Nisty

Hi everyone. I am new to Ford trucks, and I must admit that I do like this truck, but as the weather is now turning colder I am noticing a problem. The truck is an '05 F-150 4x4 super cab with the 4.6L and has about 43000 km. When driving in cold weather up here I am starting to hear a very loud "whistling" or "whining" noise. The noise had never happened during idle, but instead comes and goes during cruising speeds and occasionally when the tranny is cycling through gears (always the top end of the gear). Taking my foot off the gas pedal for a moment always puts an end to the noise, but it tends to return with normal cruising rpm's. Only when the engine is completely warmed does the noise seem to disappear, and even then it returns from time to time with normal driving. I have seen some info on this posted here and on other sites but most was with regards to the 5.4L engine. So I am just wondering what could be the cause of it in this engine. I keep seeing the same three guesses at what it could be. 1) Cold air passing through the nylon tube in the idle-air bypass flow circuit or through the throttle body 2) A pulley and/or belts. 3) The fan. If anyone could shed some light on this for me so I have some ammo to take to the dealer I would appreciate it. I'd like to get this taken care of or else it will be a long cold Canadian winter listening to this noise. Thanks.

Jackhammer

I myself just posted on another forum regarding this and in my google searchs for fixs for the problem I found your post. I also live in Canada (ontario) I bought my struck a few weeks ago and now have this damn problem it is most annoying!

I also have a 2005 Ford F-150 4.6L and the problem with mine is exactly the same as yours. I spend most of my time driving for work so you can see how this noise would drive me insane!

Please let me know how you make out with this problem... I am hoping to get time to get in to the dealer this week and see what they have to say.

Nisty

Jackhammer.....

Good to know I'm not the only Canadian with this problem. My plan is to contact the dealer I bought the truck from which was in Winnipeg. I have a distant family member working at that dealership so I'm hoping that she can give me some straight answers from the service department there, rather then run the risk of getting the run around at my local dealership here in Thunder Bay.Then with any information I do get from her, I plan to take to the local dealership as ammunition. I have read from other people's posts that some dealerships have been giving poor excuses for the problem and refusing to investigate or fix the problem. Calling the noise a "normal operating noise". So I will post my response from the dealership I bought the truck from later this week if you wish return and see what they had to say. If you get to yours first, I would really appreciate to hear back from you. I just hate going into those dealerships blind. Thanks for the post.

Jackhammer

sounds good... on a better note today with the warmer weather here around -1 the noise went away which is nice!!! I did goto canadian tire aswell and got some belt dressing for it. From my reading on this it seems that it is the rear bearing in the altenator that is making the noise...... i dont know how but again from my reading online people have been having the altenator replaced under warrenty and it fixs the issue.

I will be at the dealer tommorrow morning to see wha they say and asoon as I get the chance I will post back.

Nisty

Alternator eh? Would not have thought about that right away, but It makes sense. Like I mentioned earlier, I've read a couple of different things it could be so I hope the dealership can pinpoint it without too much investigating. I bought the extended warranty coverage with the truck when I purchased it in August so I think I'm covered for something like that. The weather here has also been better then it has been recently so I too haven't noticed the problem . But soon it will be -40 up here and I can't imagine the noise it'll make then if I don't get this fixed. Well thanks for the info, and I look forward to hearing what the boys at Ford have to say.

Nisty

Jackhammer....I called the dealership in Winnipeg i bought the truck from and the said that they have dealt with the problem before. Although they could not tell me exactly what it was, they said it was not an air intake problem, and that is was something on the belt line...most likely the alternator. So I went to the dealership here in town and they confirmed that it was most likely the alternator but they needed to hear it for themselves first and it's been mild here so I have to leave it with them on a cold day sometime soon. I was told that in cold weather the stator inside the alternator actually shrinks enough to cause binding problems with the rotor. They've seen it before and usually swapping out the old one with a new one gets rid of the whistling noise. So like I said, I will wait until it is cold enough to have the techs at the dealership confirm it and then I'll have it swapped out. I'll keep you posted. Also was wondering how you made out with your truck at the dealership? Would love to hear what they had to say to you about the problem. I should have an update by next week.

Nisty

PROBLEM SOLVED!....Turns out it was the alternator. A tech from the dealership heard the sound for about 3 seconds and said that it was for sure the alternator and that a replacement should get rid of the noise. He said that the problem has turned up before on some 4.6's, but not a huge number. My concern is that they replace the alternator with the original model, so technically I could end up in the same spot down the road. But we'll cross that bridge if we get there. I'll have the truck back tomorrow morning and I'll be the judge of whether or not the noise is gone for good or not. I'll post it.

titan113

I have the same problem - we went to the dealership and they told me it was an air intake problem and there was nothing they could do - you could imagine my frustration! Was it the alternator?

Nisty

Yeah, it was. The alternator was changed out and the problem is gone. I had to get the shop foreman to ride in the truck with me on a cold day to prove that the noise existed. He took one listen and confirmed that it was for sure the alternator. That what last week...this week the truck is back to the shop for a multitude of problems. My heater fan was revving up and down on it's own. the engine started making a weird ticking noise, and to top it all off my hubs kept trying to lock up on their own and now they need to be replaced. It's still all under warranty, but when I bought a newer vehicle I thought I would be avoiding all these problems. Hopefully this will be the last of them.

Oh yeah, if your rear end is clunking on slow speed turns or when the body rolls side to side, get the shop to check your rear springs. That was my second last trip to the dealership. Apparently the need some kind of special lubrication. Ford knows about the problem.

Good luck with your whistle.

titan113

Thanks