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I recently bought a 95 Isuzu trooper V6 gasoline engine with valve lash noise. Previous owner said there was a problem with sensitivity to varnish formation on that year, and was corrected later. He removed and cleaned all lifters, but did not replace. I would repalce the lifters, but its a major job to get to them. He has been running Mobil 1 synthetic.

Questions: 1. Anyone with personal expereience with this engine or this issue?
2. Would a more agressive diesel oil such as Rotella T or Delo or Delvac clean up the lifters?

kcj
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I, too, have a '95 trooper with noise. Mine is a 95 LS w/ a five speed. The engine is the sohc 3.2. The noise is from the cam followers and rocker arms , which open and shut the valves. Some call these lifters. They clog and flatten out over time. Isuzu says it's due to infrequent oil changes. My experience has been different in that my oil has been changed faithfully in excess of the manufacturer's specs for the life of the vehicle. I've been running amsoil synthetic since 50k and now have 125k. I have replaced a couple of followers already. I'm going to replace the remainder of the cam followers at the end of the month. I should have done them all at once. Some strategies I tried to put off the lifter replacement: Switch to a light weight synthetic -- 5w30 or 0w30. Heavy oil may make the noise go away temporarily, but it exacerbates the problem over time. The root cause seems to be oil passages that are too small -- sort of like clogged arteries. I have also heard or read that the cam lobes may have been manufactured with a less than ideal alloy, which causes a reaction over time that results in the followers flattening out and thus sounding like you just bought a deisel. I also used various engine cleaners like rizlone, BK products, amsoil's own cleaner. They were temporary, at best. Once the knock is with you, it's not going away until the lifters are changed. When I replace the remaining followers in May, I'll be interested to see the state of the two new followers I put in about a year ago -- my question being, does replacing the them fix the problem for good, or for how long?

Good luck. Let me know what you do. I'm stuck with my trooper for a while because I just bought a new(er)honda. Nothing else has given me trouble on the trooper, so it's a small price to pay for such a faithful goat.

BigFish
Last edited by bigfish
I have the 92 trooper with 3.2L SOHC, and the ever ticking valve noise.
I tried every additive, treatment etc. with no luck. It would come and go.
Last resort was a procedure in the ISUZU TSB, changing to Mobil 1 0W-30 Synthetic. No luck, lifter still ticking (this is a very loud noise and
makes driving a very unpleasant experience.) I am now in the process of
the hydraulic lifter cleaning procedure detailed in the ISUZU factory TSB
on this subject. This procedure is no quick and easy project. Set aside
at least a few days, more like a week, especially for the home mechanic.
There is a LOT of stuff to take off the engine BEFORE you can even get to
the valve covers. YES you will have to pull both cams, and all rocker shafts, then carefully disassemble each rocker and each lifter individually
cleaning all oil passages very carefully. Especially the rocker and the
shaft. These have very small oil passages, only slightly larger than a paper clip in diameter. Mine had numerous clogs in the rocker arms and rocker shaft oil passages, even though only ONE lifter was noisy. ISUZU
says the hydraulic lifters are NOT available separately and must be purchased along with a new rocker arm. The tiny "O" rings on the lifters
also are NOT available separately from ISUZU, so be verrrry careful with
these. While all this is disassembled, there are many short rubber hoses
that cannot otherwise be reached. Replace all. Also you will need a new
timing belt, and the tensioner and idler pulley, and a new water pump too.
New radiator hoses won't hurt either. Get LOTS of spray carb cleaner and
a gallon pail of carb cleaner for soaking the lifters. Steam clean the
entire engine BEFORE starting anything. I have about $500. in parts. I can
now plainly see that no additive of any kind would have ever cleaned these
oil passages and lifters.
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