Hi,

My wife has a 99 E/B Expedition 4x4. When you take off with a little more than quater throttle there is a roaring sound coming from the engine when the motor gets around 2k rpm. It goes away after about 500 rpm. Its pretty loud in the cabin. If you take off normally it doesn't make that sound. Anyone experience this???

Thanks!
Roland

 

With an AF1 (or any FIPK), if you're really getting on it, it's the throttle body opening up you can here. Does it soulds like the old days of flipping the lid on a 4bbl carb? If so, enjoy it.

If it's really hot, it's probably the fan. Mine sounds like a tractor with a loaded 60' trailer taking off for a little bit if it's really hot. The fan is doing it's job sucking a lot of air to cool it down. I'm guessing it's the air intake and it's normal. You can't hear it with a stock air box.

 

Unfortunately the AF1 is on my truck... The expy still has the stock intake.

 

It definitely sounds like the fan. How hot is it anyway? Does it roar all the time? Typically, it should roar just a little right when you first start it. Then it should quiet way down seconds later. If the engine is still cool and it's still roaring, then something is probably wrong with the fan's clutch. It might be defective.

 

I can hear it when you take off moderately fast. If you ease into the throttle it's alright. I was thinking maybe it was the heatshields or something. Or, maybe it's just the restrictive intake???

Thanks for all your replys!
Roland

 

Yep, that sounds like the fan with what you'r describing. Mine does it sometimes too. Once you get moving and it cools down, the next start is usually quieter as long as you weren't sitting there in heat again. Does that sound like it?