Paul Singh wrote:

> "maxpower" > wrote in message
> ...
>
>>it could be a broken intake gasket, if it is a vacuum leak, take a runner
>>hose to your ear and use it as a stethoscope to locate the leak, or at
>>lease
>>eliminate that possibility
>>
>>
> In between I have cleaned the throttle body, air plennum and fuel
> injectors( new O rings). All the gaskets were
> replaced with the new and the bolts were tightened to the FRM specified
> torques. Lot of black stuff I removed. The whistle was there before and
> still is. I cleaned the intake area because I have never cleaned it in over
> 12 years. So I suspect that is not the cause. Last night I looked at it
> again but nothing positive to report about. I think it may help if I explain
> the symptoms a little more.
>
> a) The whistle only comes when the Engine is at operating temps.
> b) If I come home and sit there for couple of minutes without turning the
> engine off, no whistle.
> c) If I let it idle for few more minutes, whistle yes. If I rev it, it goes
> away. Let it idle, it will come back.
> d) Driving normally, no whistle.
> e) While idling if the radiator fan comes on, whistle goes away. It comes
> back as soon as the fan stops.
> f) I removed the PCV valve suction pipe and put my finger on the PCV valve
> to seal the suction. Nope it didn;t help. I can remove the PCV valve
> completely and then see if the whistle goes away.
>
> Lately I also replaced the thermostat because of the engine code. The
> thermostat I bought is not made by chrysler but got it from Schucks which I
> think is made by prestone. Come to think of it, the whistle was there prior
> to replacing the thermostat.
>
> I tried to locate the vacuum leak. No luck yet. While the engine is running
> I tried removing one vacuum pipe at a time to see if that makes any
> difference. No luck. Well, I haven't tried all of them yet.
>
> The fan belts seem to have proper tension, auto tensioner is free to move
> and has good tension to keep the belt tight. The compressor belt has enough
> tension. I have tried different levels of tension on the compressor belt. I
> would suspect the pulleys if the whistle is there all the time. If I start
> the engine cold, no whistle. It starts suddenly when the temp is about to
> reach the operating level.
>
> Can it be ignition timing related at all ?
>
> Bloody hell, I can't even pin point where the whistle is coming from. I
> asked my wife to help me locate the area it may be coming from. She seems to
> think it is from the left side of the engine i.e. the surpentine belt area.
> It is getting to be a challenge now.
>
> I will try your runner hose method and will report.
>
> -Paul

The noise coming on just as it reaches operating temp, and the fans
being on or not affecting it - what shape is the coolant pressure cap in
(i.e., does it need replacing?)? Also, the fans coming on could simply
be changing engine operation enough to cause the noise to stop by
loading the alternator.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
adddress with the letter 'x')