My Disco makes an awful whistling noise in gear at idle. Thinking it was a vacuum leak, I've replaced many of the vacuum lines, each time thinking Ah Ha, that's the culprit. No dice.

Defender-stumbles when electrical ancillaries are turned on. Ground or poor alternator?

Anybody got any suggestions?

Thanx,
Paul

Originally posted by PTSchram
My Disco makes an awful whistling noise in gear at idle.
Defender-stumbles when electrical ancillaries are turned on. Ground or poor alternator?

Anybody got any suggestions?

Thanx,
Paul

Uh....Were is the whistle coming from? If it happens in gear at idle then why can't you pin-point it? Might be (in) the MAS or even the plenum...If it's 'awful' then you sould be able to issolate right?

Stumbles? How many 'electrical ancillaries' are you running? Those DC micro-waves wreak havoc on a 90amp alt and weak battery!

Try a Optima yellow top, and check your alt...However I'm sure it's just dragging down trying to power up all of your 'ancillaries'.

--D

For the whislte, I've tried such things as the old "Hold a piece of heater hose up to your ear and poke aournd with theother end", but al I can hear is the noise from the internal sof the engine (valve train, injectors, etc.). It almost sounds as though it could be coming from the front end of the engine, but it seems to be loudest on the left side, beneath the air intake.

Ancillaries: Air conditioning, radio, lighter.

Paul

Exhaust manifold leak ?

Is it a pre-96 3.9 or GEMS 4.0 block ? I think the older engines had a habit of leaking at the front of the manifolds.

The ones I've heard could be described as a 'whistle'. Off idle, the engine makes too much noise to hear clearly.

keith
:usa:

Originally posted by PTSchram
It almost sounds as though it could be coming from the front end of the engine, but it seems to be loudest on the left side, beneath the air intake.

yeah - that's where you'd hear it the loudest if it was leaking on the drivers side...

keith
:usa:

Originally posted by PTSchram

Ancillaries: Air conditioning, radio, lighter.

Paul

Well...Can'help ya' with the whistle, but your ac comp is what's bogging down the 3.9. Does it studder w/o the ac on?

The Disco is a 3.9 Serpentine.

OK, I'll check the exhaust manifold for leaks, but why would it only do it in gear and go away at idle. I'll also pull the MAF off and look for anything out of the ordinary there.

With the Defender, it stumbles not only with the A/C, but if you push in the lighter, it instantly stumbles...

Thanks guys.

Paul

Maybe it is one of those Dear whistle things that everyone in Colorado has on their vehicle? :flipoff2: The reason you can only hear it at low RPM is that it is covered up by the engine noise later on. Just a thought if the other ideas fail....

Way

P.S. What did you ever decide on the axle swap??? This was the real reason for the post BTW.