something simple.
What brand of spark plugs are you using ?

 

Autolite Double Platinum.

 

I know the compression is quite high on the 4, but I've never heard of something like that happening either.
Maybe a defective plug ???