Buzzing / Whine coming from driver's-side engine bay

weeks101 · **Joined:** Mon Jul 30, 2012 3:29 pm **Posts:** 747

Sound clips:

From inside cab: https://soundcloud.com/theshocker-1/crd-noise
Under-hood: https://soundcloud.com/theshocker-1/crd-noise-2

Noticed this on my way to work this AM so I haven't had much time to diagnose. This whining or buzzing sound can be heard from the driver's side of the engine bay, inside and outside of the vehicle. It seems to be dependent on load ("throttle") rather than RPM, but it seems to only occur at or above 1,700 RPM. A quick inspection did not reveal any fan or belt contact with any parts. I am not noticing any changes in driveability or vehicle behavior other than this new sound.

Any thoughts as to what this could be?

*edit: added 2nd, better quality sound clip.

papaindigo · **Posted:** Tue Jan 29, 2013 11:32 am

Not at all sure I hear anything but from that area the 1st 2 things I'd look at would be alternator clutch (open hood, have someone hold engine at high idle like 1200 rpm, look down the serp belt from the alternator clutch pulley, if your serp belt tensioner is noticably bouncing your alternator clutch pulley is shot - can be replaced but best bet may be Autozone or such lifetime warranty replacement of entire unit) and the flow control valve butterfly (where driver's side CAC hose connects to engine, this has a plastic gear that can strip causing the valve motor to run all the time or some such)

weeks101 · **Joined:** Mon Jul 30, 2012 3:29 pm **Posts:** 747

I replaced the alternator with a brand new Autozone unit in the fall. It's showing no signs of failure.

Gokeeper · **Posted:** Tue Jan 29, 2013 12:06 pm

As papaindigo mentioned, check the FCV Flow control valve, Mine made a heck or a racket when it went bad (Plastic gear breaks)

kjjet · **Posted:** Tue Jan 29, 2013 1:45 pm

That is a strange noise. It sounds like somthing is turning at a high RPM. I hope its not the High Pressure fuel pump.

Likewise i would check all the accessories, you may want to remove your serpentine belt and try it? You can just unplug your flow control valve to test.

If you still can not find and think it may be in the pump, Try adding a lubricant to your fuel. They sell several types like Power Services. I use Lubribor in every fill up. But it can be hard to find. Some use 2 cycle oil, but my experience is not so good with its use.

weeks101 · **Joined:** Mon Jul 30, 2012 3:29 pm **Posts:** 747

I sure hope it isn't the fuel pump.

What about a leaking CAC hose?

kjjet · **Posted:** Tue Jan 29, 2013 2:51 pm

Could be, but sure sounds like somthing turning or spining at a high RPM.

weeks101 · **Joined:** Mon Jul 30, 2012 3:29 pm **Posts:** 747

But would the fuel pump run at a higher RPM along with engine RPM?

Here is a better quality recording I took tonight: https://soundcloud.com/theshocker-1/crd-noise-2

papaindigo · **Posted:** Wed Jan 30, 2013 10:22 am

Ok I can clearly hear a "scree" noise on 2nd clip at several points; 1st at 26 seconds. Sounds like a possible failing bearing if it's not the FCV. I like kjjet's suggestion about removing the serp belt for a test. That belt runs a number of things with bearings that may be going. The serp does not drive (alternator, viscous heater, power steering pump, fan, AC) anything that matters for a short test run to see if the sound does/does not go away.

naturist · **Posted:** Wed Jan 30, 2013 10:23 am

I, too, think @papaindigo is on the right track suggesting the alternator clutch or the flow control valve, aka "the OTHER" EGR valve. That part is a known weak link with a high failure rate, and makes just such a noise often when needing replacement.

weeks101 · **Joined:** Mon Jul 30, 2012 3:29 pm **Posts:** 747

Correct me if I am wrong, but I was under the impression the flow control valve only came into play during engine shutdown.

Can someone explain under what circumstances the valve would cause this noise?

kjjet · **Posted:** Wed Jan 30, 2013 12:49 pm

The Flow control valve is part of the EGR system and directs exhaust from the EGR into the intake by limiting the amount of air provided thru the air intake system. The EGR works at part throttle.

weeks101 · **Joined:** Mon Jul 30, 2012 3:29 pm **Posts:** 747

Ok. Well I am not hearing the noise at part throttle. Only when the give it a fair amount of throttle (at load) and the boost starts to build.

Oh, and I have had my MAF unplugged so as to disable the EGR valve since I bought the Jeep last year. What effect does this have on the FCV?

kjjet · **Posted:** Wed Jan 30, 2013 1:08 pm

Several people have reported the FCV making noise, Mine is removed. It think since your MAF is unplugged it should be disabled also, But i would remove the plug and try it any way just to eliminate it.

Pulling the serp belt will eliminate allot.

weeks101 · **Joined:** Mon Jul 30, 2012 3:29 pm **Posts:** 747

Yeah, going to pull the belt soon. I'll also try unplugging the FCV to test that.

My main concern is, IF it is the CP3 fuel pump...am I harming any other components by driving it around like this with a (potentially) failing pump?

kjjet · **Posted:** Wed Jan 30, 2013 1:39 pm

I would not be concerned. Very few pumps fail. If it did the engine would shut off and the only thing it would effect is the injectors may get Contaminated.

I would check out everything else first. More than likely its somthing other than the pump.

weeks101 · **Joined:** Mon Jul 30, 2012 3:29 pm **Posts:** 747

Well I figured it out, finally. Thought I'd post the solution so others could potentially benefit.

Turned out to be the intake elbow gasket. $9 from IDparts: http://www.idparts.com/catalog/product_ ... ts_id=2769

Though the part was cheap, labor wasn't particular easy. Access to the elbow and the 4 bolts attaching it is tight. It required removal of the elbow and flow control valve. To get to those parts, youre best off removing the battery and fuel head. There is an EGR pipe connected to the FCV that's attached with a v-band clamp (http://www.idparts.com/catalog/product_ ... ts_id=3263). Getting that back on was the worst part of the job. Lots of trial and error.

kjjet · **Posted:** Sat Apr 06, 2013 8:48 pm

Glad you found it. Ya...messing with that EGR stuff is not fun. Mine is all gone.

Srytrucker · **Posted:** Thu Apr 11, 2013 3:21 am

My crd is having same issues and i just replaced the alternator and serpentine belt idlers and tensioner rollers with no improvement so next thing to do follow your solution. Can you please give more details on this.thanks.

Srytrucker · **Posted:** Mon Apr 22, 2013 3:11 pm

I am giving it a shot today hope it works.

Buzzing / Whine coming from driver's-side engine bay

Who is online