I've got a 99 Trooper 3.5 L Auto w/ TOD at 135K and it's knocking like nobody's business! Found an 01 3.5L w/ 50K. Everything I've read says it should be a straight swap, the 01 is block and heads, no intake manifold, exhaust manifold or accessories. One thing I noticed was someone mentioned the #6 plug coil is different between 99 and 01, will I have to use my valve cover off the 99 to get the plug coils to fit correctly? Also will my intake and exhaust fit the 01?

I know 98-00 were the big oil users(hence the knocking), I've read that 'zu fixed this in late 01 with more drain holes in the pressure rings or something, is there any truth to this? Or am I going to replace my 99 3.5 with this 01 and get the same problem in another 50K?

Thanks for the help, great forum!!

Unless the engne has the screw in PCV it won't have the larger oil drain back passages (i.e. it will have the same oil burning potential).

The #6 coil is different in my 99 than the other 5 coils so that it can clear the brake booster. I suspect, but don't know for a fact, that it is the same for 01. Try using an online parts catalog to see it the part numbers have changed (http://www.myisuzuparts.com/sitemap.php). In fact the catalog should answer many of your questions as will doing a search on the site. Pay particular attention to Jerry Lemond posts as he is a true Isuzu expert.

FWIW, my Trooper has never burned any oil. Many other people that keep their oil, pcv, and egr clean report similar "luck". Others routinely use Rotella and/or occasional seafoam treatments to reduce oil burning. Again a search will pull up many pointers.

It could also be that this is all overkill and you simply have a bad tensioner. Bad ones do tend to tick and many people have been fooled into thinking they were about to lose an engine. Again search is your friend.