[radare]

I'm in the middle of this now. I've completely removed the intake manifold and plenum so that I could clean them out.

Here are some observations that I've already come up with.

First, I thoroughly detailed the engine before I remove the manifold, yet, when I remove it, the area around the lower gaskets was still surrounded by dirt and grime. I don't know how you guys can confidently replace the gaskets by simply removing the bolts, lifting the manifold assembly and sliding in the new gaskets.
I did have some small flecks of dust fall from the fuel injector seals and land on the valves when I removed my manifold. A solution of soapy water and a shop vac with it's hose reduced by taping a vacuum hose to the end, worked well to suck out anything that may have fallen into the head. Once you are satisfied that the engine is clean, place masking tape over the cylinder-head openings to prevent anything from falling in there. Give the top side of the engine a good cleaning in preparation for reinstallation of the manifold.

Second, looking at the throttle body and plenum gaskets, they were dry and nasty. I wouldn't want to do this job without replacing them as well. My lower gaskets were cracked enough that small bits and pieces fell out on removal. Make sure these don't fall in the engine.

Third, the inside of my manifold (on a truck with ~73k miles) was totally nasty; it is filled with oil residue and chunky carbon deposits, likely from the poor EGR design. Now is a good time to carefully clean this crap out.

Fourth, as they are relatively inexpensive, replace the injector o-rings and the thermostat while you have the manifold removed (since you will have to remove the manifold to replace the thermostat when you do it anyway). The aftermarket part number for the o-ring set is C1060-104168 and it is made by Nippon Reinz and runs about $20. The part number for the stock injector o-ring set is 8171134000 and runs between $15 and $23, depending on which dealership you buy it from.

Finally, the throttle body gasket from Checker (or Advance Auto) is wrong. The package shows it for a 1993 to 1995 Rodeo, but they sell it for all years. Don't buy it. Instead, get a roll of gasket material and cut your own.

A list of parts that would be good to have on hand, if you remove your manifold for any reason, are as follows:

Lower manifold gasket set (2 gaskets) ($32.84)
Plenum gasket ($7.63)
Throttle body gasket (make this yourself)
EGR Valve Gasket ($5.97)
Injector o-ring set (PN 8171134000) ($13.48)
Thermostat and seal ($14.48)

I purchased these parts from isuzuparts.com (Scarff Auto in WV) for the prices listed above. The Isuzu parts are actually cheaper than the aftermarket version at Checker/Advanced Auto.

Hope this helps someone elses IMG replacment move a bit more quickly.

 

[radare]

Here are some follow-up images from the process:

The engine with the entire manifold removed; it has sat like this for a week while I wait for parts to arrive (and will sit another week at least):

Here is a shot of the plenum after removal. I blame the EGR design for all the nastyness inside this thing. The plenum-to-manifold gasket was definately ready to be replaced: (Who here knew that the 2nd gen Rodeos had dual length runners?)

And a nasty shot of the plenum after removal. Yuck:

Finally, shots of both parts above, cleaned and ready for reinstall:

I'm doing the timing belt at the same time; the old girl is getting a full IMG and throttle body gasket replacement, new injector o-rings, timing belt, tensioner and pulleys, cam seals, crank seal, waterpump and thermostat and she's just at 79k now.

 

[marcre]

nice looking job, real nice pictures too. I wish I had the ability to do that to mine.

marc

 

[radare]

It's not too tough of a job; took me 2 hours to pull it off.

I then cleaned everything up with Castrol Super Clean degreaser. Avoid getting this stuff on your hands as it'll attack your skin like it does grease. Once clean, I typically strip off any corrosion with Eagle One Etching Mag Wheel cleaner, though, I didn't have to do it to this manifold.

 

[Blue]

This is awesome! I'm inspired. I spent sometime looking at my 99 Rodeo wondering about doing this too. I just don't have the experience you do. It would be my first attempt at something like this. I'm pretty good, not a total dufuss around an engine, do you think I could attempt this? Or should I ask an import shop to clean mine out? I've got 113k on my Rodeo and I bet it is a mess. I love this truck and I want to drive it a long time.

 

[radare]

Finished reassembling everything tonight (and then began on the timing belt). Here are a few more notes from the installation.

Starting with the bare engine shown above, add parts in this order:

1. Bolt the fuel line bracket to the rear of the lower manifold and then bolt the manifold in place. Leave the tape over the intake ports until the last possible second as to prevent dirt entering the engine. Bolt the lower manifold in place, tightening the nuts hand tight.

2. Bolt the upper intake manifold to the lower manifold. Spray the gasket with Permatex Gasket Adhesive and tighten the bolts in a criss-cross patern, including the mount bolts and the plenum bolts. Leave the vacuum valve bracket off of the upper manifold for now (you will bolt it in place later)

3. Install the fuel rail; place new o-rings on the injectors and lubricate with engine oil. Attach the fuel lines to the rails and then lever them in place. Press the injectors into position and bolt.

4. Install the EGR lower tube and then the valve; use a new gasket.

5. Attach all remaining wires and hoses.

Be sure to keep any open ports covered with masking tape until fully installed. This will keep gunk out of the engine.

 

[timrkopi]

What happened to the pictures. Sure just when I need to see them
they disappear

 

[Amigo-2k]

http://isuzufaq.ibctech.ca/inside.pdf

 

[Dcm15423]

Hello
Did you use any kind of sealer when replacing the Lower manifold gasket?
I just bought the Fel-pro manifold gasket set and i never seen any kind of gaskets like the Lower manifold gaskets...

 

[radare]

Sorry guys; didn't realize the pictures weren't loading. I've switched everything over to my new website (http://www.900saab.com) and they all seem to show now. Let me know if there are any problems.

 

[MarcusInMD]

Did cleaning the inside of the manifold help with performance/oil burning etc?

I was looking at the EGR tube design and wondering if that 90 degree turn at the back of the engine can even be cleaned correctly without tearing everything out like you did. My EGR tube was a mess and I am wondering if that turn might still be really clogged up.

 

[radare]

Did cleaning the inside of the manifold help with performance/oil burning etc?

I was looking at the EGR tube design and wondering if that 90 degree turn at the back of the engine can even be cleaned correctly without tearing everything out like you did. My EGR tube was a mess and I am wondering if that turn might still be really clogged up.

I didn't see any changes in oil consumption after the cleaning. I did see an improvement in idle quality and fuel mileage, though.

 

[jimmyc]

Radare, thanks for posting this, especially with the great pictures!

I'm thinking my intake manifold gasket(s) is gone...had one replaced already on my '02 Rodoe, and think it has happened again. I had three replaced on my '99. The local shop has been getting more expensive on this repair so I am thinking of attempting it myself. Could you reply with an answer to the question asked by "Blue" above...I think I'm in his position, have done brake jobs and tuneups, etc. How much more involved is this? Seems like a fairly straightforward, unbolt everything carefully and then rebolt. Is that the case?

Btw, how exactly do you know your intake manifold gasket is gone? Did you read an ODB sensor?

Thanks very much.
-Jim

 

[bsmart10]

when you took the fuel rail off the top of the plenum, did you separate the injectors at the top from the fuel rail, or did you remove them as an assembly, and separate them later? How does the fuel rail come apart on the back-side? Do you have any other pics that show that part of the dis-assembly?
How did you de-pressurize the fuel system before taking the rail apart?

thanks

 

[bsmart10]

Well I found out today that the connectors are a bit tricky to remove from the top of the injectors. There is a little light blue tab on the top of the connector that has to be carefully pryed up about 1/4" to allow you to pinch the small black center piece on the opposite side that releases the connector. It takes care and patience to do it safely, but it can be done.

I had more trouble getting the rubber fuel hose off the rail inlet on the passenger side than with anything else. I think it was glued to the pipe. I had to dig it off with a screwdrive and hammer it off with a mallet. It looked pretty bad by the time I got it to release. The opposite side came off without a hitch, but its in a bad tight spot under that vacuum switch bracket. Nasty little spot to work under. I couldn't get the fuel rail off without bending it, oops. But it all came apart, went back together after replacing the plenum gasket, and it looks like there are NO fuel leaks. Whew!!
And, there is no more vacuum leak hiss, and the CEL light is out. Not to mention, the Troop seems to be more responsive to the accelerator now.

 

[bsmart10]

Let us know about the fuel hose. Did it have enough slack to lift the intake without removing the hoses? From the 'Hall of Fame' pics, it looks like there's a Y connector that bolts to the back of the manifold. It also looks like the manifold will have to be lifted a couple of inches to clear the 4 corner bolts, so the gasket can be removed and the new gaskets installed. If you can do it without removing the fuel rail, it will be a whole lot easier to re-assemble. I had the most trouble getting the fuel rail off around that bracket on the drivers side near the firewall. The trick I used was loosening the back bolt on the bracket and tilting the bracket toward the passenger side so the regulator would clear. Its a very small space between the bracket and the firewall and I had to use a stubby hex wrench to reach it. I bet that is what you were referring to in your post here. Really a tricky spot, and that's when I bent the fuel rail assembly tube. Thankfully it went back together OK and after I replace the o-rings, i saw no leaks anywhere.

 

[bsmart10]

The other trick was putting the plenum top back on after the new gasket was installed, because the vacuum actuator on the back side of the plenum was an obstruction. I had to 'slip' the top in at an angle from the drivers side, toward the passenger side. Tricky and tedious to prevent gasket damage, but it worked.

 

[pktrusty]

I know this maybe a silly question. But what is mounted to your intake near the firewall on top? It almost looks like a filter but I know it is electronic. I dont have this on my trooper.

 

[jimmyc]

If this is what you mean, then this is the EGR.

 

[jimmyc]

Just wanted to add I found the RockAuto website http://www.rockauto.com much better than isuzuparts.com. The parts were a little less expensive and the shipping much less expensive also.

Going to attempt this as soon as the parts come in.... :wink: