Strange, long wooooo sound at steady speeds, ICE on

[beadgalsarita]

I get the woo too, usually when accelerating with the gas motor (never with electric) usually kicks in around 20-25mph and will continue until I stop accelerating or get going fast enough. It doesn't happen every time, but often enough.

 

edit to add: got the woo tonight while on the highway. going 60-65mph. the heat/ac was not running. as far as I can recall, I've never heard the woo while driving that fast before. It was also hard to get it to go away. The only option was to step off the gas, but I couldn't do that for long as I needed to keep a safe speed.

Edited March 1, 2014 by beadgalsarita

[techman05]

Hopefully its the same thing except to me I had like a fish tank sound. I went it complaining about it and they found the presure was off by a miniscule amount and they re presurized some pump and bled it like a radiator and haven't heard it since.

 

Apparently its a hybrid thing and that I should get used to strange things. I'm going in for a fuel inlet error tommorow so hopfully that'll be  as quick fix as this.

[Dave Greene]

I have a 2013 C-Max Energi and I've experienced what sounds like a "woo sound" for the past few weeks each time the ICE engages.

 

I took the car in to the dealer today to get a couple of the recalls looked after and mentioned the sound. They called me back late in the afternoon to say that it's the fuel pump and they've ordered a replacement.

[Dave Greene]

I have a 2013 C-Max Energi and I've experienced what sounds like a "woo sound" for the past few weeks each time the ICE engages.

 

I took the car in to the dealer today to get a couple of the recalls looked after and mentioned the sound. They called me back late in the afternoon to say that it's the fuel pump and they've ordered a replacement.

 

Fuel pump replaced. Noise is gone.

[banditb17]

I don't know if it is the same thing, but I did notice a harmonic resonance at a very specific RPM of my ICU. It is a little annoying but doesn't take much to push it over that specific RPM to make things quiet again.

 

Maybe I can take video of it to see if it is similar.

[Rpshipley]

I too have noticed this "Woo" sound.  We get it above 65 mph steady travel either ICE or battery.  Also noticed if there is a strong cross wind on the highway.  Suspect it is a resonance in the rear vent system as air is trapped in there.

Edited September 15, 2014 by Rpshipley

[FordService]

I too have noticed this "Woo" sound.  We get it above 65 mph steady travel either ICE or battery.  Also noticed if there is a strong cross wind on the highway.  Suspect it is a resonance in the rear vent system as air is trapped in there.

 

You might want to have your dealership inspect, Rpshipley; they'll be able to recommend any service actions, if needed. How many miles do you have on your C-MAX?

 

Crystal

[C-MaxSea]

Or was it just the Whos Wooooing down in Whoville ?  ;)

[wb8nbs]

I've talked to the Service Department rep twice about this and both times he blew it off.  "Hybrids make a lot of noises". The car still does the noise but have only seen it get loud a few times this summer.  It is specific to a certain RPM and load on the engine but as your foot does not directly control the throttle it is hard to induce the moan manually. It was more prevalent last winter (Chicago area), will see how it does in the months to come.

[C-Max Smith]

My 2013 C-Max is making the same noise.  The dealer had it three days and could find nothing.  They think it might be electrical. Ford said to compare it against another 2013.  It occures at all speeds and sounds like a bearing or belt in the tire.  I have not tried the "recirc" on the a/c.  The car was much quiter before this woooo noise started.  I am very happy with my vehicle and averaging 44 mpg.

[C-Max Smith]

My 2013 C-Max is making the same noise.  The dealer had it three days and could find nothing.  They think it might be electrical. Ford said to compare it against another 2013.  It occures at all speeds and sounds like a bearing or belt in the tire.  I have not tried the "recirc" on the a/c.  The car was much quiter before this woooo noise started.  I am very happy with my vehicle and averaging 44 mpg.

[scottwood2]

I don't know if it is the same thing, but I did notice a harmonic resonance at a very specific RPM of my ICU. It is a little annoying but doesn't take much to push it over that specific RPM to make things quiet again.

 

Maybe I can take video of it to see if it is similar.

This is the sound I get too.  Done this since it was new.  I you get the ICE RPM right then it will vibrate.  A little more push on the gas pedal or a little less and it goes away.  Seems like a major vibration issue in the drivetrain to me.  I don't think the fuel pump would do this but I could be wrong. 

[kostby]

Dave Greene above posted in message 29 of this thread that replacing the fuel pump cured the noise:

http://fordcmaxhybridforum.com/topic/3457-strange-long-wooooo-sound-at-steady-speeds-ice-on/?p=43287

 

But now you should probably wait until after Halloween!

Edited October 28, 2014 by kostby

[wb8nbs]

Cold weather is here again and the C-Max is making the noise often. Might be able to take a service tech for a ride soon.

 

[FordService]

My 2013 C-Max is making the same noise.  The dealer had it three days and could find nothing.  They think it might be electrical. Ford said to compare it against another 2013.  It occures at all speeds and sounds like a bearing or belt in the tire.  I have not tried the "recirc" on the a/c.  The car was much quiter before this woooo noise started.  I am very happy with my vehicle and averaging 44 mpg.

 

This is the sound I get too.  Done this since it was new.  I you get the ICE RPM right then it will vibrate.  A little more push on the gas pedal or a little less and it goes away.  Seems like a major vibration issue in the drivetrain to me.  I don't think the fuel pump would do this but I could be wrong.

I know it's been a few weeks, C-Max Smith and scottwood2, but how are your vehicles doing? Are you all still hearing the noise?

 

If so, please send me a PM with your full names, best contact numbers, current mileage, VINs, and preferred dealers.

 

Cold weather is here again and the C-Max is making the noise often. Might be able to take a service tech for a ride soon.

Let's see how I can help your C-MAX stop protesting the cold weather, wb8nbs. ;)

 

Have you made an appointment with your dealer? Please send me a PM with your full name, best contact number, current mileage, VIN, and dealer info; I'll check my resources.

 

Rachel

[wb8nbs]

Cold weather is here again and the C-Max is making the noise often. Might be able to take a service tech for a ride soon.

Well, I took it in on the 30th Dec. and just as Edsel Murphy predicted it would not make the noise that day. Ford Tech put about 10 miles on the car and they never heard it. I did get my complaining documented and they said to bring it right in if it started again.

[drdiesel1]

I really wish the dealers had people that could at least perform the standard TSB search before wasting time on things. IDK if this is your problem, but this TSB should be researched before wasting time driving around with zero results. It's a simple practice, yet they seem to be oblivious to the obvious. It's not the full article, but it has the TSB info you'll need.

 

 

Good luck with your problem and I hope this helps.

Edited January 2, 2015 by drdiesel1

[wb8nbs]

Thanks for that. I have the whole TSB now, will wave it in the dealers face next time I'm over there.

 

 

I really wish the dealers had people that could at least perform the standard TSB search before wasting time on things. IDK if this is your problem, but this TSB should be researched before wasting time driving around with zero results. It's a simple practice, yet they seem to be oblivious to the obvious. It's not the full article, but it has the TSB info you'll need.

 

 

Good luck with your problem and I hope this helps.

Untitled-1.jpg

[Jenie Benson]

My 2013, June build, is at the dealership for this right now.  I started having this issue at about 800 miles and I'm at 20,520 now.  Dealership had been unable to determine the problem until now because they couldn't hear the noise last winter and mine only does it at 15 degrees or below outdoor temp.  

 

We'll see if the TSB solves it, I'm not optimistic since there is a horrendous vibration that goes with the noise (which I think sounds like a very resonant WWWWWWAHHHHHHHH at about 2000 RPMS) and mine only happens below a certain outdoor temperature.  I am still of the camp that something is wrong in the drivetrain.  No amount of noise cancellation manipulation is gonna make that go away.   I guess we will see when they finish the TSB tomorrow.  

 

2 days I'm gonna have to miss work cause they were out of loaners at the dealership and the rental place they use is out of cars and apparently they do not have a backup - try explaining that one to your boss when your car is still under factory warranty and you can't get to work.

[wb8nbs]

An improperly wired microphone in a noise cancelling system could cause the sound system to go into oscillation and would explain why the noise seems to be coming for the foot well on the passenger side I think ther's a speaker there. Can we blame Microsoft?? Please???

 

I didn't even know it HAD a noise cancelling system. I think it's a good bet that it's the problem.  Wish there was a way to disable this "Feature", that would tell me for sure when it starts doing it again.

 

I had a call from the regional manager, they're working on it. Film at 11:00.

[drdiesel1]

An improperly wired microphone in a noise cancelling system could cause the sound system to go into oscillation and would explain why the noise seems to be coming for the foot well on the passenger side I think ther's a speaker there. Can we blame Microsoft?? Please???

 

I didn't even know it HAD a noise cancelling system. I think it's a good bet that it's the problem.  Wish there was a way to disable this "Feature", that would tell me for sure when it starts doing it again.

 

I had a call from the regional manager, they're working on it. Film at 11:00.

What happens when you turn the audio system OFF ? Is the noise gone ?

Isn't the system only active with the audio system ON ?

Edited January 9, 2015 by drdiesel1

[Jenie Benson]

Had my Energi in for 3 days this week and they performed the TSB related to the Noise Cancelling system to try to rid my car of the horrendous vibration accompanied by loud WWWAAHHHH noise.  Drove to work this morning and car did it again while entering the freeway and in traffic. Not fixed.  Not the problem (though yes, I could see how the system could amplify sounds if not configured properly, but that's clearly not the issue with my car). Spoke with a regional service manager today and he already received escalation of my problem before I even called him.  Car will have to go back for more investigation into the issue for unknown length of time. Dealership is attempting to line up a rental for me though the rental places are all sold out right now and the loaners are all borrowed out at the dealership. Regional service manager says he will have to get engineering involved in solving the issue since it's been an ongoing problem that is getting worse and it's a tricky one.  I'm keeping track of how many days it's been in for warranty stuff, cause sadly, we are inching towards threshold for lemon-law buy back and I'm starting to wish I'd bought something else.

[Jenie Benson]

What happens when you turn the audio system OFF ? Is the noise gone ?

Isn't the system only active with the audio system ON ?

no, it's always on.  It uses the speakers from the audio system to do it's thing, but it's always on even if the audio isn't.

[drdiesel1]

I wouldn't worry to much about it. It's not like it's something they can't sort out and

it isn't making the car unreliable or unsafe. Yes, it's annoying, but the car is a very

great set of wheels and you would be unhappy without it. I know, I was for 4 months

and had to buy another one. Last time I let that happen. Give them some time to fix

it and you'll be glad you did :wub2:

Edited January 9, 2015 by drdiesel1

[wb8nbs]

I have a good recording of the noise! This is coming off a traffic light on Jan 22. Outside temp was 31F, the heater is off. Two people in the car.  Recorded on a Nook tablet.

 

In the file, noise at 0:15, and again at 1:05 briefly. RPM to get the noise going (I finally found the tachometer) is about 2400.

 

The file name is C-MaxWooo.mp3

 

Spectral display shows a 15 db peak at 159 Hz. That would be twice the engine firing rate at 2385 RPM which is consistant with the tach reading.

 

Hope This Helps.

C-MaxWooo.mp3

Edited January 22, 2015 by wb8nbs