V-8 growling under load only after warm

[Mattbram]

Hi Folks,

I couldn't seem to find another post that matched my symptoms. I have a 2002 Explorer with V-8 engine. On a cold crank, it sounds as good as it did the day I bought it…for about 3-4 miles. Then, under load, I hear a growling noise coming from the engine on the driver's side. This happens just when I accelerate and put the engine under load. It does not occur when revving in neutral or park. It does occur when revving in drive with one foot on the brake. Again, for those first 3-4 miles when it's cold, I can gun it as much as I like and never get the noise.

This first occurred a month or so after replacing the transmission with a remanufactured unit. Since it was under warranty, the mechanic replaced that unit. No change in the noise. Maybe the timing of the noise was just a coincidence.

Any suggestions on where to look? Could this be an exhaust manifold leaking after it heats up.

Many thanks.

 

[Green98XLT]

I know this is old, but did you ever find your problem? I'm hearing it in mine and told its the torque converter clutch plates that causes it. My growl goes away when the converter locks so I'm certain thats the cause...

 

[Mattbram]

Mine still makes the noise. The Ford dealer wanted to replace two cracked motor mounts before they could diagnose further ($900). I know that's unrelated so it didn't make any sense to replace mounts on a car with nearly 300K miles on it. Mine does not make the noise in neutral…only under load, so it sounds like a different problem than yours. Now I'm thinking main bearings so we'll drive it until it quits.

 

[Joe in NY]

Umm. If your motor mounts are shagged under load they will not hold your motor where it should be and allows thing to rub that shouldn't rub and also transmits far more noise through out the car than good mounts...

 

[Mattbram]

I'm not a mechanic, but my regular mechanic was very skeptical that it could be the mounts. If it were the mounts, why would the noise not be present until the engine gets hot? Any ideas?