Whistling/Whining Noise

[moestoy]

Just bought a "new to me" '97 Jeep Wrangler SE; 2.5L 4 cyl.

On the way home it started making a whistling/whining noise. Test drove for about 30-45 minutes with no problems. Now as soon as it gets to temp (approx 5 minutes or less) it starts. Does not matter if AC is on or not.

Please help. :confused:

[aw12345]

Intake gasket leak?

[Mike]

Just bought a "new to me" '97 Jeep Wrangler SE; 2.5L 4 cyl.

On the way home it started making a whistling/whining noise. Test drove for about 30-45 minutes with no problems. Now as soon as it gets to temp (approx 5 minutes or less) it starts. Does not matter if AC is on or not.

Please help. :confused:

Check for disconnected or leaking vacuum lines too.

Does the sound change with the engine speed?

[moestoy]

Starts when engine gets hot, noise only on deceleration and idle. Noise goes away when gas pedal is pressed.

Checked manifold bolts - found 2 that needed tightening but did not fix the problem.

[moestoy]

Intake gasket leak?

Possibly, trying to rule other things out before pulling it all apart.

[brokenujoint]

Possibly, trying to rule other things out before pulling it all apart.

pretty overlooked item

[alittleoff]

When I hear whining it's usually my wife.
Sorry, someone was going to say it.

[inVERt'D]

Possibly, trying to rule other things out before pulling it all apart.

Spray some carburetor cleaner or WD-40 around the gasket areas while it's running. If there's an intake leak, it will change the way it runs when you spray it. Check all the vacuum hoses and fittings.

[brokenujoint]

Just bought a "new to me" '97 Jeep Wrangler SE; 2.5L 4 cyl.

On the way home it started making a whistling/whining noise. Test drove for about 30-45 minutes with no problems. Now as soon as it gets to temp (approx 5 minutes or less) it starts. Does not matter if AC is on or not.

Please help. :confused:

On a serious note. Sometimes my 97 tj (although a 4.0) would whistle too. It was from the throttle body. There is a machined square hole in the TB that can sometimes cause that. Mine happened when I cleaned it with some TB cleaner, Maybe check it out and possibly VERY mildly file the edge to a slight chamfer.

Could also be a vacuum leak.

Is it a whistle or a whine.. Two different things. Usually you whistle at them.. then after awhile (shortly) they whine. Mine usually moan...

[inVERt'D]

Spray around the throttle body butterfly valve shaft too.

[Mike]

Starts when engine gets hot, noise only on deceleration and idle. Noise goes away when gas pedal is pressed.

Checked manifold bolts - found 2 that needed tightening but did not fix the problem.

I am assuming that you have an automatic transmission then? The noise on a manual should drop quickly when the clutch is depressed. This might be helpful to know...

[brokenujoint]

do this.. While driving about 10 mph lightly tap on the throttle just enough to make it happen. Then take your foot off the gas. play with it a few times. if it comes and goes its in your TB...., either manifold, or your exhaust ... what whistles? AIR...... if you still cant isolate it, get some soapy water, disconnect your fan.. (PITA) if its mechanical clutch type. and run your motor. then spray the water around your head to manifold, .. if you see bubbles or your engine starts sputtering or both, you've got a leak. . You can also put a shop vac to your tail pipe and feel for it coming out anywhere. You should SHOULD.. that is,,, have an open exhaust and intake valve so the air will escape through the intake... hope this helps.

[NAILER341]

Is there a throttle body spacer? Those can whistle.

[Ol Man]

Where's Moe?

[RAT]

Where's Moe?

In the White House... ;(