I also have a 94 Trooper SOHC that ticks. I wouldn't call it knocking, more like a tap tap tap. I think it started around 100k mark. What's worked best for me was switching to a 5-30w high detergent oil. I'm at 131K now and it runs strong, and only taps for around the first 30 seconds of running, and sometimes not at all. I live in a cold climate and the temperature plays big role in when it taps and when it doesn't.
Also note that it took a few oil changes to see the full benefits of the lighter weight oil. I would recommend doing a motor flush to get the gunk out, then do your oil change.
After all the reading I've done on this, I think this is just a bad design on Isuzu's part, and doing more frequent oil changes with a light weight oil is the only reasonable way to keep the problem in check. But I'm not a mechanic, just letting you know what has worked for me. Good luck.
To: 4th Nov 2007, 10:21.
Over the years, when I ran across an acceleration problem after a visit to a mechanic, the culprit was... the dad-gum mechanic. In every case, the worker had knocked a vacuum hose loose, or split a hose so that the vacuum was lost. Many of the cars I have owned used a vacuum signal to adjust the fuel mixture, or advance the spark.
I am not sure if this is the source of your problem, but it seems like a good mechanic would have noticed this and fixed himself.
I wonder if he lost the mark on the timing belt while trying to replace the tensioner?
Hi- I have a 92 Trooper and have been the sole owner now for over 14 years. It had about 400 miles on it when I bought it new in Texas. At about 60,000 miles I started to hear a very slight tapping noise and knew from past experience it was a "lifter". I reported it to Isuzu dealer in MS and he said it was "nothing". Well, we changed to synthetic oil - Mobile 1 and used it for a few years. It became ever expensive and in the end the noise became louder and more prominent. Took it twice to two different shops for estimate of repair. It would cost me over $2800 to get all 24 "lifters" replaced and new cam. I said NO!
I have made the oil changes regularly and have changed back to 10W30. Still have the noise which now sounds like a loud sewing machine, but I have 192,000 + miles on it now. Now I am ready to start repairing the engine since everything on it - the body that is, is still so like new. The 4WD is excellent. Any suggestions on the repair of the lifters like does anyone know if enlarging the oil jets would be fisable?
I own a '92 Trooper, bought it with 130K and now has 190K. Everyone I've spoken to with a Trooper gets the lifter noise eventually, as mine did. I used a motor flush additive before changing the oil the first couple of times and am using Castrol 10-40 For High Mileage Engines. It definitely responds well to fresh oil, in fact I never keep a log of mileage for changing, I just change it when the ticking tells me to (which I think is around 3 to 4 thousand miles).
It is getting worse, though, more and more frequent and often when the car is already warmed up and going.
I also changed the timing belt with tensioner (it was the 2nd belt for it) at around 165K. It does sound like it's going to come apart at the seams when it starts to rattle, you'll know it without a doubt. Mine cost $1100 at a mechanic, but also included complete overhaul of the cooling system just for grins since everything was off anyway.
Otherwise, the Trooper lives up to it's name, a trooper. Very reliable, safe, can climb a tree in 4-Low, very roomy and comfortable. I love it.
I purchased a 1994 Trooper S with 184,000 miles on it. I had to replace the shocks and do a tune up on it, but other than that, the only thing is the lifter tapping. I believe that part of the noise is the timing belt tensioner too. I will be replacing the timing belt, tensioner, and probably the valve pucks really soon. Maybe there is a better designed valve puck with better quality metal that is available. I am lucky that I can do all the work myself and it will save me a large amount of money. Other than that, it is in perfect condition.
Did my cam belt last year after water pump failed dramatically.
Sod to do and get right. Lining up the marks seems easy at the time but I've doubts now that one cam didn't get rotated round. Runs OK ish but falters a bit and does about 10 to the gallon. Otherwise a great solid car.
I have a 1996 Honda Passport, which is pretty much an Isuzu Rodeo. I have 240,000 miles on it. Bought it when it had 110,000 miles on it, and when I bought, it had a little lifter noise, but I took it to my mechanic and he said don't worry about it, it's not a problem, they all make that noise after awhile. I use 10w30 mobil1 full synthetic and it hardly ever makes that noise unless it is really cold outside, then it usually quits once it warms up. The engine has never been rebuilt. Everything on this vehicle works as it should, and the vehicle still looks almost brand new. I just ignore the noise; it's a small price to pay for such an excellent vehicle.
I have a 94 Isuzu Trooper with 149,000 miles on it purchased new, and a 1996 Isuzu Rodeo with only 12,000 miles on it. Both vehicles run great.
I did have some valve tapping noise for a short time in both vehicles, since they are exact same 3.2 engines. I keep the oil changed on a regular basis, and even use an oil flush from time to time, But what really made all the difference, stopping the tapping and making the entire engine run smoother, was the fact that I started using what is called MARVEL MYSTERY OIL, ADDING IT PER DIRECTIONS TO MY OIL AND GAS AND EVEN TRANSMISSION.
It really works, but be careful it does swell O rings, so keep it out of your brake fluid, but it does swell the rings in your transmission which is good. This Marvel oil has been around since the 50s and it will increase your gas mileage and cleans your fuel injectors, makes transmission quite leaking and makes it shift smoother, and makes your engine PURR.
I have even witnessed in a 80 Cougar when the transmission went out, and needed a new one, our family mechanic drained all the fluid out of the transmission and filled it with this fluid, and let it sit for 5 days, and slowly running the engine and shifting it so the fluid was able to enter all areas of transmission, and it finally swelled the rings, and they drove that car for years after words, this is a true story.
Try it, it is a thin slick fluid and does not break down easily, you will be amazed, just do not get carried away, READ THE DIRECTIONS FIRST. I LOVE my Isuzu's.
GOOD LUCK, HUNT.