Best oil for an Isuzu 3.5L that burns oil

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Jharris1385

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As the title states, I burn a lot of oil in my 3.5L Isuzu.

The issue is, the drainback holes in the heads get clogged and in a shortened version, owners burn oil. Outside of piston head work, what do you think is the best oil to clean?

I burn a quart every 500 or so now, maybe more.

I have heard and used diesel oil (supposedly higher detergent rating), Marvel Mystery, Lucas oil, etc. But I do have to admit, I probably have not used a single item long enough to take effect. How many changes till you would think i would see results?

I have also seafoamed the oil, vacuum lines, Egr, and gas tank.

Too many owners are having issues as the engines age and blowing up (burning more oil than expected and not checking and driving dry). I drive an Isuzu Vehicross and if you are familiar with it, love it or hate it, its rare and like your favorite auto, you dont want to see it go.

I live in Southern Indiana for viscosity reference.

Thank you in advance, as this is my first post.
(However, I am a recent GC user in my other auto, gold not green, via Amazon)
 
JHarris, I used to be very active in all that was Isuzu back when I owned my 2002 Isuzu Rodeo 3.2 and we had several other Rodeos and Troopers of that vintage in the family. It's not drain-back holes in the cylinder heads, it's drainback holes in the pistons (oil control ring land) that was the suspected issue.

These 3.2/3.5s were tanks provided you don't run them low on oil, they have a tendency to spin the #1 connecting rod bearing that being the case (pretty sure it was #1.. been awhile!).

You can go right up to 15w40 motor oil and these V6s will purr along happily. That's what I would run if it's a real bad consumer of oil. Get the least expensive fleet 15w40 you can find and use that.

The Vehicross is a cool rare beast. Way ahead of it's time in terms of looks. Look how many SUVs either look like it or the Axiom today.
 
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Is pulling the valve cover off and spraying it all down with brake cleaner possible? Probably better than changing the oil 6 times and it not really do much. I'll let the others decide if that's a dumb idea or not. I'd just make sure you pour oil back onto the moving parts so they aren't dry when you crank her back up.
 
It probably won't clean, ever.

Drive it. Top off oil at every fillup.
Change oil and filter every 7500 miles. Use M1HM 10w40. Topping off can be expensive so use whatever cheap oil you want(like Supertech or Napa), or 15w40.
 
Ive had good success with using GM top end cleaner to clean & free up the rings & oil drain holes in the #3 ring land area. Pull the spark plugs & pour in about 1oz & let it soak for 4 hours. Pour in some more & turn the crank every couple hours to work it into the rings. Crank with the plugs removed to blow out all the cleaner & reinstall the spark plugs. Drive the car for a couple days & repeat the process. My car doesn't smoke like it used to & oil consumption is down from 1 quart to almost nothing in 3000 miles. Here's the GM cleaner I used. http://www.amazon.com/ACDelco-X66P-Injector-Engine-Cleaner/dp/B0013FMW84/ref=pd_sim_263_1/181-7665374-7217240?ie=UTF8&dpID=41538K9fzLL&dpSrc=sims&preST=_AC_UL160_SR160%2C160_&refRID=04500052YZDM74WF1EJ0
 
Back when I participated heavily with this make/model Isuzu, some owners did have some luck doing a piston soak through the sparkplug holes, but it wasn't a permanent fix. Oil burning aside, these were a tank of an engine. A little odd and large looking with the 80deg "V", but they were smooth and powerful.
 
Originally Posted By: JTK
it wasn't a permanent fix.


If you're actually going to try and address issues with this engine, the kids gloves (MMO, Lucas, ARX, cheap piston soak, etc.) need to come off, and you have to get serious about it...

Two part solution:

1. Clean deposit formation.
2. Stop the problem from recurring.

As to #1, http://www.kanolabs.com/engCle.html (Kreen). It's not cheap ($60/gallon), but the best product in this situation.

For #2, you'll need to select the proper oil (and be willing to pay a few $ more).
 
Hello from a fellow Hoosier!

We own a 2001 Trooper with the 3.5L engine. We bought it brand new and maintained it over the years. We first used Amsoil for the eight years or so, then moved on to different oils. Tried Delo, Rotella, and then lastly Delvac oils. Used these oils because I read on the Isuzu forums the high detergents was good for the oil drain holes. Also, we use the Trooper to go to the farmers' market so I wanted the extra antiwear. It has consumed a steady amount of oil over the years, even with the diesel oils, I just had to keep topping it off. I ran an Auto-Rx clean and rinse with Delvac 1300, and it still was consuming a little oil, but a lot less than before. I think it is because the Delvac really helps cut down on comsumption.
Then, I dumped the rinse oil last fall, and put in Delvac 1 5W-40 ESP. I recommend trying this oil. It has all but halted the oil burning.

The good news is that Meijer is now carrying it. When they first started carrying it, they had it priced at $28.99. Then, this spring and summer, they reduced it to $24.99.
 
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Originally Posted By: njohnson
Then, I dumped the rinse oil last fall, and put in Delvac 1 5W-40 ESP. I recommend trying this oil. It has all but halted the oil burning.


AFTER cleaning with Kreen, that would be an excellent choice:


FY4KuF8.png
 
If you KNOW the drain back holes are plugged I would try to open them up with a probe, air pressure or solvent and see what the results are. You may be sucking oil through the seals and valve guides and burning it.
 
Originally Posted By: SLJ2137694
If you KNOW the drain back holes are plugged I would try to open them up with a probe, air pressure or solvent and see what the results are. You may be sucking oil through the seals and valve guides and burning it.


This would require removal of the pistons.
 
My friend had the Acura SLX, same engine. It used a quart about every 600 miles, we tried a few different weights of oil and settled with using Rotella 15W40, it reduced to about a quart every 750 miles. Just keep it topped off, if you like the vehicle. The consumption stayed at that level while he owned it.
 
Originally Posted By: JTK
Originally Posted By: SLJ2137694
If you KNOW the drain back holes are plugged I would try to open them up with a probe, air pressure or solvent and see what the results are. You may be sucking oil through the seals and valve guides and burning it.


This would require removal of the pistons.


Apparently the OP doesn't fully understand the issue, so is confusing the replies...

Originally Posted By: Greasymechtech
It probably won't clean, ever.

Drive it. Top off oil at every fillup.
Change oil and filter every 7500 miles. Use M1HM 10w40. Topping off can be expensive so use whatever cheap oil you want(like Supertech or Napa), or 15w40.

Yeah that makes perfect sense, use a HIGH quality HM oil, then dilute it with something else before it has any chance of helping...

Either use and add the same HM oil(give it 2500 miles or so) or just go straight to the Delo or whatever and keep it topped off...
 
When I said heads, I shouldn't have. I was referring to the head of the piston but I easily see now how that is confusing.


I am currently using Rotella T6

But from the replies here I should change to Del and use a cleaner more powerful than MMoil or etc through the spark plugs.

I appreciate the advice.
 
Delo 400 LE and change it every 5K or so. The added detgergency will help.

To get the top ring free, I'd shoot a goodly shot of Break-Free (gun solvent) into each cylinder. Spin it over w/o starting it and let sit overnight. Break Free is a carbon solvent used to clean gun barrels. It loosens rings real well.

Do this before you do an oil change. Any that gets into the crankcase will come out with the used oil
smile.gif
 
Originally Posted By: Jharris1385
But from the replies here I should change to Del and use a cleaner more powerful than MMoil or etc through the spark plugs.


Kreen and Delvac 1 ESP 5w-40.

Additionally, I'd like to comment on something else: A few different individuals in this thread have recommended 15w-40's. While these are generally robust products that do a fantastic job, you're dealing with a design flaw here that necessitates an oil that's otherwise severely overkill for the application. In the TEOST test, ESP 5w-40 leaves 10mg of deposits.

Rotella T6 leaves 50% more behind.
Delo and Rotella 15w-40 are both 150% higher.
Fleet is up to a ridiculous 300%.
 
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