Dark Stone

This has just started happening in the past few days. I can hear a high pitched whine from the engine compartment when I'm either accelerating or cruising at any speed above 40mph. It isn't always there but as I'm driving along this whine will start then stop all on it's own either when I'm accelerating or just driving with the cruise on. Then it will drop off on it's own. It always goes away if I decererate. It almost sounds like radio feedback but it dosen't go away if I turn the radio off. I'm thinking a vacuum leak maybe. The only constant is I seem to need to be over 40MPH. When it first started it would only happen if I was over 70 now it's gotten worse in the past 24hrs or so. Does anybody have any idea what this could be?

John

bhale943

I have been experiencing the same problem the last three weeks. I also first thought it was stereo feedback, but no. The noise occurs for me at 40-42 mph, almost sounds like a turbo spooling...I wish. I am from wisconsin and am guessing the problem is cold related. I searched for blown vacuum lines, but none were found. Seems to be transmission related, happens warm or cold, but more often cold. I will update after I meet with my mechanic. Thanks

Mod (Ret.)

Two possibilities; either a bearing in the alternator (Ford still refers to it as a generator), or the power steering pump.

Good old Bill

Just curious, because you are thinking vacuum line, was the recall done for the brake booster?

orion445

I am having the same problem, I have an 06 XL with a 4.6. Can you tell where its coming from? I cant tell if its in the engine compartment or the rear end. I can hear it real good at 45 and above,cant hear it 40 and below.
Really odd.

Dark Stone

I didn't have it done but when I bought my truck I had it checked for open recalls and there were none so I'm guessing it was either done or my truck wasn't affected.

Bhale- very interested to see what your mechanic says. I took it to the dealer I'm still under warranty but they could of course not hear the noise. I even had my 5 year old confirm that she could hear it so I knew I wasn't going crazy.

John

bhale943

I did not have the recall done yet. Took the truck to the mechanic, and same story, "Problem could not be replicated". Things have been warming up in my area and sound has not returned in the last day. My suggestion would be get it real warm and let things melt.
Just a possibility, but on my truck-05 fx4 5.4, I go through atleast 1/4 quart of trans. fluid every 3k, with no leaks visible whatsoever. Possibly, the combination of very cold weather and lowish trans fluid could have caused the whine.?
Sound is most definitely coming from the firewall area, but penetrates the whole vehicle-almost sounding stereo feedback like--making my brain twitch.
I will keep you updated of sound returns, solutions etc. Thanks, Brian

Dark Stone

I'm wondering if it a bearing in the AC compressor. I believe that when I'm using the defrost the AC compressor kicks on and off. What does anyone think of that possibility?

It's warmed up around here in the last day as well and the noise has not happened in the past day of so.

John

viennafireman

The noise your hearing is coming from your alternator bearing. My truck makes this noise as well. I am a parts manager for a ford dealership and the service managers truck makes this noise also. I have noticed it around 1800 rpm when it is below 30 degrees outside. When the truck warms up the noise goes away. Also watch your amp gague when the truck is making noise youll notice it will go to 3/4. My truck has done it for the better part of a year with no problems yet, but Ford says there is nothing wrong with it.

Dark Stone

I'm glad I at least know what it is now. I'm going to go to the dealer to see if they can do anything about this or not. The noise is really load and irritating and it's cold here for 5 months a year.

Thanks everyone for the input..


John