Would someone PLEASE explain, once and for all...

[madizell]

Don't brand bash, I agreed with everything you said until the last sentence.:

Not bashing the brand. It was not I who suggested that a modern engine should consume a high rate of oil. And, the last time I looked, Isuzu was withdrawing most of its model line from the US market, and was left at this point with a made over Chevy SUV (Ascender) and 3 variants of essentially the same small truck, but then I don't follow Isuzu (nor really any others either). Still, one SUV and one or two trucks doesn't make up a full product line in today's market place. Observations based in fact do not constitute bashing, merely reporting.

The service problems with Isuzu products in the past few years are a matter of public record, and again, discussion of such problems do not constitute bashing. My use of the word "junk" would be about as close as I came, and it was a predicate use of the word, given the context.

 

[madizell]

if the "smoke" dissipated quickly (which would be steam), or hung around a little longer (indicating smoke).

Not necessarily a definitive standard. Steam would necessarily have been caused by water of some sort. If coolant, then there would be a definite odor because antifreeze has a distinctive smell when burned. But if it was coolant, then you would have a constant loss of coolant as you drive, not to mention other possible symptoms. Bottom line is you can't consume coolant indefinitely, the radiator will run dry. If you don't have this problem, it was probably not coolant on start up. That would be good news.

I don't know how to verify worn valve guides by other than visual inspection. If you are getting only 1,000 miles out of a quart of oil on a regular basis, I think it will soon be time to do something about it.

Long block refers to a remanufactured or new engine assembly that includes heads. A short block does not include heads. In an engine replacement using a long block, you will swap all accessories, and from the old engine provide the intake and exhaust systems, and depending on the source, perhaps timing cover, water pump and such, and quite possibly the oil pan.

 

[madizell]

Where would you recommend obtaining a new long block that will have all the necessary adjustments and upgrades present?

Here's one:

http://www.powerpro2000.com/lb_isuzu.htm

I don't have personal experience with any engine reman businesses, so I don't "recommend" this one, either, but the thing to do, if you go this route, is contact prospective suppliers and talk to them about their product and their warranty. Power Pro offers what looks to me to be an excellent warranty.

 

[madizell]

Just for ****s and giggles, let's assume that you're right.

If I can find a reputable mechanic (no way in hell I'm going to a dealership on this unless I am strongly urged to do so by those in the know), what do I ask them to look for, examine, etc.? I don't want them disassembling the engine if it's not needed.

I just wish I knew more about this stuff. Pisses me off to be so clueless about it.

Assuming you have 95,000 miles on the clock, consume oil at something more than an acceptable rate, seem to have some oil leak-down if the motor sits for a while, and you are worried about the longevity of the current engine, I would not even consider trying to have a mechanic work on only one part of the engine, such as the heads, because of the cost, and because most truly reputable mechanics will shy away from doing it. They know that as soon as you sink dough into a head rebuild, the next thing to happen will be rings and pistons, rod and main bearings, or whatever, and they will be blamed for doing "bad" work when the next problem shows up. So, most will suggest an engine swap before patching up worn parts one at a time.

Doing a head rebuild would be most feasible if you were able to do the work yourself (pulling and replacing heads, not the rebuilding part). That way you only pay for the machine work, parts, and gasket set, and save hundreds in labor. If you are not able to do the work, you probably won't want to try swapping in a reman engine either. So, ask that mechanic what he charges to do the swap, and ask him if he has experience with a supplier of long blocks. Paying him to swap out the block will be far cheaper than trying to rebuild your current engine.

 

[Zaphod]

Thanks again. Maybe I'll do just that.

Well, I don't think I'll be able to do any of this myself, and certainly not within a reasonable timeframe, so it will be best to let the pros do it. What I have to decide now is whether to just try and keep this badboy running as-is, or take advantage of the fact that not only do I need to fix the problems noted, but I also need to do the timing belt, water pump, tranny cooler install, etc., and just have them do it all in one fell swoop.

For the time being, I'm going to flush the hell out of it (far cheaper than an engine swap). If it works, then fine, and I'll do the timing belt and such. If not, then more drastic measures will be needed.

Regardless, I have to have them do a GOOD tranny flush and inspection, along with installing an additional Tranny cooler. It's been trouble-free as far as I can tell, and I want to keep it that way.

Now, if I could just find a place that could install a moonroof. :smilies27

 

[Incusus]

While I will agree that it is bunk to say that it is acceptable for a company to claim 1 qt over 1000 miles of consumed oil is with in "spec" Isuzu is not by any means "fading from the market" they have removed themselves from the light truck and SUV market but they are one of the largest manufactures of large trucks and more importantly diesel powerplants (duramax). Don't brand bash, I agreed with everything you said until the last sentence.

ROFSheriffHL:

As much as I love Isuzu, I have to disagree. I live close to and have intimate knoledage of the inside of a local Duramax engine plant. It's staffed with General Motors engineers, and transplant workers from a GM truck and bus facility.

I'm not "brand bashing", but Duramax diesel engines are about as Isuzu as a Chevy dualie.

 

[endo]

I humbly stand corrected then

 

[datrupr]

I bought my Trooper (98) with roughly 60K on it. It now has over 150K. I have had virtually no trouble with it. Starter failed at around 95K. Now mind you that I am telling you all this while I sit waiting in a shop for them to replace my o2 sensors so I can pass emissions. But other than that it has never failed me. I have learned to live with the oil consumption, and budget $ for additional oil.

Also, it is wise to replace/rebuild the tranny if you plan on doing the same with the engine. Old trannies mated to a new engine can spell disaster. Just my $.02

 

[madizell]

forgive me if this has already been discussed... the problem with the isuzu engines is reportedly with oil not leaking back down into the crankcase, and subsequently getting pushed up past the rings and into the combustion chamber right?

I don't think so. If oil can't run back "down" into the engine, then it is trapped in the heads. This has nothing to do with rings. We all need to map out in our heads where oil travels in an engine in order to get the sense of what is happening.

Moreover, oil can get to the combustion chamber through two basic paths: 1) past the rings from the lower engine block (i.e. oil pan) by traveling up the piston skirt/cylinder interface, passing the oil and compression rings and up into the combustion chamber; or 2) down from the heads past the valve guides into the intake or exhaust tract and thus out the back door.

No head design I have seen so limits migration of oil from head to oil pan such that increased oil consumption results. They all have passages that allow oil to drain back to the sump so quickly that it does not even count. If that were really the problem the oil pump would run out of oil because all the oil would be pumped to the heads and none would return to the sump fast enough to recirculate. Still, all heads pool some oil in casting pockets, most hold some oil near on on valve guide tops, and all will cause some oil leakage into the combustion chamber is the tolerances between guide and valve stem are too great.

In the case of the Isuzu, I don't know if the oil consumption is past the rings or past the valve guides. Also don't know if the problem is consistent.

 

[endo]

I don't think so. If oil can't run back "down" into the engine, then it is trapped in the heads. This has nothing to do with rings. We all need to map out in our heads where oil travels in an engine in order to get the sense of what is happening.

Moreover, oil can get to the combustion chamber through two basic paths: 1) past the rings from the lower engine block (i.e. oil pan) by traveling up the piston skirt/cylinder interface, passing the oil and compression rings and up into the combustion chamber; or 2) down from the heads past the valve guides into the intake or exhaust tract and thus out the back door.

No head design I have seen so limits migration of oil from head to oil pan such that increased oil consumption results. They all have passages that allow oil to drain back to the sump so quickly that it does not even count. If that were really the problem the oil pump would run out of oil because all the oil would be pumped to the heads and none would return to the sump fast enough to recirculate. Still, all heads pool some oil in casting pockets, most hold some oil near on on valve guide tops, and all will cause some oil leakage into the combustion chamber is the tolerances between guide and valve stem are too great.

In the case of the Isuzu, I don't know if the oil consumption is past the rings or past the valve guides. Also don't know if the problem is consistent.

There are TSB's about the rings and excess oil consumption dealing with a ring redesign for oil ports.

1999 Isuzu Truck Trooper V6-3.5L
Vehicle Level Technical Service Bulletins All Technical Service Bulletins Engine - Oil Consumption Usage Testing/Reporting


Engine - Oil Consumption Usage Testing/Reporting


TSB SB04-01-S004

Engine Oil Usage Testing and Reporting
(This Bulletin Supersedes IB00-01-S002)

ISSUE DATE: OCTOBER 2004

Affected Vehicles
All Isuzu Models.

Service Information

This bulletin has been revised to include new detailed procedures when completing the new updated Engine Oil Usage Test/Report. Please disregard information found in Isuzu bulletin IB00-01-S002.

Before performing any warranty repairs, based on a customer's complaint of excessive engine oil consumption, the Engine Oil Usage Test/Report shown must be completed in full.

The updated Engine Oil Usage Test/Report is divided into two parts, PROCEDURE # 1 and PROCEDURE # 2.

Procedure # 1, the inspection and testing portion of the Engine Oil Usage Test/Report, are eligible for warranty submission. Procedure # 1 warranty claim may only be submitted ONE time per vehicle. Review Procedure # 1 Results and perform the appropriate action. Complete all steps in Procedure # 1 before continuing on to Procedure # 2 (if required).

Procedure # 2, the validation portion, is NOT reimbursable under warranty. Complete all steps in Procedure # 2. Review Procedure # 2 Results and perform the appropriate action.

The Technician, Service Manager and Customer are to acknowledge the findings by signing and dating the bottom of the Engine Oil Usage Test/Report. Attach a copy of the completed report to the back of the Repair Order (R/O) hard copy and provide a copy to the customer.

NOTE: 1. Normal authorization procedures must be followed for such repairs.

2. Information released on paper and electronic format prior to bulletin release cannot be updated. For the most current and up to date information refer to IsuzuONE.com.


ENGINE OIL USAGE TEST/REPORT FORM

This Service Bulletin is intended for use by professional, qualified technicians. Attempting repairs or service without the appropriate training, tools, and equipment could cause injury to you or others and damage to your vehicle that may cause it not to operate properly.

the issue is summarized as "cause is inadequate drain-back holes in the oil control rings. The consumption seems to be mostly an annoyance & doesnt effect performance or reliabilty. Old design has something like 4 holes, new design has 10+ holes. On the old design, oil gets trapped above the ring(s) and burns off in the cylinder. Gets worse as the vehicle ages & the rings get dirty with age"

 

[Zaphod]

Also, it is wise to replace/rebuild the tranny if you plan on doing the same with the engine. Old trannies mated to a new engine can spell disaster. Just my $.02

I'll keep that in mind...