By on June 20, 2019


Matt writes:

Hi Sajeev,

I wrote to you a few years ago regarding a water leak in the moonroof of my old 2010 Ford Fusion. I traded that car in 3 years ago on a brand new at the time 2015 Fusion Titanium with the 2.0 Ecoboost and AWD.

I have had this car for 3 years and just rolled over 100,000KM with it. My issue is that under hard acceleration from a low speed or a stop there is a whining noise that sounds like its coming from the front of the car. The whining noise sounds like the whine a supercharger makes. If i accelerate gently there is no noise and if I floor it on the highway there isn’t a noise I can hear either.

It seems to be only a low speed thing and heavy on the throttle that recreates it.

I took the car to the dealership last week while it was under warranty and they claimed it was the turbo and replaced the turbo and a number of associated parts. The car is still making the noise under the same conditions and now my warranty is done. I’ve googled the issue and been on the Ford forums and couldn’t find anything related to the noise i’m experiencing.

Any idea why my turbocharged 2.0 Ecoboost sounds like a supercharged engine?

Sajeev answers:

Supercharger whine is a delicious thing, not so much when its turbocharger whine.

My initial feeling was that the source is a loose turbo plumbing somewhere between the air filter and the throttle body.  That’s because higher engine loads/boost levels cause stresses in forced induction plumbing not seen at lower throttle inputs, causing the loose piece to break its “seal” with the rest of the system.  Usually that leak causes performance issues, as boost flies out of the system and throws the anticipated air/fuel ratio out of whack. Not so here!

My best guess?  There’s a body plug (AKA grommet) either missing or improperly installed: more likely if you put an aftermarket amplifier power wire  (i.e. an old school amp, not the digital ones that are easy on power requirements) using a factory grommet to feed the wire past the firewall.  It’s a long shot if you’re running a stock stereo, but still worth putting the Fusion on a lift to verify!

What say you, Best and Brightest?

[Image: Ford]

Send your queries to [email protected]com. Spare no details and ask for a speedy resolution if you’re in a hurry…but be realistic, and use your make/model specific forums instead of TTAC for more timely advice.


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26 Comments on “Piston Slap: That Ecoboost Turbocharger Whine?...”

  • avatar

    If they didn’t resolve your under warranty concern while it was under warranty, the warranty is not done. They still have to fix it. Take it back and tell them the issue wasn’t resolved.

  • avatar
    Jason Bright

    My old turbodiesel Golf used to make a supercharger type of whine under load. I think the bearings in the turbo itself were shot

  • avatar

    “Any idea why my turbocharged 2.0 Ecoboost sounds like a supercharged engine?”

    Because Ford Quality.

  • avatar

    Unpossible because turboz is awesome.

  • avatar

    A bad idler pulley bearing will do that. Cheap fix.

  • avatar

    On my 2007 Civic Si, one of the firewall grommets (clutch pedal, I think) came unseated during a warranty clutch replacement. I could hear excess “engine hiss and tick” after the dealer reassembled the car, but the service adviser and shop foreman insisted the newly-present noise was normal. After some investigation with a flashlight – on my own, I found it. It was amazing that the dealer denied it until I pushed hard enough and finally had evidence. I think perhaps some mechanics’ hearing lacks range due to the accumulation ear drum damage – from shop noise.

  • avatar

    Even for a dealer, I’m surprised they went as far as replacing the turbo and it didn’t do anything.

    I think Sajeev is on the right track. Did someone pull off the sound insulation from under the hood?

  • avatar

    Clickbait headline – Sajeev says he’s thinking it has nothing to do with the turbo, as most commenters agree. So, the headline – ?

    “Piston Slap: That Ecoboost Turbocharger Whine?…”

  • avatar

    I’ve got a solution for this problem its: “put the vehicle for sale – and FAST”

  • avatar
    James Charles

    Axial flow compressors (as opposed to centrifugal flow) create axial and thrust loads on the bearings.

    The thrust load is what forces the compressor spool to react against the harder working compressor. This forces the spool’s shaft to increase its thrust bearing load.

    I would guess you have a bearing issue. What caused this? Temperature. Oil is used to cool and lubricate the bearing. Manufacturing defect. The bearing itself might not be of the quality. To much boost and/or driving to hard. Or all of the above.

  • avatar

    Turbos really should make more of a whistling sound when working hard, and not a whining sound. The whining sound is more likely a bearing of some kind. The turbo was already replaced, so the turbo bearing should not be to blame. It could be something in the drive pulley system. An idler pulley (cheap).
    A water pump (semi-cheap). However, it also could be something bad and expensive, like a failing transmission.

    It’s probably worth checking on Sajeev’s suggestion of a loose charge pipe connection.

    It’s hard to diagnose something that only happens under a load, but there are some shops that have dynamometers and scan tools (maybe tuning shops for the most part). You could try to seek out one.

    • 0 avatar

      Years ago all my turbos had a slight hoo or whistle…SAAB 900T, aftermarket VW Callaway system, a few others. My current cars, VW gas turbo, or Benz V6 turbos…nothing. Rented an EcoBoost Mustang, it too was totally silent.

      I read somewhere that the hoo was the tiny imbalance in the impeller…maybe they are perfect now ?

  • avatar
    White Shadow

    I can’t stand supercharger whine, at least from a roots type blower. Worst sound ever. On the other hand, a turbo spooling up is a fantastic sound. Unfortunately, modern turbo engines insulate the turbo spooling whistle from the passengers so they tend to be hard to hear.

  • avatar

    Dear Sajeev,
    There’s a sucker born every minute. Today, YOU are that sucker.

  • avatar

    Could be a noisy alternator, compressor or ps (if so equipped).. You can pull the serp belt off and see if it still makes the noise. Or ask the dealer to consider that test as an option if you decide to bring it back.

    Maybe you can compare to other Fusions? And… didn’t 90’s era Fords have the loudest power steering pumps? Could hear them before you saw them.

    Maybe it’s a feature.. : )

  • avatar

    A boost leak detector can be made for a few dollars worth of pvc fittings. Measure ID of your after cooler hose and find a suitable pvc glued fitting. Sometimes you may need to add a few wraps of electrical tape to make the fit snug, and finish off with an appropriate hose clamp to secure. Bush pvc fitting down to 1/4″ npt and add a male quick connect fitting. Hook up to a REGULATED hose off your air compressor equal to that of your vehicle’s waste gate psi. Soap all fittings once up to pressure.

  • avatar

    If it’s anything like a dental drill it is probably still the turbo…look for oil in the compressor side.

    It’s a Ford so you’ve probably got a thin plastic intake manifold…take a look at that also.

  • avatar
    cimarron typeR

    I’d like to know what it ultimately happens with this issue. Maybe post an update?

    • 0 avatar

      OP here, what ultimately happened was the car kept giving me problems and I dumped it a few months ago. Replaced it with a 2019 Mazda CX-5 GT Turbo, and wouldn’t you know it NO turbocharger whining noises.

      It started throwing CEL’s for an ambient temperature sensor failure. It also was stalling out on me while sitting in traffic. Which it did when I first bought it and they replaced a fuel pump modulator because it was telling the car it had more fuel than it actually did causing it to stall, so that issue came back. I had 4 tire blowouts in this car and the infotainment was glitchy as hell and the capacitive buttons were AWFUL.

      Also it was squealing on startup in cold weather so the dealership replaced the belts and the serpentine tensioner pulley but it still made the squealing noise. Oh and suspension squeaks and rattles, replaced shocks that never fixed the noises. It spent a lot of time at the dealership being “fixed”.

      It was a shame because I had 2006 and a 2010 Fusion’s and they were both fantastic and reliable cars. Just a leaky moonroof with the 2010 but otherwise I got 240,000 trouble free KM out it.

  • avatar

    Bad front wheel bearing(s). Have someone stand next to the car when you accelerate to hear which side the noise is coming from.

  • avatar
    cimarron typeR

    Fusion, thanks for the follow up. I love this segment but sometimes we’re left hanging on what happens after we post our 2 cents (or less)
    Congrats on the 6!I guess you should change your user name.

  • avatar

    I know it’s long gone, but I would suspect transaxle gear noise.

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