http://www.geocities.com/endre_rl/isuzufaq.htm#faq5
I hear an air leak sound while the engine is running and my engine runs ruff, what could it be? Intake manifold gasket leaking: (P0300).
Do you have a Rough idle, check engine light on, or air leak noise from under the hood. The Intake gasket breaking may be the cause on the 98 and newer v/6 Trooper and Rodeo.
Surging, stalling and system lean bank codes points towards a bad intake manifold gasket.
You may also hear whistling sound that goes away after a couple of weeks. It goes away after the hole in the gasket gets bigger.
http://www.planetisuzoo.com/articles.htm/15
Stalling / TSB about a leaky intake manifold gasket. Presents itself as a sporadic stalling problem under the following conditions: a. Engine at normal operating temp. b. Low speed or acceleration from a stop. c. 15-20 seconds before shut down, engine feels sluggish like missing fuel. d. The engine stalls and is hard to start but after 3-5 minutes of rest it does perfectly fine and engine runs smoothly. Solution 1: Check computer and reset/check PCM wires. Solution 2: Dealership says most of the 3.2L's they checked for a leaky gasket turned out to have it.
Isuzu P/N: 8-97237-538-0 list for $18.88 ea
This message was from Sam Jelinek, who many of you know from ZuZoo and elsewhere. He is an Isuzu Master Mechanic
I believe, and in this message he described how to replace an intake manifold gasket on the 3.2/3.5 engine.
Please note that I have not tried this procedure, and cannot say if and how well it works. I offer it simply because many of us with Isuzu V6 engines are getting out of warranty now, and may need DIY instructions.
So here it is, paraphrased and edited for clarity (Sam is a better mechanic than writer):
Quote: ---------------------------------------------------------------------------------
Something that has been showing up even more lately on the new V6 engine, the intake gaskets are starting to leak and break. If the gasket is leaking real bad you can hear an air leak from the engine, almost like the airbox is not tight.
Using a can of brake cleaner you can check this very easy. Spray around the intake, most of the time on the drivers side, and you can find the leak.
To repair the leak, here is how it goes:
Remove the air intake hose from the throttle body.
Remove the 4 bolts that hold the throttle body to the intake. No need to remove any other hoses from the throttle body.
Unhook the injector wiring from each injector.
This is the hard part: on the passenger side of the intake you have to remove the EGR flow pipe nut. You will need a 7/8" or 22mm wrench, may even have to cut the wrench short to get it in there.
Remove the 2 long bolts on each side.
Remove the 2 short bolts from each side, I think they are on the front and rear of the intake.
On the Troopers the intake will lift up enough to get the old gaskets out. On the Rodeo use short bungy cords to hold the intake up so that the old gaskets can be removed.
When removing the old gaskets be careful, they may be broken. Do not let the pieces fall into the intake.
Use a clean rag to wipe off the intake surface on the cylinder head and reinstall the new gaskets.
Let the intake back down and start the EGR flow pipe before putting the other bolts in the intake.
Reinstall the other bolts and air intake hose.
http://www.4x4wire.com/forums/showflat. ... Post474461