A little help?--A new, annoying sound

Discussion in 'Fiesta ST Maintenance' started by jimclark, May 31, 2014.

  1. jimclark

    jimclark Active Member

    For the last several days I've been hearing a moderately high-pitched sound coming from the engine bay, seemingly from the passenger side, as I drive. The sound is associated with engine RPMs of about 2-3K and is heard almost entirely when the engine is under load. When sitting in neutral, I can rev the engine through that range with little or no presence of the noise. It sounds a little bit like a "whine". Car performance seems unchanged, and good--no complaints there. In fact, I have the impression that the sound is more noticeable, perhaps more present, when the engine is in the RPM range above, under moderate load. Under higher load, I don't notice it, though of course there's more engine noise/sound in general then.

    Anyone got any idea what's causing it? Since it's now lasted several days, I'm planning a trip to the dealer come Monday to have them try to figure it out and eliminate it. That said, I'd love to have a good idea of what it is before then.
     
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  3. WScottCross

    WScottCross Well-Known Member

    Turbo spool? Have you changed fuel recently?
     
  4. jimclark

    jimclark Active Member

    I was wondering about something turbo-related, but (a) it's not as consistent as I'd expect turbo-spool to be, and (b), wouldn't that be made greater as I punch it harder? In my case, the noise seems most prominent at grandma-going-to-church type driving. (Noting of course that as I press harder on that skinny pedal, lots of things get louder.)

    I've not (knowingly/intentionally) changed fuel lately. Interesting tidbit, though: the gas station I often use (filling with 91 octane) and that I used this last time also has a touchless car wash, and I took the car through the wash early in the week. It was immediately after the car wash that I noticed the sound. No idea what that means, if anything.
     
  5. Jaytech

    Jaytech New Member

    There has been a lot of discussion of tranny whine. Mainly at lower rpm's under load in 5th or 6th gear. I notice it when accelerating on the freeway, ie, if I get slowed down to 50-55 then accelerate back up to 70 ish it will whine while on the throttle. And this just developed at around 2500 miles.
     
  6. jimclark

    jimclark Active Member

    I really don't think it's to do with the transmission, based on where the sound is coming from--it's clearly emanating from the engine bay, and it is very much rpm related, at modest loads. Pretty much all gears, I think, although at highway speeds it starts to get lost in the road and ambient noise.
     
  7. I have had the same noise. I noticed it within a week of picking up the car. To me it sounds disturbingly like a terminal bearing. 7K miles later and nothing has gone belly up. Annoying at low speeds but seemingly harmless.
    MH
     
    jimclark likes this.
  8. 1FocusedHokie

    1FocusedHokie Member

    I'm experiencing this, too. I puchased my ST with 6k miles on it and after driving it for about a week, I was fairly alarmed by the sound. At first I thought it was alternator whine/feedback coming through the speakers. After turning off the stereo and it still being present, I guess that's not the case. It's definitely under load and when on the throttle, typically between 2500-4000rpm. Has anyone called or talked to a Ford service dept about this?
     
  9. RodMoe

    RodMoe Well-Known Member

    Jimclark did the car wash use a "underbody flush" at the start as you drove in ??
     
  10. Steve@Tasca

    Steve@Tasca Fiesta ST Network Sponsor

    Only does it under load, no noise when sitting still and in neutral?

    -Steve
     
  11. 1FocusedHokie

    1FocusedHokie Member

    That is correct. Under load, typically between 2500 and 4000rpm.
     
  12. jimclark

    jimclark Active Member

    Yep, if I recall correctly. It was their middle choice. Only second time I've taken the car through a car wash rather than doing it myself. Does that give you some thoughts? BTW, the sound is persisting, and, if anything, is sounding more noticeable, and I think is more consistent. As soon as practicable, I'm gonna try to get it over to the dealer with the sound present so a good tech (I hope) can get a listen, and go from there.
     
  13. jimclark

    jimclark Active Member

    Steve--I almost completely agree with 1FocusedHokie. That said, on occasion I can hear a slight bit of the same noise when in neutral and sitting still, but it's not nearly so noticeable/prominent. And for what it's worth, it can be heard both inside and outside the car, at least when it's at its most noticeable. My father's 75-year-old ears could pick it up without difficulty, standing nearby as I drove past the house.

    As for the RPM range, I'd now go with 1FH's description as the more useful general range in which it's heard.

    I also agree that it sounds disturbingly like a belt/bearing/drive sort of noise, though it's not seemingly affecting car performance much, as far as I can tell. (No fault codes, and its performance seemed good over a 2500-mile round trip to Salt Lake City I just completed.) There are moments at which I don't hear it at all, even in the RPM range noted, and times when, like this evening when out with the wife, it seems incessant, and if driving at a steady modest load that produces the sound, it is constant.
     
    Last edited: Jun 14, 2014
  14. jimclark

    jimclark Active Member

    I had the classic experience, about 10-14 days ago, of taking the car by the dealer and having it (the sound) be so light and subtle at the time that I couldn't be sure I heard it. The tech, of course, heard nothing. I'm looking for the tactical opportunity to get it there when it's anything but subtle, to establish at least that (a) there's a sound, and (b) I'm not nuts. Well, not completely, anyway.
     
  15. RodMoe

    RodMoe Well-Known Member

    My thought of the wash maybe spraying on a hot exhaust or engine pulley or belt . But it's just a guess .. Maybe the cold wash water stressed a exhaust flan for drive/driven pulley. I know on my truck I have a chirp that comes and goes and about the time I'm fed up enough to tear into it it stops for a few weeks .. Typical right
     
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  16. 1FocusedHokie

    1FocusedHokie Member

    I have an appointment later this week. I'll update this with any info.
     
  17. jimclark

    jimclark Active Member

    Thx, 1FH--I'm looking for a good opportunity to take it in when no one's gonna feel rushed, leading to the "Well, leave it and we'll take a look and call you," scenario. That seldom solves my problem if I don't have a pretty good idea what it is already.
     
  18. 1FocusedHokie

    1FocusedHokie Member

    Well Ford said nothing was wrong. The tech that looked at my car has a Focus ST and said he has a similar sound that's due to the performance tube that's basically there for sound effect. I believe I will need to remove said tube if that's the case. Still not convinced there isn't an issue, but I guess I'll leave it be for now. I wanted to have this addressed before I even thought about mods, so I'm not sure if I should just let it go and mod or wait it out some more. I don't have anything drastic planned, but I don't really want any chance of warranty argument if there's a previously existing condition that modding wouldn't have caused.
     
  19. Steve@Tasca

    Steve@Tasca Fiesta ST Network Sponsor

    You can always ask for a demonstration that other cars do the same thing, new/used car would do.

    -Steve
     
    SpaceFish likes this.
  20. 1FocusedHokie

    1FocusedHokie Member

    Good idea. I might stop by again over the weekend and ask. Thanks, Steve.
     
  21. Steve@Tasca

    Steve@Tasca Fiesta ST Network Sponsor

    It's actually quite a common thing to do especially if it is in fact a "Normal operating characteristic".

    -Steve
     
    SpaceFish likes this.

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