Thread: 1997 Isuzu Bighorn

Hey team,

I have got rid of the Freelander and looking at getting a 97 Bighorn. 3.1ltr, auto in standard Green. 240K

Quick drive in it last night everything seemed fine, bit of a clatter and did run a bit rough on start up but that went away. Brakes seemed average but could be standard Bighorn, but I am not sure. Everything else seems to work fine. Bit bigger than the Freelander

Turbo has just been replaced, timing belt light is on but will try and find out when the belt was replaced as it may just be the light has not been reset. It looks like it has lived by the sea and has a bit of surface rust on the chassis etc so will hit that with rust killer and paint as soon as possible.

Anything I should be looking for before purchasing? Any improvements that I should look at doing when I get it. Pretty new to this type of vehicle so any replies are appreciated.

Cheers
Daniel

I've got one the same year, 280k 3.1 diesel, fairly good SUV, but heavy and slow.
Check front CV joints, will click when turning, at full lock if worn. in $X$ (4x4) both mine have failed,
I had a bolt come out on the torque converter, and get jammed between the flywheel and housing, locked up engine, so had engine, out to repair, luckily this happen in the driveway, I was attempt to figger out the noise at the time. rebuilt Engine while I had it out.
Check glow pugs are all working, or it will be hard starting when cold, $20 each.
I bypassed the emission's egr in mine, was heavily plugged with carbon and soot,
4" exhaust will improve power, as engine can breather better,
turbo waste gate line can be plugged off, for better response,
I wouldn't recommend spending a bunch, on trying to increase performance, its an old vehicle, with a heavy pig of engine, and heavy body, ride ok, but no racehorse.
find out about the timing belt.

They are known for being 'smoky' on start up, particularly in cold weather. Just unburnt fuel from engine management mucking about. Check the vacuum hoses for the brakes as they do perish.

Took it for a good run, drives OK, most things seem to work. Current tyres are shit off road, 4wd did work, was really wet where I went and it struggled in places. Shot one duck on my test drive (and missed a few more). When engaging and disengaging 4wd the light doesn't work.. will try and fix it, but do I need back up a bit to disengage 4wd or anything like that?

Going for a WOF on Monday so as long as it passes then I will buy it.

Originally Posted by GMH72

Took it for a good run, drives OK, most things seem to work. Current tyres are shit off road, 4wd did work, was really wet where I went and it struggled in places. Shot one duck on my test drive (and missed a few more). When engaging and disengaging 4wd the light doesn't work.. will try and fix it, but do I need back up a bit to disengage 4wd or anything like that?

Going for a WOF on Monday so as long as it passes then I will buy it.
Attachment 71115

Jack the tail end up and check if it is open or LSD rear end. Spin one wheel. If the other side spins the same way LSD, if the wheel spins the opposite direction open diff. Can be a lottery which one you get. They are pretty good for a factory vehicle with the LSD.

If it has G80 in the options codes on firewall plate its LSD. Unless its been swapped out.

The alternator is a nightmare to replace. Try something like 8 hours...
Make sure the battery is good, ideally fit a secondary battery system if yours doesn't already have it.

Originally Posted by peril 787b

The alternator is a nightmare to replace. Try something like 8 hours...
Make sure the battery is good, ideally fit a secondary battery system if yours doesn't already have it.

I replaced mine in an hour, and I'm no grease monkey.

3.1 4JG2 Isuzu motor quite a good diesel. Based on the earlier 4Jb1 2.8 which was a beauty. The 3.1 will occasionally crack heads but nothing like as bad as the 2.4T or 1kz series toyotas. Indirect injection system feels like they're a little sluggish to get moving but once up and running they pull quite well. 120-135hp depending on model. Very good box and drivetrain, and easy to modify for club use.

Things to look for with 4JG2 (and most any diesel):
* turbo noise on wind down - $1000 if turbo bearings shot on 4JG2.
* Check steering box for leaks. WOF issue and can be $400 to fix
* Check lower crank pulley for movement (serious) and for oil leaks (easier)
* Check if timing belt done
* Check radiator - well maintained coolant or dirty. No oil or sealant material in it. No temp issues on road test.
* Check excessive fuming - lift off oil filler cap
* Check for excessive engine noise
* Check oil leakages around block, and esp at rear main seal join between motor and gearbox
* Check front CVs and CV boots. If skinny CV shafts (some are very skinny but most 25-30mm diameter) then no good for offroading
* Check 4wd in both high and lo ratios when driving
* Check if LSD (G80 on options plate on firewall) or by wheel spinning test
* Check even tyre wear and alignment on road. Half worn muds no good for club offroading - that's when we sell them.
* Check auto smooth changes and at right revs - changes smoother after running 5-7 minutes.
* Check for smoking - puff of blue on start up ok, and bit of grey or black ok when running. Not white.
* Check rear pinion and axle/hub seals not leaking
* Check for vibrations/noises when driving - can be universals, driveshaft hanger bearing, wheel bearings, rear diff etc
* Check it has adequate power
* Check all window operations - they all cost money to do.
* Check every electrical item
* Rust check every panel and underneath.

Run through this checklist and you'll troubleshoot most diesels. Before about 95 (approx) 4JG2s are usually mechanical diesel pumps and easy to tweak timing and diesel flow for 15 more hp. After round 95 usually electronic pumps and harder to tweak. 2.5" bigbore from turbo allows greater airflow, gives them extra hp and brings turbo in boost sooner. I wouldn't expect a 20 year old diesel 4wd to be perfect - just a matter of noting work that needs to be done, checking its cost, and coming to a fair purchase price.

Thanks for all the replies guys... it passed a WOF, small oil leak noted and no mention of anything else.
Its not the LSD version but I don't think that is an issue for what I will need it for.
Timing belt would be the only issue that I need to check and replace.
All electrics seem to work fine. There is a switch on the left, engine with a glow plug symbol... can anyone tell me what it does?

I think that is an 'idle up' switch. Increases the revs a bit, like a replacement for the older style knob where you could set your own revs when cold.

Great, thanks for the replies

Originally Posted by gadgetman

I think that is an 'idle up' switch. Increases the revs a bit, like a replacement for the older style knob where you could set your own revs when cold.

Ahhh cheers gm, you have reminded me the knob off the end of my choke lever keeps coming off and I need to glue it back on!!

Hey guys, well the electrics may not work perfectly, on start up it the battery reads under 12v and the heater doesn't go... then after a little bit of a warm up she starts reading up near 14v and everything is OK again. What could be causing this? Anything to worry about? The green 4wd light also goes off when started and doesn't come back on no matter what you do, and sometimes the light around the gear selection (auto) goes off too... so wondering if its a loose earth. I really don't know, be nice to get things working properly, but not a major. Apart from those little things it runs pretty good. Cheers

we had a bighorn, but the mu was far better off road. shame the new mu-x comes in auto only in nz