If the oil consumption is due to a propensity for ring deposits, then Auto-Rx can help reduce it. If it's a design characteristic, then there's not much to be done. Some engines use lower tension rings and this appears to result in routine consumption that defies remedy.
While not thoroughly familiar with this engine, I do understand that consumption is a frequent complaint with them. I will have to assume that these engines didn't consume oil at this rate from new. I'll also speculate that, like most more modern engines, they're not really subject to undue wear. A truly worn engine is very rare.
I would first ask if the consumption is linear. While you report 1 quart/1000 miles, is it a flat rate for the entire OCI, or does it have no consumption for so many miles then start to consume oil? If there's a pause before routine consumption, it tends to point to a fatigue factor in the oil. If it's flat/linear consumption, then it points to a fixed/static mechanical condition. Now these two concepts can and will somewhat mesh a bit. An oil can, perhaps, compensate for a given mechanical status until some components fatigue, but for the moment we'll consider them separately.
I would first assure that the PCV system is intact and fully functional. This is ultimately where your oil is going unless there's leaking valve seals/loose valve guides.
Some users have had good results with Rotella T synthetic 5w-40 in these engines. It's reasonably priced at WallMart @ about $20 gallon. It should be suitable for just about any application for 6months regardless of mileage on the higher end. This should not be short trip use in your case, otherwise it would be hard to detect oil consumption at the given rate. This oil is suitable for colder climates except perhaps those that are most extreme. It will still work well enough in sub zero temps, but may not be ideal.
If conventional oil is preferred, I would recommend against HM (high mileage) oils. While they're just a tad higher in viscosity (which you may find beneficial), they contain seal conditioning/swelling agents that are unnecessary if the seals are cleaned and not seeping/leaking. If you're in warmer climates, I'd consider monograde oils SAE 30. They may prove to be harder to find, so 10w-30 would be my next recommendation. If your climate is not too severe, a 15w-40 mixed fleet oil might ease your consumption. The 10w-30 variety of these HDEO (heavy duty engine oils) oils are becoming more widely available at outlets like WallMart. They're also available at Farm/Fleet and TSC.
First - this information is a combination of what I found on the internet and my experience applying it to my 2002 Isuzu Trooper.I had help so I'm passing it on
Everything in the above post is accurate based on what I found as well...
I will add some thoughts...
In addition to the PCV value, look at the EGR valve and how it works. The EGR valve allows exhaust gases back into the intake and helps lower combustion temp.Isuzu seems to have an issue here because the EGR clogs then the temps go up which causes the rings to have build up (maybe that is the case with all engines, I'm not an expert) great news for Isuzus owners is that Auto-RX has a solution when that happens.
When the EGR valve does not work or is clogged, the top of the piston heats up and starts to cook the oil around the piston rings. This clogs the oil ports in the piston and also causes the piston ring to stick to the piston.
Isuzu owners manual says nothing about this very important topic. Clean your EGR valve and flow port every 25,000 miles. Shop wanted to put a new EGR valve on which would have cost over 300.00. I found out it was not hard at all to clean. Couple of dollars and a little time and all was good with that part of the problem.
The way I cleaned the port is with NAPA O2 sensor safe carbon cleaner but again once you clean it the rings are still stuck.I'm new to the Auto-RX forum so if they have a solution for cleaning the EGR Value or top end of the engine go with what they say because they know more than I do about this stuff. I'm going to spend more time on this forum and find that inforamation out.
Cleaning the EGR and PCV values helped my Trooper in a huge way but still using oil because the rings had baked on crud.I'm going to use Auto-RX to clean the lower end of the engine and based on everything I have found out is the right solution.I look forward to posting the results.
Merry Christmas and I hope this helps someone.
-- Edited by trooper_march02 on Thursday 23rd of December 2010 02:04:29 PM
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2002 Trooper Limited (75k miles so far 2010) / 1992 Trooper LS (200k miles on it when I sold and it is still running strong)
