Isuzu Owners Maintenance and Repair



  • oldgoat3oldgoat3 Member Posts: 4
    jason dont do a half assed job use full synthetic mobile one i have been in very high level race shops for a lot of years and there is nothing that will give you more bang for the buck than mobile one. better gas milage, a ton of miles more longevity all major help to the motor and go with mobile one for the tranny as well. blends are a joke because the part that is not full synthetic just reduces what is to a level of non. if you get my meaning. and there is no other than mobile one. i have seen the results there is no subsitute
  • julyapriljulyapril Member Posts: 2
    Recently my 1999 trooper (automatic, diesel 3.1L) is not working properly. The problem is the gear is shifting smoothly from 1st gear to 3rd gear but was unable to shift to 4th gear. The speed will stay constant at 80km/hrs at 3rd gear. I have consulted a few mechanic, it seem that i'm getting a few opinion for my problem.

    My second concerned is what is Torque on Demand? and how it functioned? Is it something link with ABS or ECU? I'm really confuse on this TOD system...Please Help!!!!!!

  • julyapriljulyapril Member Posts: 2
    Dear all
    I am in a miserable situation. Recently i bought a 1999 isuzu trooper with TOD function which i have no idea on it. Anybody can help me to understand about this TOD.
  • desimonesdesimones Member Posts: 18
    I have a 2000 3'.Trooper. TOD allows you to select either 'Power' power down shift (for hills or towing, or a shift up for 'winter' or slippery roads. You can select either (power/winter or neither), by the console switch near the shift lever.
  • atfdmikeatfdmike Member Posts: 414
    Simply put, it is a traction sensing system. It monitors wheel speed via sensors on the Transfer case, and when is senses a difference in wheel speed between the front and rear wheels, it transfers power to the front axle until speeds match. It is a little more complex than this, but that is the basics, as I understand it.
  • reptileguy777reptileguy777 Member Posts: 2
    I just finished up a head gasket job on my trooper. Not the 1st head gasket I have ever done but boy what a pain in the butt. But here it the issue it starts up and runs great for about 30 seconds then it shuts off. If you stay on the gas it will stay running. It acts like a vacuum leak but I cannot find any. The check engine light comes on once in a while. The book had me check all kinds of crazy stuff I am at the end of my rope with this can you please help.

    Thanx Josh
  • atfdmikeatfdmike Member Posts: 414
    Sounds to me like maybe you have a vacuum leak OR maybe you need to check the routing of the vacuum lines? Again? How about the EGR...I think yours is electrically the connector in it, and is the gasket OK and the two bolts tight? Just basic stuff, I know, but easy to check. I think the fuel pump is shut off if oil pressure is too low, could that be a problem if yours is low? That might also explain why it will stay running when revved. Have someone else keep it running while you examine the engine while it is running...just be careful. HTH
  • reptileguy777reptileguy777 Member Posts: 2
    I will definatley check that. The EGR seems to be operating fine it has no electric to it but I did not check the gasket. Also what exactly does the box that one of the EGR lines go into. It is next to the ignition coil and it has electric and 2 vacuum lines?
  • tkem12tkem12 Member Posts: 5
    Could I get some info on the oil filter upgrade. My 2000 Isuzu Trooper uses a Qt every 700 Mi .I can use all help I can get.
  • tkem12tkem12 Member Posts: 5
    I sure could use some info on this oil filter update for my 2000 trooper that is a oil hog.... 1 QT per 700 mi
  • atfdmikeatfdmike Member Posts: 414
    You are experiencing a common complaint with the 3.5 L engine. You need to use a good oil high in synthetic Rotella. It will clean the piston rings and drains over time that get gunked up and cause the oil to leak into the combustion chamber and burn off. Patience is may help but it does take time. Some claim that using Seafoam will speed it along. HTH
  • pwebsterpwebster Member Posts: 1
    Can anyone tell me how I'm supposed to get a wrench down in the small opening to remove my old spark plugs? Do I need a special tool for this?
  • atfdmikeatfdmike Member Posts: 414
    A standard size spark plug socket on an extension should work fine. The spark plug socket does need to have the rubber insert that will hold the plug while lifting and lowering it into the tube. Depending on your model vehicle, a universal joint may help if you cannot get a straight angle at the plug tuve.
    A deepwell impact socket will not work since the walls are thicker, and the spark plug is not held in place correctly with one. HTH
  • waata99waata99 Member Posts: 1
    Where are you located?
    Can you give some specifics about the Trooper and what you're looking to get out of it...
  • wlbrown9wlbrown9 Member Posts: 867
    Second what atfdmike might need a set of extensions especially for the plugs closest to the firewall. If you have trouble with the rubber boots between the plugs and coils being stuck on, use compressed air down the center hole to pop them off. Before I got a real compressor, I used one of the little 9 volt pumps and it just broke the seal without a problem.

    If you don't have a socket with the rubber insert, one of the magnetic extensions would work to remove the old plug once it is loose, but it would be much easier with the real spark socket for getting the new plugs started. Remember these are aluminum heads....don't want to get them threaded incorrectly.
  • desimonesdesimones Member Posts: 18
    I heard that a faulty oxygen sensor can decrease the fuel efficiency. My engine check light on my Trooper goes on periodically and was wondering how I can tell if this is the cause. Does anyone know where they are located. I believe that it has two sets (4 total).
  • atfdmikeatfdmike Member Posts: 414
    Hi, two are located before the converters, one on each, and two are located after the converters. The ones before the converters tell the ECM when to go from closed loop to open loop, and thus do affect mileage if they are not working properly. The heaters built into the sensor just help the sensor work faster as it shortens the time needed for them to get to proper operating temps. The ones after the converter act as a comparison for the ecm to tell it if the cats are functioning properly, but do not directly affect engine settings. The sensors before the converters are the most likely to cause problems but either set can set a code.
    Get the codes read....the OBD system has the capability to tell you which sensor is causing the CEL. Hope this helps. One guys opinion.
  • tkem12tkem12 Member Posts: 5
    On Feb 23,2008 desimones talked of a oil filter upgrade that replaces the oil filter housing to accomodate a larger filter THIS IS THE INFO I NEED.
  • davec4davec4 Member Posts: 8
    I have a 2000 Trooper. My serpentine belt fell off due to the alternator being loose. Can someone send me a diagram of it's path and any special instructions I might need in putting it back on?

    Thanks in advance!!!
  • desimonesdesimones Member Posts: 18
    Most 3.5L Troopers appear to have this problem. About four years ago I found some info on replacing the oil filter plug and installing a larger filter (V6 Ford Ranger PH8 extended mileage type filter) on my 2000 Trooper LS. This adds about another 1/2 qt. to the oil capacity and should help reduce heat and improve circulation. I also started using Mobil synthetic oil (recently upgraded to their new Gold synthetic). The new filter is more than twice the size of the old one and with the oil change, I now burn less than half the amount of oil (approx. 1 qt. every 3-4 months). Like a previous member had stated, it will take about one change cycle before you notice a significant improvement.
  • bahmedbahmed Member Posts: 66
    just search isuzufaq in your favourite search engine or go to the website of the brand gates
  • matausmataus Member Posts: 43
    Hi Everyone!

    I'm not sure if anyone will have the info, but I am thinking about swapping out my engine on my 1990 Isuzu Trooper 5 speed 2.8 liter v6. I want to do so because i have about 190,000 on the engine, and the power has diminished greatly thru the years. My 1990 Trooper is in mint condition, and I don't want to give it up. Not just yet anyways.

    I guess I am asking what route to go. Will rebuilding the engine be the way. I would like to maybe throw another engine in, but its difficult to find anything out there with lower miles on it. Is there maybe another engine out there which will work in my 90 Trooper? Another engine with more horsepower?

    I have never rebuilt another engine before, but swapping engines/transmissions/ etc... have never been a problem for me.

    If there is anyone out there who can help, it would be greatly appreciated....

    Maddy... :confuse:
  • atfdmikeatfdmike Member Posts: 414
    Hi, The 2.8 is a GM engine and very reliable but very underpowered, which is why they usually go a long way. The GM 3.4 engine is a direct replacement , and the 3.1 was also available. Most swappers go with the 3.4........more HP and still very reliable. You may have to swap the computer along with the engine, but I am no expert on this as I have not done it. I did rebuild my 3.2 DOHC, and it ran me about $1500 to do it, so a swap is within reason if you know you have a good engine to swap in. HTH
  • matausmataus Member Posts: 43
    Hey there Mike. You gave me some good info sometime back concerning a stalling problem I had. I had come to figure out that a wire had been waring out on my fuel pump. I did go ahead and dropped the tank and replaced the pump. Problem resolved.!

    As for the engine replacement, Would I need to find the same year engine as my 1990 5 speed manual. Sounds like the 3.4 would maybe be the way to go. Do you know what other vehicles that particular engine would be in? I love the Trooper I have, but it gets to be more difficult to get up the mountains here in Colorado.

    Thanks for all the info...

    Maddy ;)
  • desimonesdesimones Member Posts: 18
    About a year after purchasing my new 2000 trooper, I removed both rear seats (since my primary use was more utility/space than a passenger vehicle). I am now in the need of replacing both rear seats, but am not quite sure how they re-install. I have not ben able to find any heplful info on this process. Does anyone know where I might be able to obtain this info?
  • atfdmikeatfdmike Member Posts: 414
    Did you try going to and looking up the info on your year Trooper. The different image illustrations would give you a good idea of what hardware has to go where to reinstall. HTH.
  • puzzled4puzzled4 Member Posts: 2
    I put 3 qts of oil in the trooper when I noticed the oil light. This 2002 trooper has never used oil before. I did a few errands and went home. A few hours later I was driving and a noise started. Checked the oil and it was gone. Put 5 qts in and the noise is still there. This trooper has been an excellent truck. Does anyone know what the problem could be?
  • atfdmikeatfdmike Member Posts: 414
    sounds like you hve the 3.5 liter engine, which is known to be a real problematic engine with oil consumption. Usually it comes on gradually, the result of the oil wiper rings on the pistons fouling and not working properly. Isuzu fixed that condition in later engines, but getting them to address it when the vehicle is out of warranty is pretty had to do. You have to start there though, I think, in order to see if or what can be done.
    Since yours seems to have come on suddenly, might be something else going on, but it is obvious it needs to be looked at NOW>>>>>>>> before the engine destroys itself. Find a good mechanic even if Isuzu wont help. HTH One guys opinion.
  • puzzled4puzzled4 Member Posts: 2
    Thanks. Our warranty is 100 000 miles so we still should be covered. Isuzu replaced the head about a year ago because of a recall. It was warped. We had no idea there was a problem with Isuzu engines til now. Thanks again.
  • belaircarguybelaircarguy Member Posts: 107
    I have a 1996 Trooper with the gear shift type of 4 wheel drive (no electronic buttons on the dash). When shifting into 4 wheel drive (either hi or lo) everything is fine if I shift into 4WD when the vehicle is cold. I can do this when I first start up, and all is OK. If the Trooper has been driven and is warm, the 4WD will not engage. The dash light (4WD indicator) works fine and when engaged it lights up (green) and when not engaged it is off. When it is in 4WD the system works great.

    Unfortunately, this is a problem, as I drive the Trooper a couple of hours from home to a mountain cabin, at which point I need the 4WD to navigate the road. I had to let it sit at the base of the mountain, and get a ride with a buddy up the hill. Came back the next morning when the car was cold, and 4WD worked! I have tried this a number of times with the same result - warm - no 4WD, cold - all OK.

    Any help would be greatly appreciated.

  • 03Bob03Bob Member Posts: 4
    I also have a 1996 trooper. Same problem. Driving me crazy. As of this post I am still looking for the cause & trying to fix it. Have you made any progress?
  • 03Bob03Bob Member Posts: 4
    The latest: I believe I have found the trouble. On the VSV there are 2 switches, blue & gray. remember the 4WD works when cold, as the engine warms, the gray switch is closest to the oil pan. As heat radiates, it warms the gray switch. I got brave and took it completely apart. The metal slug inside the plastic housing was binding in the bottom of the bore. I used a drill to clean the sides as much as possible. still binding. Calipers measured the slug and I reduced the diameter about .010".
    I used a collet on my milling machine to hold the part while gently filing and scotch briting the part. reassembled, applied power and it now clicks when power is applied.
    next step is reintall on trooper. I am running on the premise that if the switch will not function w/ power, the vacuum can't get to the right place. After lunch, I will find out.
  • belaircarguybelaircarguy Member Posts: 107
    Not sure if you corrected your problem with the 4WD, but my trusted mechanic had to contact the Isuzu dealer and together they surmised that a solenoid assembly was not working properly. The part was $260 at the dealer. Once this was replaced, the 4WD has worked perfectly - cold or warmed up. Apparently, even though the Trooper has the floor levers to engage the 4WD, rather than the newer push button variety, it still is an electronic switching mechanism.

    All is now well with the Trooper.

    Hope yours is working correctly also.
  • 03Bob03Bob Member Posts: 4
    Well, the repair did resolve the problem. I now have 4WD when I want it. WOW.
    I saw the part on Ebay, $179. I did not check with a dealer. The 4WD engages as it should, hot or cold. While I was at it, I figured this would also be a good time to drain & refill the differentials and the TOD(torque on demand) (thats where the fork slides a gear over the 2 shafts and makes it drive the front wheels) Switched to synthetic oil as we get some cold days here in the Northeast. Responds better when shifted into 4WD.
    Not to bore you w/ details but.... the 4WD lever mechanically engages the transfer case and apparently it also sends a signal to the VSV(vacuum switch valve) that moves a diaphragm/shaft/fork assembly, routing the vacuum to the proper side to move that fork in/out of 4WD. I did purchase the shop manual for this rig, hence the long explaination. There you have it.
    Glad your trooper works too.
  • fixeditfixedit Member Posts: 2
    Yup, same old problem. After the pain in the Donkey replacement of fuel pump which was not needed!!! But in this case it was a good thing because the filter had fallen off.... but I have hot wired it, which now I know is the FIRST thing to do, and it works fine. So I was sure it was the oil level and yes it was 2 quarts low, but now it is at full and still pump will not work except when starter is engaged, so it starts and then cuts off. Now, I can't find my manual and don't remember where the oil sensor that sends the signal to allow the pump to work. it is a 1998 2.8 and I love it!! I even swaped engines with out a manual, Yea, So this is such a minor problem and very frustrating. I am about to hot wire direct to the ignition but want to know if it will hurt anything. Does the pump work all the time ? Does it have a pressure shut off? From what i can tell it simplu has a pressure relief valve on top of the pump but I don't want to burn out the motor since it is such a pain in the Donkey to drop the gas tank!! I think the nextrt time I'm going to cut an make an access pannel. I truely think it will take less time. I'm also pissed because the two bolts on the same side that hold the protective cover sheared off.. guess I have to weld something together. Well, If anyone has a manual for this year or knows about the pump electrical system please give details or email me with them at [email protected] Thanks and Blessing to all.
  • fixeditfixedit Member Posts: 2
    Not sure if this will help but be sure it is not in 4WD!! It is not supposed to go over 45mph I think. Just a thought. Also, I have slowly realized that it is ok to run the rpms up.I have a 4 banger and it loves to be run at 3k and higher. When I have been towing very heavy stuff up hills and mountains I always down shift right at 25k rpm and it will rev to about 35k.. just let it wind happily along.... However check with others about the v6 motor... I din't know they made a v6 that was so small?? my 4 banger is a 2.6 and kicks butt, with great gas miledge!!! The best work vehicle I've ever had!! Just a pain in the Donkey to work on!!!!
  • tkem12tkem12 Member Posts: 5
    It could be the theft deterrent circuit. Your key has a chip in it,if the resistance is high / low or the reader is bad the engine will shut down after a few seconds.
  • margaret3000margaret3000 Member Posts: 1
    Recently had the transmission slip issues and took it to a transmission place who told me the transmission was full or fluid and when the opened up the pan there was a ton of metal. He rebuilt my transmission replacing a pump and other necessary parts. Took it home where the temperature light went on. I stopped the car it was dead. They shop took another look and said it was a shift on demand issue, he repaired that. Brought it home where it ran like a new car for 24 hours then began to feel sluggish again. Now when I shut the car off the parking lights stay on if I lock it. I am not mechanical in any sense of the word!! Does this sound familiar??
  • delladarlingdelladarling Member Posts: 1
    I bought an 1995 Isuzu Trooper and it is missing the owners book and I would like to find one. Can someone help me.
  • surgicalsteelsurgicalsteel Member Posts: 1
    I was wondering how much of a pain it is to remove and replace the spark plugs on a '96 Trooper with the 3.2 V6. I took it to a mechanic just for an inspection and they recommended I R&R the spark plugs, but they want $250 just for the labor, because it's "a lot of work, you have to practically take apart the engine." I've done spark plugs on other cars and know this isn't the case, but I also remember trying to do it on my trooper many years ago and the rear driver's side spark plug was a big pain to remove because there is something blocking the path of a screw driver or socket. I'm pretty sure I'm being fleeced, but is this actually normal for this particular model? If not, does anyone have any tips on getting that rear driver's side SP out? Thanks.
  • jjmcdadejjmcdade Member Posts: 5
    I had the check engine for a while until I had the spark plugs and wires changed, I tried everything else before I did that with no luck. Hope that helps.
  • lilshelplilshelp Member Posts: 2
    So, I've always wanted a Trooper-it's my dream car...really I've always wanted an older 2-tone one, but a '95 w/ 186k is what's available. They are asking $2,200, I know nothing of what to look for, I don't know if this was a good year for Trooper's or if there were a bunch of problems....I see hardly any posts on here about them...any suggestions?
  • jaypizzthebizzjaypizzthebizz Member Posts: 16
    I need to pay more attention next time it happens. I don't think the wheels are spinning. The revs are going up, either without movement or with less movement than you would expect given that the revs jump up to 2500-3000 RPM pretty quick. It's almost like the engine is getting ahead of the transmission or something. I thought the fluid level check was with the engine running, but I didn't remember anything about the "trans in Drive" requirement. That's not how I checked it last time; maybe that meant my reading was off?
    You never should check the fluid in drive there is no reason to the only requirement is that the tranny is hot and the engine is running it makes no difference what gear your in how much fluid will register when checking it only different levels when coldor hot and or running or not running this insane what if you ran your buddy over cause he's checking the fluid and you have it in drive n something happens lol 
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