Last post on Dec 20, 2011 at 7:53 AM
You are in the Isuzu Trooper
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Isuzu Ascender, Isuzu Trooper, SUV
Your Community Leader is paisan.
#3061 of 3299 Re: 1999 trooper please help [pacheaco]
Jul 17, 2006 (10:23 am)
Hi, sorry so long to respond, I thought someone might have a suggestion. Here is what Isuzu says about noises in rear end:
1999 Isuzu Truck Trooper V6-3.5L
Vehicle Level Transmission and Drivetrain Differential Assembly Testing and Inspection Rear
Many noises that seem to come from the rear axle actually originate from other sources such as tires, road surface, wheel bearings, engine, transmission, muffler, or body drumming. Investigate to find the source of the noise before disassembling the rear axle. Rear axles, like any other mechanical device, are not absolutely quiet but should be considered quiet unless some abnormal noise is present.
To make a systematic check for axle noise, observe the following:
Select a level asphalt road to reduce tire noise and body drumming.
Check rear axle lubricant level to assure correct level, and then drive the vehicle far enough to thoroughly warm up the rear axle lubricant.
Note the speed at which noise occurs. Stop the vehicle and put the transmission in neutral. Run the engine speed slowly up and down to determine if the noise is caused by exhaust, muffler noise, or other engine conditions.
Tire noise changes with different road surfaces; axle noises do not. Temporarily inflate all tires to 344 kPa (50 psi) (for test purposes only). This will change noise caused by tires but will not affect noise caused by the rear axle. Rear axle noise usually stops when coasting at speeds under 48 km/h (30 mph); however, tire noise continues with a lower tone. Rear axle noise usually changes when comparing pull and coast, but tire noise stays about the same. Distinguish between tire noise and rear axle noise by noting if the noise changes with various speeds or sudden acceleration and deceleration. Exhaust and axle noise vary under these conditions, while tire noise remains constant and is more pronounced at speeds of 32 to 48 km/h (20 to 30 mph). Further check for tire noise by driving the vehicle over smooth pavements or dirt roads (not gravel) with the tires at normal pressure. If the noise is caused by tires, it will change noticeably with changes in road surface.
Loose or rough front wheel bearings will cause noise which may be confused with rear axle noise; however, front wheel bearing noise does not change when comparing drive and coast. Light application of the brake while holding vehicle speed steady will often cause wheel bearing noise to diminish. Front wheel bearings may be checked for noise by jacking up the wheels and spinning them or by shaking the wheels to determine if bearings are loose.
Rear suspension rubber bushings and spring insulators dampen out rear axle noise when correctly installed. Check to see that there is no link or rod loosened or metal-to-metal contact.
Make sure that there is no metal-to-metal contact between the floor and the frame. After the noise has been determined to be in the axle, the type of axle noise should be determined, in order to make any necessary repairs.
Gear noise (whine) is audible from 32 to 89 km/h (20 to 55 mph) under four driving conditions.
Driving under acceleration or heavy pull.
Driving under load or under constant speed.
When using enough throttle to keep the vehicle from driving the engine while the vehicle slows down gradually (engine still pulls slightly).
When coasting with the vehicle in gear and the throttle closed. The gear noise is usually more noticeable between 48 and 64 km/h (30 and 40 mph) and 80 and 89 km/h (50 and 55 mph).
Bad bearings generally produce a rough growl or grating sound, rather than the whine typical of gear noise. Bearing noise frequently "wow-wows" at bearing rpm, indicating a bad pinion or rear axle side bearing. This noise can be confused with rear wheel bearing noise.
REAR WHEEL BEARING NOISE
Rear wheel bearing noise continues to be heard while coasting at low speed with transmission in neutral. Noise may diminish by gentle braking. Jack up the rear wheels, spin them by hand and listen for noise at the hubs. Replace any faulty wheel bearings.
KNOCK AT LOW SPEEDS
Low speed knock can be caused by worn universal joints or a side gear hub counter bore in the cage that is worn oversize. Inspect and replace universal joints or cage and side gears as required.
Excessive clunk on acceleration and deceleration can be caused by a worn rear axle pinion shaft, a worn cage, excessive clearance between the axle and the side gear splines, excessive clearance between the side gear hub and the counterbore in the cage, worn pinion and side gear teeth, worn thrust washers, or excessive drive pinion and ring gear backlash. Remove worn parts and replace as required. Select close-fitting parts when possible. Adjust pinion and ring gear backlash.
Maybe this will help you!
#3063 of 3299 Re: What to Look For [dfenlon]
Aug 05, 2006 (7:36 am)
Hey! I just bought a '96 w/107k on it. It was at a dealer 250 mi away so I didn't have the advantage of having my regular mechanic give me the up or down sign on it. I ended up driving it home that day. I have the loose steering too, a few degrees to either side. Everything works incl A/C, I've dropped it off at the mechanics so they can give me their list of things needing repair... I hope it's a short list! Otherwise, so far so good and I like it, but like you I'm waiting for the tranny to take a dive tomorrow...
#3064 of 3299 Re: Failing to return to idel speed while driving [bigdogg]
Aug 26, 2006 (5:33 am)
I know the air control valve is bad on my 1993 Isuzu pickup and I have the replacement part, but I have been unable to locate where it goes. Do you know exactly where it goes?
#3065 of 3299 Idle Air Control Valve
Aug 26, 2006 (5:34 am)
Can someone tell me exactly where this located on a 1993 Isuzu 4X4 pickup?
#3066 of 3299 Re: Idle Air Control Valve [waterman2]
Aug 26, 2006 (8:16 am)
You don't mention the engine you have, but I think it is the 2.3 If not, I am not sure if this will help you. It is located on the throttle body; If you look you should see the throttle position switch mounted opposite the bellcrank that opens the intake butterfly and has a wiring harness. The next electrical device behind the bellcrank should be the IAC valve, which also has a wiring harness. Some had flange nuts holding them on, others had bolts. You say in your post that you have the new one, so I hope you can identify it once you look on the throttle body. If you have misidentified the valve and it is a different engine, there is another switch that works with the idle, but I will not be able to give you any more detail (if needed) until Monday when I can check my manuals. Post if you need more detail then. Good Luck.
#3067 of 3299 Re: TOD problem and speed sensors [wheels13]
Aug 29, 2006 (1:33 pm)
I have the same issue with my 2001 Trooper. The guy at Isuzu gave me three error codes when it was scanned. If I am correct Error code 13 and 14 was the front wheel speed, 24 was the rear wheel sensor circuit. There is a specific code for either the front or rear speed sensors. He is telling me I need to replace both! I have a hard time doing this as he too is quoting me $350.00 a piece and $450.00 labor. Unfortunatley I haven't found anyone who can validate the findings. Only Isuzu has the equipment to read the TOD error codes.
#3068 of 3299 Re: Idle Air Control Valve [atfdmike]
Sep 01, 2006 (3:52 am)
Actually my engine is a 2.6 "fuel injected" with a manual transmission. Do you have info on this engine? Thanks
#3069 of 3299 Re: Idle Air Control Valve [waterman2]
Sep 06, 2006 (2:58 am)
1993 Isuzu Truck Pickup (4WD) L4-2559cc 2.6L SOHC (4ZE1)
Vehicle Level Powertrain Management Fuel Delivery and Air Induction Auxiliary Air Valve (Idle Speed) Description and Operation
Description and Operation
Provides a means for increased idle speed when the engine is cold.
At the front of the intake manifold.
OPERATION AND CONSTRUCTION
The regulator allows air to by-pas the throttle valve, thereby raising idle speed. The regulator contains a temperature sensitive electric element that causes the air bypass to close gradually as the engine warms up. When the engine has run for approximately five minutes, the valve should be fully closed.
The air regulator is energized through the fuel pump relay and not directly controlled by the ECM.
1993 Isuzu Truck Pickup (4WD) L4-2559cc 2.6L SOHC (4ZE1)
Vehicle Level Powertrain Management Fuel Delivery and Air Induction Auxiliary Air Valve (Idle Speed) Specifications
Resistance 45 - 50 ohms
Here is a link to a photo of your engine and location:
Hope this info helps!
#3070 of 3299 Re: TOD problem and speed sensors [yorosco]
Sep 06, 2006 (3:20 am)
You may be able to find an independent mechanic with the Tech 2 tool and Isuzu adapter so that he car read codes. The TOD codes are in the powertrain module, which is easily accessible through the Tech 2 (which is what Isuzu dealers use).
The trick is getting the codes read right from the powertrain module. The sensors on the transfer case are fairly easy to access, so I cannot imagine why the part or labor is so high!!?? except that it is a dealer!
The 13 and 14 codes you refer to I am not sure of, but the 24 code is for the brake pedal switch circuit, and the ecm turns off the transfer case solenoid (electromagnetic coil which energises the clutch pack) if it see the brake is applied while the TOD is in action. It does not set the check light but does store in the memory when it is malfunctioning.
Hope this information helps. One guys opinion.