Hiss/Whistle in 03-4.0L TJ
 

Guys and Gals,

This is my 4th TJ to own and all of which are 4.0L.

Now this is also my first 4.0L to whistle around 1700-2300 under load(normal
driving conditions).

I can actuate the "hiss/whistle" by pressing slightly on the accelerator,
any speed, just again at 17-2300. The engine does not necessarily have to
increase in RPM's, but more air/gas is flowing into the engine.

Any thoughts?

Thanks,
P

Re: Hiss/Whistle in 03-4.0L TJ
 

Interesting....Thanks...I'll start out looking there...I was thinking almost
obstruction in intake or gasket issue..........Done it since day one, and no
codes, but I'm going to check all of the lines. Just a hassle to take it to
the dealer....

Thanks for the thoughts.

Patrick

"Jeff Scherb" <jscherb@wideopenwest.com> wrote in message
news:2iGdnTFnj7wmuZWiXTWJkg@wideopenwest.com...
> I have the same thing in my 95 YJ; I assume it's a vaccum leak somewhere
but
> I haven't been able to find it...
>
> "Loft-o-Turn" <turnerloft@sbcglobal.net> wrote in message
> news:cisNa.607$l_5.374273140@newssvr12.news.prodig y.com...
> > Guys and Gals,
> >
> > This is my 4th TJ to own and all of which are 4.0L.
> >
> > Now this is also my first 4.0L to whistle around 1700-2300 under
> load(normal
> > driving conditions).
> >
> > I can actuate the "hiss/whistle" by pressing slightly on the
accelerator,
> > any speed, just again at 17-2300. The engine does not necessarily have
to
> > increase in RPM's, but more air/gas is flowing into the engine.
> >
> > Any thoughts?
> >
> > Thanks,
> > P
> >
> >
>
>
>

Re: Hiss/Whistle in 03-4.0L TJ
 

Loft-o-Turn wrote:
> Interesting....Thanks...I'll start out looking there...I was thinking almost
> obstruction in intake or gasket issue..........Done it since day one, and no
> codes, but I'm going to check all of the lines. Just a hassle to take it to
> the dealer....

Clean the throttle body and idle air passage.
http://members.cox.net/wilsond/tb/tb.html

Here is the clue
"I can actuate the "hiss/whistle" by pressing
slightly on the accelerator"

That's intake whistle. Don't have one of those airswirlythingys on
there? That's the only thing they do well.. Make noise that is. ;)

To check for leaks:
Start engine
Spray some TB cleaner around the base of the TB, and intake rail, hoses, etc.
(just keep it off the paint)

If the engine stammers you have found the leak.

If the leak is from the TB base. Do not (DO NOT) crank on the bolts to
tighten it down, that will only warp the base. You will need to check
the base for level, resand if not flat, and put in a new gasket.
Bolts only go to 9 ft.lbs.

The backyard fix for a TB that isn't flat. Start with 200 grit sandpaper and
a flat surface (countertop etc) set the paper down and do a figure 8 with the
tb on the paper.. switch to 400 then 800 as it gets flat. Can't do this too many
times.


--
-- DougW -- 93 ZJ 4.0 http://members.cox.net/wilsond
HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks
Gibson Exhaust - rear DCpower - custom gauge install - Stillen Rotors