Jim Grant's Tech Tips
'00 Isuzu Trooper, Engine Whistle
My '00 Isuzu Trooper
LS recently developed a loud ear piercing whistle sound coming from the
engine. It is not the serpentine belt. The sound goes away when the truck
is in drive and the accelerator pedal is depressed then comes back when
I take my foot off the gas. I'm lost. Any help?
I'll bet a coffee you
have a vacuum leak. With a piece of heater or vacuum hose to your ear
move the other end of the hose around the engine while it is running (whistling).
This will allow you to locate the source of the whistle. In most cases
we've found the vacuum leak to be on the left side rear of the engine
at the intake manifold to cylinder head. When the gasket lets go it creates
this amazing whistling noise. If I'm right a new intake manifold gasket
will be the fix. If I'm not, it'll still be a vacuum leak and some sort
of gasket/seal failure involving the intake manifold.