Engine whine/noise

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Emerscape

NAXJA Forum User

Location

Boston, MA

• Sep 21, 2009

• #1

Cracke the head on my 2000xj a couple months back and recently had the head replaced. I'm getting a whining noise that sort of sounds like a higher pitch of when you blow air across the top of a beer bottle. Doesn't make the noise when idle or at cruise, but I can hear it when accelerating. Very hard to hear it sitting inside the jeep, haven't had a chance to rev the engine to see if I can pinpoint it. Any ideas where I should start looking?

 

joe_peters

NAXJA Forum User

Location

Grants Pass, OryGun

• Sep 22, 2009

• #2

Intake leak somewhere. You can use an unlit propane torch and hunt for it.

 

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Emerscape

NAXJA Forum User

Location

Boston, MA

• Nov 12, 2009

• #3

Hey Joe,

Haven't had a chance to check for the intake leak. I've posted elsewhere about having a slightly rough idle which is back after changing my spark plugs. They all mention to check my vacuum lines but I don't know what those are or how to check them. Can you give me some direction on that?

Also can you tell me how and where I should try the propane torch test to look for an intake leak?

Thanks

 

joe_peters

NAXJA Forum User

Location

Grants Pass, OryGun

• Nov 12, 2009

• #4

Hey, long time you've been putting up with this problem.

Warm the engine up. You could hook up a tach gauge, but usually not necessary. With the engine idling, crack the valve on the propane torch and then move the tip around the engine's intake manifold, throttle body, and vacuum lines--listen for an increase in RPM, should be very obvious. Take your time and be patient. If you don't find something on the first try then do it again.

 

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Emerscape

NAXJA Forum User

Location

Boston, MA

• Nov 12, 2009

• #5

yeah I know... I guess I don't drive it enough to really let it bother me. Plus I live downtown in the city so it's not like I can really pull my jeep into a garage. With only 610 sq ft in my condo it's kind of hard to keep a good set of tools.

Where are the vacuum lines?

I'm going to try to get a video of the engine up this weekend as I'm getting another noise that kind of sounds like the power steering whine but my power steering seems fine.. I think it might be an idler bearing..

thanks for the help.

 

joe_peters

NAXJA Forum User

Location

Grants Pass, OryGun

• Nov 13, 2009

• #6

Any rubber/plastic lines attached to the intake manifold, the brake power booster, and lines will run to the cruise pot and HVAC controls.

 

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Emerscape

NAXJA Forum User

Location

Boston, MA

• Dec 7, 2009

• #7

I was looking at the rubber line that attaches to the top of the valve cover (unfortunately I've not had a lot of free time lately) and it looks a little loose on top of the valve cover. is this normal? is this a vacuum line or just a breather?

I've been getting terrible gas mileage lately ~ 10mpg around the city... and I mean city traffic in downtown boston. I drove it back to my mom's house in CT and got 17.65 mpg with a mix of 70% highway and 30% backroads, hilly, berkshire driving...

 

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Emerscape

NAXJA Forum User

Location

Boston, MA

• Feb 16, 2010

• #8

I know this is an old thready but I haven't had time to track this thing down. spent some time listening to it the other day and it sounds like it is coming from the intake manifold. I wanted to retorque the bolts but couldn't seem to get my torque wrench in there to torque the bolts. Any suggestion on how to do this?

 

joe_peters

NAXJA Forum User

Location

Grants Pass, OryGun

• Feb 16, 2010

• #9

Emerscape said:

I know this is an old thready but I haven't had time to track this thing down. spent some time listening to it the other day and it sounds like it is coming from the intake manifold. I wanted to retorque the bolts but couldn't seem to get my torque wrench in there to torque the bolts. Any suggestion on how to do this?

Click to expand...

Frustrating, isn't it?

This is a common problem. The real world answer is to "feel" torque them. Sounds Ghetto, but sometimes that is all there is.

 

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Emerscape

NAXJA Forum User

Location

Boston, MA

• Feb 16, 2010

• #10

so instead of trying to use a socket just grab a wrench and tighten them a little?

 

joe_peters

NAXJA Forum User

Location

Grants Pass, OryGun

• Feb 16, 2010

• #11

On the ones you can't get to with a socket and torque wrench, yes.

The best wrench for the manifold bolts seems to be a flex-head ratcheting box wrench. The GearWrench 14mm runs about $12 at Lowes.