Replace.. or NOT Replace

At 60,000 miles, my '99 Isuzu Trooper (3.5 L V6) has died and requires an engine transplant (frozen left cam). Only now have I heard about the string of problems with the 3.5 power plant which is a Honda-GM (mis)marriage. Although the problem was fixed by '01 the Trooper was dropped after '02.



Is a ($3.5K - $4K) replacement worth it? Every other function of the car has been reliable and body’s in VG condition. With all those bad engines on the market, what are my chances of getting a ‘good one’? Or, Is this a total write off? The cost of repair is more than the trade-in value.



Would like your thoughts.

Personally I would write it off unless you have some strong attachment to it.

$5k-10k can you get a great used SUV with searching due to market conditions.

Well, first off GM and Honda had nothing to do with this engine-- it’s all Isuzu, though the automatic transmission is a GM model made in France. The problems with the 3.5 were mostly issues with high oil consumption and noisy valves, but both were generally benign so long as the owner kept the oil topped off. Of course, that’s a big “if” and a lot of them did get run low or out of oil so, yes, some more careful than usual engine shopping might be in order.

I’m curious about the diagnosis on yours, though. This is an overhead cam engine, so they should just be able to change the left head without too much trouble. And it’s a non-interference engine so even if the timing belt broke it shouldn’t have hurt anything. A complete new head isn’t cheap, but it’s a lot cheaper than a whole new engine-- are there other issues as well?

It was taken in because of a sudden, very rough idle and after all the “simple” explainations were discounted, my mechanic had determined the timing belt had hopped and so started the teardown. When the belt was replaced and set to crank, he said the engine wouldn’t move due to the left cam. They removed the head and saw that it needed rework, took a look at the right side and said it wasn’t far behind. He would re-do the heads but told us he wouldn’t drive it anywhere except around town. A rebuilt engine was the next option; a little more expensive but he thought a better way to go. He doesn’t do engine replacement so he wasn’t making out on the deal. This is a case where the repair equals the value of the car.

It was a used car and while it experienced oil loss (and had the noisy valves), the worst I ever had to do was put in 2 quarts. It was never run dry. I can’t vouch for the previous owner. It was driven less than 5000 miles per year and although it got one oil change a year, I used synthetic. Anyway, when I Googled Isuzu engine problems, I was astounded at how many similar cases with '99 - '00 Troopers and usually around 65K to 80K miles. It doesn’t leave me comfortable with the whatever engines are out there. The rebuilds are most likely recycling the same problematic engine. What’s your experience with rebuilds?

How does a cam that was turning (the engine was running) sieze merely from being set in time?