Isuzu 3.2 vs 3.5

[TwoTrack]

I have been doing some research on both the Trooper and Rodeo and have read in multiple places about the Intake Manifold Gaskets and eventual block failure on the 3.5. Are these exaggerated issues?

Occasional problems on this vehicle are failure of the Intake Manifold Gaskets and the Engine Short Block. Failure of the Intake Manifold Gaskets may cause a rough idle or the Check Engine Light to illuminate. Lack of maintenance can cause the pistons rings to stick resulting in excessive engine oil usage. This engine oil usage can lead to piston rod bearing failure resulting in replacement of the Short Block.

Does the 3.2 experience the same type issues?

Both vehicles look very capable with few mods. And other than the above issue seem to be easily maintained. I am needing something with more passenger space and the Trooper has really grabbed my attention.

Thanks for any help or advice you can give.

 

[TRegasaurus]

I have a '99 Isuzu Rodeo with the 3.2 V6 and after 160k the engine is fine. No smoke, passes smog, no leaks of any kind. My only issue today is a possible bad starter. I'll take care of that this weekend.

 

[TwoTrack]

So after doing some more research I found planetisuzoo.com. Great place. But they have hundreds of threads of the 3.5L dying before it barely makes it to 60k due to oil consumption.

 

[AFSOC]

It's very well documented that the 3.2 and 3.5 Isuzus are ravenous consumers of oil. In my research the issue seems to be worse with the 3.2l engines. Several years ago I contemplated a buying a Trooper. I liked the way they drove and the interior space but just couldn't find a good truck that hadn't already started burning oil. To compound that issue the lack of dealer support network just made Trooper ownership too great a risk. If your heart is on an Isuzu, just rationalize its shortcomings with the old Rover adage: "It's fine if you keep up with the PMs"

 

[BigSwede]

I doubt if there are hundreds of threads (I am a regular over there), but from 98 to sometime in 2001 the 3.2/3.5L motors didn't have adequate drain-back holes on the piston oil rings. The motors with the fixed oil ring design can be identified by a screw-in PCV valve, as opposed to a push-in design. This design flaw sometimes cause the motors to burn oil quickly and fry the motor when the level got too low.

That said, there are plenty of those motors doing just fine. I have a friend with a 2000 Trooper, no problems with oil burning.

The intake manifold gasket has been a fairly common problem. I used to have a 99 Trooper and the IMG went out twice. The good news is that it is not a serious problem, does not disable the vehicle or harm the engine.

The older 92-97 3.2L V6s are very reliable motors, no particular oil burning issues.

 

[TwoTrack]

So you're saying that the 2002+ engines are not going to burn oil? I like the looks of these but one of my main goals is to get something that is going to be reliable.

 

[double moo]

My '93 3.2 has 188,000 miles and doesn't burn any noticeable amount of oil. From oil change to oil change i never have to add anything.

As for reliability - I still head out on 1,000 mile trips without hesitation. I bought it new 18-1/2 years ago and still trust it whole heartedly. Maybe I'm too trusting?

 

[BigSwede]

Not at all, I drive my 93 Trooper from Minnesota to Moab, Utah every year, ~1,300 miles one way, wheel it for a week or so, and drive back. Mine doesn't burn any oil either, 139K miles.

 

[BigSwede]

So you're saying that the 2002+ engines are not going to burn oil?

Well individual results may vary as always, but mid 2001 and newer have the fix.

Of course, no Troopers were imported after 2002.

FWIW my 99 did not burn any oil when it was totaled by a doofus running a red light...it had 65K at that time. I was t-boned by an Exploder at 50 mph...walked away without a scratch.

 

[TwoTrack]

Of course, no Troopers were imported after 2002.

Good to know. It looks as though for reliability sake I need a pre-97 3.2L.

 

[stomis]

I have a 94 w/a 3.2 SOHC and 187,000 on the clock. I bought it about a month and a half ago. I changed the oil when I got it and have noticed the thing is thirsty for a half a quart every 800miles or so. Honestly thats not terrible. It doesnt smoke and runs perfectly fine, has good power still etc.

The only other inherent problem with the early 3.2s is the lifts gumming up. Its a symptom of a combo of poor maintenance and bad design.

Personally when I go to rebuild the motor in the truck Ill be retro-fitting a later 3.5 crank and pistons into the early 3.2 block for a little more oomph.

 

[BigSwede]

The only other inherent problem with the early 3.2s is the lifts gumming up. Its a symptom of a combo of poor maintenance and bad design.

The 92-97 SOHC 3.2L had hydraulic lifters, the 92-95 DOHC 3.2L did not. And the lifter tick is not really a significant problem, just annoying.

 

[BigSwede]

Personally when I go to rebuild the motor in the truck Ill be retro-fitting a later 3.5 crank and pistons into the early 3.2 block for a little more oomph.

It would be easier to swap in the DOHC heads and intake...gain you a quick 15 hp. The DOHC was rated 190 hp, the SOHC was 175 hp. Other than heads and intakes they are pretty much the same engine. Of course, this doesn't help if your motor is in bad shape and needs a rebuild.

 

[Maddmatt]

Like others have said, you have to go in with open eyes. I loved my '97 Rodeo. But it got new intake manifold gaskets at 19K (under warranty) and they were starting to seep again when I traded it in at 90k. - there is a lot about that truck that I miss though, in hindsight it was a good fit for me.

 

[cronk]

I can testify that with proper maintenance, the 3.2 will last a long time. Mine has been going 10 years and is getting close to 150k. It does use a little oil between changes due to the ring flaw but I check it often out of habit. For maintenance though the years, I have changed the timing belt, water pump and intake gasket along with the coolant cross pipe o rings. The only task I had to do was the cross pipe o rings because they started to leak, kinda had to do the intake gasket with it. Did the others as preventative maintenance. Nothing was too terribly difficult to do, hardest being getting the timing set up right when I did the timing belt change.

If you go looking for an Isuzu, look for a southern truck with low miles. You can still find plenty on the net for very reasonable prices.