They were putting a 4.2L in the trailblazers up until they stopped making them. I drove one for about half a year and really liked it. It was pretty quick for a big SUV (270hp 275 ft/lbs of torque). My mom owned it for 10 years before me and we never had any problems with the engine. It was also on Ward's 10 best engines list for a few years.
I was reading the other day that it was designed to be turbo charged. Think of the power it could make with some boost.
I had a Ford 4x4 truck with the I6 when I was in high school. It was a 4 speed with a granny gear, and had 5.13 gears. It had a twin, and they were special order farm trucks. It would pull a house off the foundation, but it would barely do 65mph going downhill with a tailwind. My XJ I6 ran great with 200k on it, and my Wrangler I6 will do the same. The GM 3800 V6 is another motor I've used, and it would run forever.
'02 TJ X Apex Edition
'00 XJ Sport
My hypothesis is two fold;
1)the pistons are different from 96-ish/97 although internal specs are the same. I think they went with a cheaper casting which leaves the piston inheirently weaker. Some of early powertechs didn't have teflon coating on the skirt, those that did they weren't as far down on the skirt as the others. Weaker piston/skirt material, with less/no teflon coating means more friction on a weaker material.
2) Now add in that misfire detection isn't the greatest (Im getting long winded as usual so I am not going to go into detail)
2a)and that CMP and CKP sensors tend to fade in and out on without going completely out of spec- just living on the hairy edge of the outer limits t on our rigs and only then ultimately going gonzo.
This all meaning the revolution algorythm of the misfire detection prgram gets eronious data, doesn't set a light/dtc when there is a misfire and you keep motoring on unitl CMP/CKP come back into range or you feel a dead miss that the PCM didn't detect and mitigate.
This all allows a misfire to go undetected straining the weaker pistons, until the skirt cracks, then it splits, then it chunks out, then it goes gonzo.
Thats just my theory.... nothing other than pure talking out of my arse. I came to that plausable explination after talking with a handful of customers and hearing similar stories no light, good verified service history, etc. Coupled with a handfull of my rigs, and engine work on the side- and talking to Bob @ ICS who agrees, and he seems to seen alot of them too go out that way.
Of all the cracked skirt 4.0/2.5s I have brought back to life with replacing cracked skirts with improved pistons and honing or boring if need be; I never had one come back and to the few I keep in touch with have gone 50 60 80K since my engine work without issue.
Im the guy who makes new gauges, check out our gallery at Teamadw.com
The 4.0 in my XJ blew without any warning at 100k miles, never did get a satisfactory explanation but I presume it was just poor maintenance in the 70k miles before I owned it. So far the one in my LJ has been trouble-free for 45k miles (been getting an intermittent O2 sensor code for about a year, but that's hardly the block's fault).
All indestructible work horses IMO they should have never done away with them !
I agree. We had a 93 ford f150 with 4.9 with a 5speed connected to it and it was a torquer. I have the 4.0 in my yj and xj. My xj I put through hell, Ive overheated it on more than 1occasion, ran it low on oil once before, and my wheeling mostly consist of mudriding. Since my xj is stock with some walmart ats the skinny petal was my bestfriend and I stayed mashing on it. I had a old dodge dart with a slant 6 that was a dog, but that engine was tough too.
"Its a Jeeps World, other 4x4s just get stuck in it."
Jeep had a rough spot around 00-01 but since then they have been trouble free, and most of that was head, and manifold issues. I have an 03 with 85K on still runs great, my dad has 98 4.0L with over a 175K on it still running strong. These are both in TJs. The 05-06 TJs have OPDA issues.
2003 Jeep Wrangler Rubicon
4.0L, 42RLE, Dual Tops, Full Doors, JKS Front Disconnects, Cragar Soft 8 Black Wheels, 33x12.5x15 Goodyear Duratracs, .75" Front Coil Spacers, Bushwacker 6" Flat Fender Flares, Skid Row Steering Box Skid, LubeLockers, Rubicon Locker Mod, OBA, Cobra 19 Ultra III CB, 3' Firestik, Rough Country 2.2 Steering Stabilizer, RC 1.25" BL, RC 1" MML, RC Grab Handles, Fog Lamp Bent Pin Mod, 4" Apline S Series Speakers, Kenwood Excelon 6.5" Speakers, 6.5" JL Audio 6W3V3 Subwoofer (in center console) w/MTX Thunder 202 amp, IPF H4 Headlight Housing, Sliverstar H4 bulbs.
Straight 6's are hard to beat...the old Dodge slant 6 was damn near indestructable..
Damn near? When I was in high school, a buddy of mine drove a 68 Barracuda with a 225 slant 6. He had a built 360 sitting in the garage just waiting to get dropped in but his dad put the nix on that until the slant 6 died. Us being the high school kids that we were decided to accelerate that. He brought the car into the auto-parts store that I worked at and we drained the oil out. His plan was to drive the car until the engine exploded. Two weeks later it was still running when his Dad found out about our little plan.
Originally Posted by Hendrix
No one really knows the reason for LCOG Jeeps.
Its so short ****s like me and you can still get in.
Originally Posted by 2ACR
My issue was I couldn't get the balls centered. I had to use some extra force to get everything lined up right. It didn't take me long.