If you can see the donor vehicle would be better. Would look for a nice looking "wrecked" vehicle, have better chances of good drivetrain. I would walk away from vehicles with no apparent sign of accident, especially if it looks not very well cared for.
I sold my 06 DGC with 317,000 + miles, original engine and transmission, still running very strong and quiet, so those things are made to last, if you take care of them
2012 Town & Country
2006 Dodge Grand Caravan. 317,000 + Miles. -SOLD-
Had some free time this week and decided to dig into the engine out of curiosity about what went wrong. Started off by seeing that the front head had a broken head bolt. Never a good sign. Got the top half of the intake off and saw a small amount of aluminum debris in one of the runners, also not a good sign. Nothing unusual when I got the valve cover off. Finally got the head off and now I have a mystery that I'm hoping you guys might be able to help explain. First, I saw a head gasket that had been clearly leaking around the broken head bolt for a long time. No surprise there. Checked radiator and water is about 4 inches below the top of the radiator core, which is enough to stop flow in my experience. Then, I saw broken pieces of high strength steel inside of each of the cylinders, but no clear sign of where it came from. In two of the cylinders the pieces got hammered by the piston until they stuck into the combustion chambers. On the third they just kept bouncing around and chewed up the combustion chamber and top of the piston until it eventually damaged a valve seat and caused compression loss which set a misfire code. The steel pieces almost look like chewed up gear teeth, but hard to say for sure. I can't explain where they came from, but I suspect they came across the intake manifold from the other head. I'd like to pull it but it looks like it can't be pulled with the engine still mounted.
So, it looks like: failed (or improperly installed) head bolt, failed head gasket, water loss, over heating, internal failure. Even if a valve failed, they break through the piston and into the oil pan and I see no sign of that, such as metal flakes in the oil. Pulled other valve cover and everything looks normal there too. How tough is it to drop the engine? I need to get it out anyway to get another one in, anyway. Has anybody seen a failure like this before?
I pulled the transmission, not the engine, but I imagine that most of the work is the same, except that you lift the engine up rather than drop the tranny down. With heads out of the way, it should be pretty easy.
Basically you need to three mounts (front, rear and driver's side), remove the starter, and the engine to tranny brace, pull TC cover, remove TC bolts, and then unhook all hoses, wiring, etc.Remove bellhohsing bolts with tranny supported and lift.
Obviously check FSM for proper directions, but should be straightforward
... I suspect they came across the intake manifold from the other head. I'd like to pull it but it looks like it can't be pulled with the engine still mounted. ...
You need to remove the wiper tray (2 parts). It is fairly easy. After ~3 times, I can get it off in <10 min. You need to get it off to do a decent job replacing the rear valve cover gasket or replace the power steering pump. With the wiper tray off, you have a straight vertical clearance down to the engine. To remove the engine, I think you will need to remove the hood. If so, drill small holes to slip in nails for later alignment or you may go crazy trying to get the hood aligned again. My 1980's M-B cars have a release that lets you put the hood straight up for engine work (smart idea).
It does sound like a mystery. Once you remove the timing cover, you can tell if the timing chain could have slipped a tooth. Your V-6 engine is very similar to old Chrysler small-block V-8's (push-rods, shaft rockers, ...). The only old V-8's known to skip a timing chain tooth were those w/ nylon camshaft gears (for quieter, mid 1960's). I doubt you could get enough chain slop to skip a tooth. Even if you did, I doubt the engine would run with enough skip for the valves to hit the pistons. Indeed, this may not even be an interference engine. My 2.4L 16-valve apparently isn't since its rubber timing belt has failed twice w/ no damage. More suspect is that some roller lifters somehow came apart to jam the valves far enough down to strike a piston. I don't know how that could break a valve into pieces since aluminum piston vs hardened steel = aluminum loses. You must pull the heads to get at the lifters.
Where do you live? There has long been a new 3.8L engine advertised on the Sacramento Craigslist for ~$1000. A great deal if you need one. But, first read the Engine Builder's web article to note the differences. Some blocks for RWD Jeeps have different mounting pads. Speaking of that, many Jeep owners rant about the "dang minivan engine" (around 2008+) and would love to swap it for the well-loved 4.0L straight-six. So, there might be some sitting on the floor of a garage they would love to unload cheap. Check Jeep sites, but insure your mounts and accessories will bolt up.
When you do install another engine, smart to install a new flex-plate (and rear seal while off). My 2002 flex-plate had cracked all the way around under the ring washer and rotated ~30 deg. Amazing the engine still ran off the "toner ring" slots (spark timing). This is a common problem w/ the 3.8L engine (more torque). I didn't even have to open the pizza box when I walked into the Chrysler dealer. The mechanics hanging out at the parts counter, said "bet you need a new flex-plate". But, fairly cheap (~$70).
Last edited by BillGrissom; 04-20-2017 at 11:53 PM.