Offroad-Express

Hello there
Im very interested in buying a 98 or 99 Wizard.
The problem is I've heard that the change from the pushrod 98 model to the DOHC the 99 model never worked.The DOHC was a horror engine.
Is this true ?
I like the look of the 99 but if the engine is no good then I'll buy a 98.

Thanks in advance for your help

Regards

:scratch: Hmmm... what engines are you referring to? The most common petrol most of the Isuzu trucks came with was a 3.2V6 which was the 6VD1 DOHC (I believe there was a SOHC variant), although most Wizards here had the diesel engine.

There is a 3.5 petrol V6 I think but I haven't actually seen one in the flesh and I couldn't tell you if they were a pushrod motor - seems like an old technology to put in a new motor - most of my experience is with pre-96 Isuzu tho so Google might be your friend with this one...

Steve

Sorry I never put diesel.
not petrol

Ok, more info required - what engine models? Diesel engines are not commonly referred to by pushrod or DOHC - they use injectors and a timed pump or a common rail with timed injectors rather than valves...

Steve

SupraLux wrote:Ok, more info required - what engine models? Diesel engines are not commonly referred to by pushrod or DOHC - they use injectors and a timed pump or a common rail with timed injectors rather than valves...

Steve

Air still comes in the valves Steve!!

The 4JG2 3.1 litre was pushrod
The 4JX1 3.0 litre was DOHC.

Thanks for that clarification NJV6. I did actually want to know that.

So my question still stands with a little help from NJV6.

Was the 4JX1 3.0 litre was DOHC engine a lemon ?????

If so then I will chase down a 4JG2 3.1 litre was pushrod model

I do need your assistance if you know.

Regards

I know someone with the 3.0L Wizard and the engine expired a few months ago coming up the Bombays. He said it normally got hot coming up there with 33" tyres etc. While the temp didn't go through the roof (on the gauge), it still ceased.

Another one I know with the earlier 3.1L also got hot, but without the same terminal result.

NJV6 wrote:The 4JG2 3.1 litre was pushrod
The 4JX1 3.0 litre was DOHC.

Now that's bizarre.
Previous workplace had an Isuzu van (4JB1 powered) with a "replace timing belt" light. A strange inclusion on a pushrod motor powered vehicle.

KiwiBacon wrote:

NJV6 wrote:The 4JG2 3.1 litre was pushrod
The 4JX1 3.0 litre was DOHC.

Now that's bizarre.
Previous workplace had an Isuzu van (4JB1 powered) with a "replace timing belt" light. A strange inclusion on a pushrod motor powered vehicle.

They still have a timing belt for the injector pump and the camshaft.
I don't know much about the 3.0 engine, but I was told to avoid it as they apparently have hydraulic problems with regards to the valves.

Jezza wrote:They still have a timing belt for the injector pump and the camshaft.
I don't know much about the 3.0 engine, but I was told to avoid it as they apparently have hydraulic problems with regards to the valves.

Interesting. Most of my time is spent with the bigger 4cyl Isuzu's, I haven't had my hands or spanners on the little ones.

Keep in mind there are two very different 3.0 litre engines. The 4JH series which was sold here in Rodeos and others. It's mechanical injection, maybe with electronic management. Very different to the 4JX.
Dunno what the diff is between the 4JG and the 4JH (besides the displacement).

Air... of course... valves for air... doh!

The 4JG2-T I had (pushrod motor, apparently) expired while on an overnight trip... personally I liked the motor but I'd never trust another one - they have a reputation for popping heads... cracking / overheating... cost me $2500ish to get repaired... And when it was done I was told it was a common occurance in that engine...

Steve

Thanks for thr replies so far, but I still need help with this.

Is there any automotive experts that have experience with these two motors ???

Thanks

What do you want to know? Steve mentioned GOOGLE.... try it, Type in the engine code. I just did and came up with heaps of info....

What do I want to know ??

The answere to my question of course.

I would of expected coming to a 4WD Isuza forum, I may of come to the right place.

not my views or experiance but at least something to read.

Pro for 3.0 4JX1
On paper, a much more powerful and economical engine then the 4JG2-TC.
Probably the very 1st common rail diesel in a 4WD anywhere. Trooper with
this engine are newer so should have wider tread and therefore, more stable.

Con for 3.0 4JX1. From what I read.
1. Probably one of the least reliable diesel engine from Isuzu. Major
injector problem issue that will cost a bomb to repair, assuming you can
find an competent mechanic in the 1st place. Oversea, there has been major
recall for this engine but in Malaysia, you can forget about Isuzu helping
you on this count.
2. EXTREMELY particular about the EXACT type of engine oil to be used.
3. 4JX1 was never officially available in Malaysia so you must be looking
at grey import so you can probably forget about getting injector spares.

The 4JG2 is rumored to be a sized up version of the 4JB1 2.8, one of the
more successful "unbreakable" Isuzu diesel. I had a 4JB1-T and find it to
be extremely economical & reliable. The only problem with 4JB1 is the noise
that you can heard from a mile away but that is partly to do with it
running on timing gear that never need replacing for the life of the
engine. IMO, can beat the crap out of a Toyota or Mitsubishi diesel of the
same age and capacity in reliability and mechanic grape vine rumor seems to
confirm that.

I now have a 4JG2-TC and find it as reliable as the 4JB1-T but definitely
not as fuel efficient, even after taking into consideration the increased
vehicle weight and capacity (3.1 vs 2.. I believe the main reason is
because the former is now inefficient Indirect Injection whereas the later
is very efficient Direct Injection (again, probably one of the very 1st DI
diesel in an 4WD anywhere). I think Isuzu went technologically backward
with the newer 4JG2 mainly because they wanted to reduce the noise.

Based on educated guess because I have never seen a 4JX1 in real life, I
would advise you to stick to the less powerful & efficient 4JG2-TC and not
touch the problematic 4JX1. My 2 sen.

My 4JG2-TC manual transmission gives about 18 sen/km or 8.8 km/L. Not great.


after hours of searching the internet,i finally found the horsepower difference between the 3.0l (4jx1) and the 3.1l (4jg2) engines.

159hp for the 3.0 and 115 for the 3.1!

44hp difference!!no wonder it faster


3.0L engined Troopers want to go the other way, they may be powerful but they have some fundamental design flaws that lead to the engines lunching themselves big time, even afetr the factory modifications that are supposed to fix the problems


........................................
Hard to say i can't find much about what the problems are meant to be but everyone seams to think they have problems

imlost wrote:What do I want to know ??

The answere to my question of course.

I would of expected coming to a 4WD Isuza forum, I may of come to the right place.

By the lack of responses it may have been that no-one knew and it required a search...... As rangimotors confirms there is loads of info in the net.

Well it took 4 months but I finally decided on a 95 Mu with a 4LG2.
Now your going to have to put up with some more stupid questions as its my 1st 4WD.
Regards

The 2.8 4JB1T is the best 4wd isuzu motor by a country mile and one of the best small diesels to come out of Japan. Did 120,000ks in one (sold it at 220k) and ran like a charm. Have several mates with them running well into the 3-400,000k range and all going good. There is one light isuzu truck I know of in chch with a 4JB1T which has done over 1,000,000ks and still going well - another coming up 600,000ks. Two things with the 4JB1T - they must not be overheated as this stuffs the chrome bore liner which is responsible for the long motor life. Also they must be oil changed every 5k - though this is standard for most diesels. Economy with the 2.8 is very good - 30-32mpg. Standard horsepower 110-115, but very easy to tune up to 140hp+. Mine dynoed at 155hp - handled this level of tune with ease for 100,000ks. 4JB1T still fitted to trucks new in different parts of the world after 20 years in production.

The 4JG2 is not quite as good a motor - occasionally prone to headcracking - have heard removal of the egr equipment may help this. Less economical - 24-27mpg, but quite a few trucks still run up 3-400,000ks with this motor. It does have a turbo issue - the turbos have to be replaced at round 125ks at about $1000 apiece. 120-125hp - isuzu specs site.

4JX1 had major O-ring issues with injectors (a system derived from Cummings) and you should only buy a truck if this job has been done. Motor can run very well - good power - but is not well regarded by diesel mechanics. Know of one diesel shop that won't touch them now. Has sensors for everything and faults can be quite problematic to find.

If choosing between 4JG2 and 4JX1, I'd go for the former if the turbo has been done - and make sure you keep the radiator clean..

imlost wrote:Well it took 4 months but I finally decided on a 95 Mu with a 4LG2.
Now your going to have to put up with some more stupid questions as its my 1st 4WD.
Regards

Good on ya . They are a fun little truck and won't let you down.