By on August 28, 2013

Keith writes:


I am facing a problem with little real consequence, just more looking for advice.  We have a third vehicle, one that isn’t really used much and was purchased for $1400 a couple years ago to serve as a backup when/if one of our primary vehicles was out of service (A 2005 Pahtfinder with 130k miles and a 1998 Rodeo 4×4 with 235k miles).  It’s a 1999 Isuzu Trooper 4×4 with about 190k miles on the clock.  Other than burning oil there really wasn’t anything wrong with it.  Everything worked and to be honest my wife liked driving it much more than her everyday car. 

That being said, after changing some dry rotted belts and hoses I decided to take a look at the timing belt to make sure it looked ok.  After pulling off the cover it was badly deteriorated.  I employed my father in law to try to change the timing belt.  Long story short, we were off on the timing and think the heads are now ruined.

I am considering replacing the heads (about $350 a piece online) but I have also seen longblocks on ebay for $1200 to $1400 as well with less miles than mine.  What is the better way to go with this?  A junk yard engine or just put some remanfuactured heads on the existing?

I know the heads are the easier fix, and this vehicle really isn’t anything we depend on, but it is nice having a third car.  I also am weary of buying a junkyard motor as there’s no telling how long it’s been sitting.  There is always the option of getting another craigslist car but I spent a lot of time finding a decent one and I don’t feel like scouring the dregs of Houston craigslist to find another decent deal.  If I replace the heads I may consider doing an in-car rebuild to replace the piston rings as well.  It’s basically just a weekend project car right now and my kids can learn a little while I work on it.

Sajeev answers:

I wonder what people outside of Houston think about a three car truck household. Such is the joy of living in the flyover states, in a gigantic cow town more diverse than New York City.  A land where all people enjoy the Body-on-Frame lifestyle!

Or not…but I digress.

I think you are on the right track, replacing the heads is the cheapest fix.  There’s (probably) nothing wrong with the short block after a timing belt fiasco: take a borescope (make sure it fits thru a spark plug hole, some cheaper models will not) and check the piston for cracks/holes.  I suspect the valves are messed up and nothing more.

Once the replacement heads are in your garage, get a complete gasket set too. This is ensures everything is freshened from the head gaskets all the way up to the fuel injectors and throttle body! Why not make the motor 100% sorted if you’re going to all this trouble?

You seem to like this rig;  it is a Trooper, after all. Go ahead and do it right this time.


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32 Comments on “Piston Slap: Such a Trooper!...”

  • avatar

    I’ll wear the black hat; I think it’s nuts to put any money into a 14 year old Isuzu, bent valves, cracked pistons or not. I’d fuggetaboutit!

    If you want a used SUV as a third car that will go the distance, buy an old XJ Cherokee, or a Pathfinder, etc. That Isuzu will be nothing but a continual headache and a cash drain.

    • 0 avatar

      As a former Trooper owner, I can tell you that the Trooper is a much more enjoyable vehicle to drive than the Cherokee; the interior ergonomics make the Trooper very comfortable, and the low belt line and thin A & B pillars give visibility unlike anything you can buy today.

      The Trooper is a solid, well built machine that will go the distance with basic care. If all else works I’d definitely make the repairs and keep it in the family fleet.

      BTW, the lesson in this is don’t take on major repairs if you don’t know what you are doing; the consequences can be very expensive.

      • 0 avatar

        *Except for transmission problems, which are inevitable (if not already occurring) at 190K.

      • 0 avatar

        Toad – I have to agree with you regarding the lesson that has hopefully been learned. If you don’t know what your doing, don’t mess with it which is all the more reason for this Trooper’s owner to stop the backyard shade-tree mechanics now and at least get some help if his intention is to carry forward with it.

        That said, I have to tell you, I haven’t seen a Trooper in years. Isuzu has pretty much vanished from N.A.; not so much with the XJ which are still everywhere. Yeah, they’re a bit crude but 300,000 miles is common with a 4.0 I-6 engine and ditto with the XJ on Trooper-like visibility. Sure AMC/Chrysler/DC made a lot more of them than Isuzu did of the trooper but then there was a reason for that too.

      • 0 avatar
        Dave M.

        Seconded! My just-retired Trooper is one of the most willing and able vehicles I ever had. Very comfortable seats, superb sight lines, mountain goat. Cavernous capacity.

        My truck’s only frailty is transmissions….it is on it’s 3rd (only 1 paid by me) and I don’t want to have to do another for a long time (they last 70-80k on average).

        I did the timing belt at 100k, then again at 200k along with the water pump (preventative maintenance).

        I was always curious about the oil disappearance…there are never any leaks, and no noticeable burn, but it still takes a quart of oil every 1000 miles. Apparently its a Trooper trait.

        So….money and time well spent. Troopers are indestructible.

    • 0 avatar

      Too bad those old school “hardbody” Pathfinders are getting less and less common, the almost vulgar chunkitude and super 80s-ness is really endearing to me.

    • 0 avatar

      I had replied earlier but comment was lost?

      Anyways, an Isuzu Trooper is head and shoulders above an XJ cherokee or a 2nd gen+ Pathfinder as an all around SUV. Pathy and Xj have much less interior room, neither have body on frame construction, and both are just as susceptible to rot (Nissans are especially bad). THe XJ’s transmission and engine may be as rugged as they come, but most of the components surrounding them and the body are nowhere close to the Trooper in terms of longevity or build quality.

      In offroad circles, and particularly in the overlanding/expedition side of things, Troopers are seen as legit budget versions of Toyota Landcruisers (LC80, LC100). Massively beefy axles and suspension and frame. Troopers and Monteros just don’t get the respect they deserve from the layman car enthusiast, even though internationally they are recognized as awesomely rugged 4x4s

      Weak spots are they are very picky with timely oil changes, as I recall the pistons have oil passages in the ring land that get clogged, the rings stick, and the truck starts to burn oil. Also the 4l30e GM automatic isn’t as durable as the Aisin on a Cherokee, but rebuilds aren’t too bad.

  • avatar

    If it’s fairly rust-free and otherwise OK condition, rebuild the motor. Don’t go halfway with just heads.

    A junkyard engine will only have other problems.

  • avatar

    I am a fan of these but at 190K, I think it’s time to let ‘er go. I also agree with the other posters here to be sure you have an int engine and recheck your work. I had a 96 LHS that needed a belt. I checked and checked and checked before starting it. She started but once the belt settled, was off on tooth. Drove it like that for a week. Pulled it apart and realigned it and she still going to this day two years later. No damage. I would recheck before pulling the plug on it.

  • avatar

    I am just envisioning buying the gas for 3 old 4wd SUVs! Since you already have 2 trucks, why not dump the Trooper for (I know I hate even say this to a Texan) a car? But if that doesn’t work for you then I would definitely just replace the heads and save the money. I love Troopers though, on second thought I would probably keep that and get rid of the Rodeo. Can those engines be swapped??

    • 0 avatar

      I was thinking many of the Rodeos had a 4-cylinder. Either way, he’s got 3 really old, really poor MPG cars as you mentioned. I’d dump it. Every old Trooper I see has numerous issues.

      • 0 avatar

        I don’t know if 4cyl Rodeos were all that common. My memory is a bit fuzzy but I think I remember that they offered just the lowest base 2wd model as a 4-cyl, and then everything else was a V6. So a 4wd should be a 6, but even if I am miraculously correct, I don’t know if its the same V6.

  • avatar

    Seems like an ok problem to have. These things are reputed to last forever but in comparing them they don’t seem to have the towing capacity of some other SUVs and seem to top out at 19mpg. I think I would fix it and put it on Craigs list.

  • avatar

    Time to dump it and get an SLX.

  • avatar

    As a father of three boys, I say repair it!

    Your children will learn that it’s ok to repair tings rather than toss it aside once the first difficulty comes along. This is a useful skill later in life – marriage, jobs, and tools all can have issues that need repair rather than replace.

  • avatar

    Was the Pahtfinder the SS version?

  • avatar

    Generally, how does one install a new timing belt without it being “mistimed”? Are there any markings, do the pulleys go in a certain place? There must be some way that the mechanics know about or are all of them different?

    • 0 avatar
      bumpy ii

      Sometimes you do get marks and notches and the like. Other times, you mark the old belt and sprockets with a paint pen or sharpie, take off the old belt, transfer those marks to the new belt, and line everything up. The big thing is to make absolutely certain that the cams and the crankshaft don’t move out of phase at all while you’re doing this.

    • 0 avatar

      For a SOHC engine, the above is correct. For DOHC cam egines such as my long lamented Volvo I-5, there is generally a tool that you can use to lock the camshaft pullies in place so that they do not move. The compression of the engine will generally keep the crankshaft in place, but the cams need to be locked into place before you remove the belt.

      They generally recommend replacing both the water pump and the belt tensioner as well while you are doing the job, since a failure of either will cause the belt to break and screw the pooch.

      The Volvo was a piece of cake, simce the Swedish engineers really thought through the 850. My A3 2.0T, however, was a day and a half of labor I let the dealer so, since the front of the car and the radiator had to come out before even attempting the job. And yes, it had to go to the dealer, since no indie shop in my town wanted to even touch the job.

  • avatar

    I am all for repairing it, however if you had issue doing the timing belt are you up for a motor swap?

  • avatar

    SFVAR: You should have attempted it–the A3. I did our Audi A4 timing belt and I had literally no mechanics experience —since I had worked on my old Datsun 510 back in the 1990’s! The internet chat boards are full of guys that will walk you thru the procedures—just follow a DIY. Only requirement is a computer, tools and a set of balls. Repairing one’s whip isnt as hard as it seems–especially in the modern days of the youtubes and internets.

  • avatar

    Everyone is missing the point. His final first paragraph says his wife prefers to drive it. If Mama ain’t happy . . . Fix it.

  • avatar

    Some earlier comments seem to have disappeared into the ether…

    The Trooper V6s appears to be non-interference engines so a mis-timed belt shouldn’t cause any permanent damage – you may want to go back and double check your work. What makes you suspect head damage? Did the motor spin freely when you turned it by hand before you tried cranking it?

  • avatar
    MRF 95 T-Bird

    This should be an easy fix just get the service manual and reinstall the belt with the correct timing mark setting. Wonder if anyone has done a SBC LS1 conversion in a Trooper.

  • avatar


    That’s what I thought and read when I started the job and I have the shop manual for the 3.2L in the Rodeo and I have done the belt job in it multiple times. But after missing on the crank pully by a tooth or two and then resetting the belt and making sure everything was good I tried it again and it sounds like hell. I have all the marks right now and I even counted teeth but it’s still off. I haven’t taken the heads off yet to check them, work has been busy and I haven’t had the time to verify, but after reading up on it a bit the 3.5 in the 98+ troopers was a modified version of the 3.2 and the height change in the heads in the 3.5 make them more susceptable to bent valves with a timing problem. I will verify when I can get the heads off. Sorry for the late response, I have been out of town a couple weeks for work.

    I hope to make it a learning experience for the kids mainly. As for having three low MPG suvs, I drive about 3 miles to a bus stop, or about 20 miles to the airport most days. So not a lot of driving anymore, and the type of work I do bennefits from having the 4wd when I need to be on-site and both have been pretty reliable. They also work well for camping/ski road trips we take as a family about 4 to 5 times a year.

  • avatar
    Andy D

    I set the engine at TDC in #1 before I take it apart. The general rule is that if you start with the timing marks set correctly, 2 complete turns of the crank shaft will bring it back to the marks. Take the plugs out and turn the crankshaft with a wrench. If it fetches up.Stop.

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