"Just throwing my oil-ring into this fire".

I have always owned at least one Isuzu trooper since 1984 sometimes several
have been in my driveway. Today I own a new 2005 Ascender 4.2L  (GM 291
horse pwr version)  uses absolutely no oil ever. I use Mobil One Syn and
change it typcially every 7500 miles with the best Purolator filter.  Mobil
says that I can run it to 15,000 miles.  I have never been that daring to
keep it in the crankcase to 15k.  Does anyone here know if  driving it for
15k is possible or adviseable?

Also I have a 1990 Trooper with the gas  2.6L fuel injected model with 166k
miles and has never shown oil loss below the dipstick full mark.  I use a
high grade of 10W40 and very inexpensive from Advance Auto Stores

I recently sold my 1996 Trooper 3.2L gasser that routinely consumed 1 quart
approximately every 750 miles.  But this 96 really ran super.  I hated to
get rid of it and miss it alot.  Maybe that 3.2 eng craved the adding of oil
that would therefore reward me by running so well if I gave in to it's
drinking habit, LOL!.  I bought it new and did all the maint intervals to
the letter.  If it had not been for the oil useage I believe that I would
not have traded it in to the Ascender.   But now that we drive the Ascender
both my wife and I agree that it is the finest car, truck, SUV that we have
ever had the pleasure of driving/owning.

I just cannot get the Isuzu bug out of my system.  "In for a dollar - In for
a hundred"

Ernie -  Fort Bragg, North Carolina, USA

Joe, I misspoke when I said that and I was wrong. I had read anecdotal posts
from several people that said exactly that, but as an owner, they have never
officially admitted that they have an oil consumption problem or that their
engines are built wrong to me in some or any kind of  formal communication.
So, if your question is in Isuzu's admission of guilt of their engines being
built wrong and having excessive oil consumption, I stand corrected.

However, I will say unequivocally, as an engineer and a mechanic, that there
is a fundamental flaw in either the construction or design of the 3.5L
engines in that the oil use is excessive, more than I or anyone I've ever
done work for would tolerate. 300 miles to the quart is simply unacceptable.
The dealer in Colorado Springs, CO was the one who alerted me to the problem
of them being "thirsty" at highway speeds - I didn't mind the 1 quart every
1500 miles, but when I had to put a quart in every 2nd gas fill, then I
confirmed that there's a serious problem here. And I change my oil
regularly, with a high grade, multi-vis oil.

So, do you agree that the 98-01/02 3.5L engines have a problem and that they
were changed (In 2002, I believe... may have been 2001) to correct that
problem?
And if you don't, then why do they consume so much oil?

Steve

Try using 15W40 oil (that's what Isuzu dealer recommends I use)

I wondered the same thing, and finally realized that my catalytic converters
are plugged. I'm pretty sure that all that oil has caked up the matrix and I
need to do something drastic. I'm going to do a couple of things and I'll
report back on what the results were.
r/
Steve