Isuzu SUV Forum banner

Anyone replaced their own intake manifold gasket?

16K views 21 replies 14 participants last post by  HOOS1 
#1 ·
I've done the EGR cleaning, had the fuel pressure regulator replaced and I still experience sputter-starting in the morning. I'm guessing I have bad intake manifold gaskets and am planning to replace them myself?

Has anyone done this themselves and if so, do you have any words of wisdom? Should I buy aftermarket, or do I need to use the Isuzu replacement gaskets?
 
#4 ·
I replaced the IMGs in my '98 Trooper 3.5L engine. It took about 3 hrs. I followed directions someone posted on a website which were much easier than following the Isuzu shop manual which had you disconnecting a buch of stuff you really didn't need to. Overall you need to well organized to make sure you hook up all the vacuum hoses in the proper place.

I would also recommend going with OEM gaskets as the cost is not that significant as compared to the time you will take to replace them.

BTW, before you do all this work spray some carb cleaner around the gasket area itself with the engine running and listen for any idle increase. If you hear an increase it means you have a leak and they should be replaced. If you do not hear any difference you gaskets are likely OK.

Good luck.
 
#5 ·
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
 
#8 ·
Yes, I'm aware. Buying used essentially cuts your warranty in half. Since my manufacture date was 3/21/01 that means the 6 year everything (3 for me) expired in March. That's what I meant by my warranty is over since I bought it used. I still have the powertrain, of course.
 
#12 ·
Yeah, I found that out. Chalk it off to misleading verbiage on Isuzu's website. The freakin' dealer even thought that, although they could've just been trying to slip one by me - they say they've been having trouble collecting from Isuzu for warranty work.
 
#13 ·
I *LOVE* when the dealers use that excuse.

*cue sad violin music*

It's soooo much trouble for us to claim warranty work. It'll take sooo much longer for us to do the repair if we have to claim it under warranty. Do you reeeeeally want to wait that long for your car?

We'll do it really cheap at our "discounted" rate.

At this point I take notes of all the names of the individuals I spoke with and their manager(s). I follow up with a few phone calls to pit a few of corporate types against each other in the regional and main offices. Once I have all their names, and the case numbers and what not, then I write a letter and to be copied to the regional and corporate offices with specific quotes that expose all the contradictions and excuses that they make.

Believe me they'll take care of you in a heartbeat! The corporate offices really hate these types of problems and want to make them go away fast. I use to work in a customer service role and this stuff goes up the chain of command.

It was the only way I was able to get my Intake Manifold fix done without paying $700 when I was at 32K miles. It was also the way I had my catalytic converter replaced under the federal warranty at 78,000 miles after the pipe snapped off my car at the exhaust manifold flange. They wanted me to pay $1000 for that one. Honda only covers Passports for 36K miles or 3 years.

It sucks, but this is the way thir system ends up working.
 
#17 ·
I just replaced my IMGs yesterday and thought I would add my notes here (bold) for anyone that might be new to this.

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. Mine sounded like a whistle or a belt that was slipping, I had that symptom for about a day, then it went away. I didn't experience a rough idle or stall for about a week after that.

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 trickier than it sounds, apaprently you are supposed to pull the blue clip out halfway and then push in the black tab and pull off the connector. I found it easier to reach a finger under the connector and push the tab on the bottom of the connector.

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.
I did hack off the end of a 22mm wrench, it made this much easier.

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.

Missing Step: Remove the four nuts holding the manifold to the block. (one on each corner)

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.
Very helpful to have another set of hands for this!

When removing the old gaskets be careful, they may be broken. Do not let the pieces fall into the intake.
My gaskets were both in several pieces. After pulling the pieces out, I pieced them together to make sure I had everything out. One piece had fallen into the intake, but I was able to get it with a long needlenose.

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.
Be careful with the four bolts that hold on the throttle body, they do not need to be super tight and can strip easily.
 
#18 ·
On the 98+ Isuzu V6 motors, the torque spec for the bolts that hold the intake manifold on is 13 ft-lbs, per the Isuzu TSB (the FSM and likely Chilton's / etc are incorrect and state 18 ft-lbs). The throttle body should be bolted on to the intake manifold at 18 ft-lbs though.
 
#19 ·
the FSM and likely Chilton's / etc are incorrect and state 18 ft-lbs for the Intale manifold gasket torque values
The reason these manuals state 18ft-lbs is because they were changed because of the cracking intake manifolds. Isuzu revised the manifold gaskets and reduced the torque valve to try and keep the gaskets from cracking again.

Joe
 
#22 ·
Great info here. I am doing mine this weekend. I am loosing coolant like crazy. Can't see it, smell it, no water in oil and no steam from exhaust. A Honda tech said the coolant pipes that run under the intake can leak and the coolant burns off fast because of the heat. Having said that I will need to remove fuel lines from the rails and drain coolant. I thought I would pull the fuel pump fuse and let the engine run until all gas is out of the lines. Any thing I need to know before taking the lines off? Any other suggestions would be appreciated.
By the way most of the parts I have purchased lately I have gotten from a Honda dealer. Go to myisuzuparts.com, get the part number and give them a call.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top