Rodeo oil

[slickfisher]

My wife just had to have an 02 Isuzu Rodeo. I knew of #1 rod bearing failures they were having. However the new DOHC engine was much better than the SOHC motor with the auxilary rocker shafts.
I've been using Mobil 1 10-30 (10-30) specified by Isuzu. I believe M1 10-30 to be a good oil but I know the 5w40 has some shear issues. I'm wondering if M1 is the best oil for my Isuzu. I would run GC but that's reserved for the VW 1.8T. I'm thinking of Valvoline's synthetic.
The failures of all the engine's I've inspected (I'm a mechanical failure inspector by trade) show spalling and/or slight scoring to #1 rod bearing only with all other bearings showing debris damages only.
Anywho, anyone have any suggestions on a good lube for the Rodeo. I usually run a 5k mi. OCI but since the price of M1 is so high I though to take it to the OEM 7.5k mi. OCI.
Results have been pretty good with the M1. This engine is know to be an oil user and I usually end up using about a qt every 5k mi.

Anybody got suggestions?

 

[JTK]

I own a 2002 as well. Per the manual, anything from 20w-50 to 5w-30 is fine dependant on your ambient temp. Thanks to BITOG

, Over the years, i've experimented with 15w-40, down to 5w-20

, just to see what 'effect' the various viscosity ranges have on valvetrain noise, engine performance, oil consumption and fuel economy. No UOA's to offer. I'm about ready to dump my second run of 5w-20. My 3.2L runs as smooth as silk on it, no noticeable consumption and a steady 20 mpg hywy, but I'm having second thoughts about continuing use of 5w-20 with the direct-attack / direct acting valvetrain these engines have, so I'll probably stick with a 5w-30. I currently have a case of kendall 5w-30 synth blend in my collection and a new carquest premium filter to go in. I don't see how you could go wrong with a M1 30 or 40wt variation!
G/luck
Joel

 

[tmf2]

> I believe M1 10-30 to be a good oil but I know the 5w40 has some shear issues.

I was under the impression from various posts here
that the Mobil Truck & Suv 5-40 weight was pretty
much bulletproof and very resistant to shearing.

Dennis

 

[slickfisher]

quote:

---

Originally posted by tmf2:
> I believe M1 10-30 to be a good oil but I know the 5w40 has some shear issues.

I was under the impression from various posts here
that the Mobil Truck & Suv 5-40 weight was pretty
much bulletproof and very resistant to shearing.

Dennis

---

Sorry mistype. I used 0w40 Mobil 1 in my VW Jetta 1.8T ( met VW502 spec unlike the 5-40

). That's the oil I was refering to when I said shearing.

To the prior poster. The valvetrain design is classic cam over bucket design. Been around for years. It's very simple and straight forward and pratically bulletproof. Especially when one considers the lifters are solid! My favorite design by far. Millions of VW/Audi inline fours/fives have been on the road for 3 decades with that design and no wear/failure issues, even using mineral based oil.

 

[JTK]

quote:

---

Originally posted by slickfisher:
... The valvetrain design is classic cam over bucket design. Been around for years. It's very simple and straight forward and pratically bulletproof...

---

Yep, very true, but do any of today's 5w-20 spec'd engines have a cam on bucket valvetrain?

Joel

 

[Ramblin Fever]

I have the older 3.2L V6 SOHC and I'm running Rotella 5w-40 synthetic.

Use to run Havoline 10w-30 for 140K miles.

You say the SOHC was known for rod bearing failures? I have heard of some, but never knew real reasons as to why they were failing, aside from low oil in the crankcase.

What's your observations on that particular engine, the 3.2L SOHC, as to cause of the failures you've seen?

I've been one of the lucky one's, I gather, only use 1/8-1/4 qt in 3k miles.

 

[JTK]

Ramblin, I was waiting for you to hop in!

In the years I've been hanging around isuzu boards i've never seen reports of #1 rod bearing failure on the 1993-1997 isuzu 3.2L The only reason they 'fail' on the 1998+ 3.2/3.5L is because owners let their trucks run low on oil. That bearing is the first one to starve.
G/luck
Joel

 

[Ramblin Fever]

You're gettin to know me too well

Guess I'm making up for lost time - never knew Isuzu boards existed til just the last good year or so. I think I'd given up actually, as when I first bought the 2nd Rodeo, couldn't EVER find other informative owners online, nor could you find any aftermarket accessories.

And with the first Rodeo, 1991, all I ever got was such responses as "you drive in the Rodeo?"

Or "what's THAT you drive - a Roadayo?"

Thanks for the insite - wasn't quite sure, actually if he was refering to the SOHC or DOHC, thanks for clearing that up.

 

[slickfisher]

quote:

---

Originally posted by Ramblin Fever:
You're gettin to know me too well

Guess I'm making up for lost time - never knew Isuzu boards existed til just the last good year or so. I think I'd given up actually, as when I first bought the 2nd Rodeo, couldn't EVER find other informative owners online, nor could you find any aftermarket accessories.

And with the first Rodeo, 1991, all I ever got was such responses as "you drive in the Rodeo?"

Or "what's THAT you drive - a Roadayo?"

Thanks for the insite - wasn't quite sure, actually if he was refering to the SOHC or DOHC, thanks for clearing that up.

---

Yes, I am refering to the DOHC engines 98 and on. The earlier SOHC engines had the auxilary shaft problem and few if any lower bearing problems. They were actually more of an anoyance than an issue- at least in the beginning stages. The intake rocker shaft (pre 98s) had oil gallies too small and would not lube the auxilary rocker arms and other arms sufficently. The result was a noisey valvetrain that eventually would fail many times. I inspected dozens of these claims. The engine I was talking about is the current, well, up to 05, DOHC engine where the #1 rod bearing would fail. It isn't a LOL failure as all other bearings appear without LOL distress. And #1 rod bearing is the closest to the pump- usually the last to go on a run low scenario. This is a know issue to Isuzu. Many engines have been replaced for this failure. I asked a field engineer about it while doing an inspection one day and he didn't give me a straight answer- naming numerous causes: ie- they don't know. I believe it is either a quality/tolerance issue or a design flaw related to changing to the new head design. The theories are endless. But I don't believe it is directly lubricant related, but that doesn't mean a really good oil wouldn't hurt. Remember also that that is an all aluminum engine with only 4 main bearings. It really is quite a nice piece of work, if they'd get the kinks out. I just drove mine on a 200+ mile run today, good power, relatively poor fuel economy, and so far very reliable. And yes one does wonder of the pressure's relative to the cam over bucket design, but other mfg's use it with thin oils and survive. I dunno

.

 

[mdocod]

quote:

---

The earlier SOHC engines had the auxilary shaft problem and few if any lower bearing problems. They were actually more of an anoyance than an issue- at least in the beginning stages. The intake rocker shaft (pre 98s) had oil gallies too small and would not lube the auxilary rocker arms and other arms sufficently. The result was a noisey valvetrain that eventually would fail many times. I inspected dozens of these claims.

---

i've been looking for some technical explanation of the annoying tick for a long time... and now i am starting to get a better grasp on the problem.. I have a 1995 SOHC 3.2L 24V, almost 180,000 miles now... it's been tickin for the last 30k... "engine restore" helped it quiet down for awhile.. but probably just made things worse in the long run... GC was by far, the quietest run it's had, with the smoothest startups in the last 20k or so.

I had a question for ya slick-

If the problem is do to a lack of flow- but these engines don't suffer in the begining- then is it true, that the flow is reduced over the years by contamination- thus the reason the TSB for this issue recomends lightweight synthetic to help flow better and clean out the galleys? Reason I ask is- I'm hoping, praying, that my just recently started ARX treatment on this will help fix this issue.. ya think there's a prayer for the arx to fix it? I had to switch back to dino, using 5w30 supertech to maximize the effects of the ARX... and it's louder, as soon as i switched away from GC to the dino, the ticking is louder, i'm really worried it might not survive through the cleaning cycle on the dino.

It's ashame the isuzu engines have been so flakey over the years, between consumption and ticking. The rest of the thing is overbuilt so well.

 

[pinoy99]

If you have to add a quart towards the end of OCI cycle 5k, then might as well extend the M1 10w30 to 7.5k miles.

One oil you might consider is Shell's Rotella 5w40.

 

[pinoy99]

I've used a lot of diff weight/brand oil on my Trooper but have yet to try the Rotella. I have some 10w40, 0w40, 5w40 of diff brands to use up before I can.

 

[JTK]

quote:

---

Originally posted by slickfisher:
..The engine I was talking about is the current, well, up to 05, DOHC engine where the #1 rod bearing would fail. It isn't a LOL failure as all other bearings appear without LOL distress. And #1 rod bearing is the closest to the pump- usually the last to go on a run low scenario..

---

I have to think this in some way is low oil level related. I've been following this issue for about 4 years and have seen about a dozen reports of rod bearing failure (always #1) on the 1998+ isuzu 3.2/3.5L. It always followed the same scenario:

1) The truck was a known oil 'consumer' and used in excess of 1qt/1000 miles.
2) The owner rarely if ever popped the hood, checked fluid levels, etc.. Non BITOG'er type

.
3) The owner never changed their own oil. Used quicky lube places.
4) The engine was low on oil when the 'knock' began and rod bearing spun/failed.

The last year of production for the rodeo and 3.2/3.5 was 2004. The trooper's last year was 2002. I've got three of the darn things in my family

.

G/luck
Joel

 

[JTK]

 

[Ramblin Fever]

Pinoy99 - are you running Shell as well?

Just started using the Rotella 1300 miles ago.

I was leary of running the TSB recommended oil of 0w-30 Mobil 1 on an 8yr old truck with 145k mile old seals/gaskets.

So I thought a heavier detergent oil would help.

I, for what-ever reason, and I'm NOT complaining - don't have the tick anymore.

I can only link that to the Rotella, but I honestly don't know.

It's not like mine had been plagued with it for long, though, so someone elses results with different oils may not be the same.

 

[slickfisher]

quote:

---

Originally posted by mdocod:

quote:

---

The earlier SOHC engines had the auxilary shaft problem and few if any lower bearing problems. They were actually more of an anoyance than an issue- at least in the beginning stages. The intake rocker shaft (pre 98s) had oil gallies too small and would not lube the auxilary rocker arms and other arms sufficently. The result was a noisey valvetrain that eventually would fail many times. I inspected dozens of these claims.

---

i've been looking for some technical explanation of the annoying tick for a long time... and now i am starting to get a better grasp on the problem.. I have a 1995 SOHC 3.2L 24V, almost 180,000 miles now... it's been tickin for the last 30k... "engine restore" helped it quiet down for awhile.. but probably just made things worse in the long run... GC was by far, the quietest run it's had, with the smoothest startups in the last 20k or so.

I had a question for ya slick-

If the problem is do to a lack of flow- but these engines don't suffer in the begining- then is it true, that the flow is reduced over the years by contamination- thus the reason the TSB for this issue recomends lightweight synthetic to help flow better and clean out the galleys? Reason I ask is- I'm hoping, praying, that my just recently started ARX treatment on this will help fix this issue.. ya think there's a prayer for the arx to fix it? I had to switch back to dino, using 5w30 supertech to maximize the effects of the ARX... and it's louder, as soon as i switched away from GC to the dino, the ticking is louder, i'm really worried it might not survive through the cleaning cycle on the dino.

It's ashame the isuzu engines have been so flakey over the years, between consumption and ticking. The rest of the thing is overbuilt so well.

---

If it wasn't so late I would dig up some amazing photos of the intake rocker shaft and the amount of wear running engines endure on the shaft. The gallies are litterally plugged and the amount of scored indentation on the shaft is like 1/16" or more! The average repairs are in the $3-4k range.

To the last guy whom posted. I'm pretty sure it's not a lack of lube issue. Isuzu is replacing a bunch of engines under warranty for this failure (they're very expensive- complete!) and believe me if it were a lack of lube they would wiggle out of it. I've seen engine's so clean that you could eat of 'em. That usually doesn't happen when you change oil or keep it topped up. These engines also have a temp problem on the pistons. The EGR tube dumps at the front of the intake. The dealers really push keeping that tube clean, cause if not the piston temps rise and coke up scraper rings and up goes the oil consumption.
One would think if there was a run low the cam saddles would show it at the back of the heads, but they always look good.
It's just hard to accept a run low explanation when all the other bearings in the engine look cherry except for debris from #1. It is also imposible for that scenario to hold up in court.

 

[mdocod]

quote:

---

To the last guy whom posted. I'm pretty sure it's not a lack of lube issue

---

so- the ticking, and the wear, is in no way related to plugged up galleys?

 

[JTK]

Slick- No doubt the 1998+ 3.2L EGR system is a PITA, but easy to troubleshoot and clean. The EGR feed tube that dumps into the common chamber takes about 5min to flush clean with a can of intake cleaner. Dealers will charge in excess of $100-200 for that job. We've also got some 'experiments' going on, on various isuzu boards where owners area doing overnight cylinder soaks to clean the piston ring packs to *hopefully* stop the oil usage. It's a shame this series of engines needs this type of attention. They are sweet running engines with lots of power. There are many owners now with way over 100K miles and no problems. They just are not the *maintenance free* type of truck!
G/luck
Joel

 

[Ramblin Fever]

quote:

---

Originally posted by mdocod:

quote:

---

To the last guy whom posted. I'm pretty sure it's not a lack of lube issue

---

so- the ticking, and the wear, is in no way related to plugged up galleys?

---

Think Slickfisher is referring more towards the post-98 3.2L's rather then the pre-98's.

I may be wrong, though.

 

[mdocod]

I was gona do the EGR thing on my 95 here soon... maybe on monday i'll have some time...

Is it really thay easy- i was looking at the EGR valve and the tube running back behind the motor.... i guess it looks harder to get off that it is, idunno....