Hello all, as you can tell I'm new here, as well as pretty new to automotive repair. So bear with me if I sound noobish or ignorant about what can be done, or what procedures are available to me. =) Please bear with me as I relate the tale that spurned this post.

I purchased an excellent condition '95 Avenger ES V6 in November '05, ran smooth, engine purred, things looked good. When I brought it home, I did what I imagine most people do, replace filters, give it a lube job, replace the spark plugs, and clean the intertior. Basically the essential preventative maintenance that you don't really know was done or not by the previous owners. Come around March this year, I noticed a slight knock, not really all that audible, and having put 3,000 miles on decided it was probably time to do an oil change, seeing if this would also help clear up the knocking. I also found that in the owners manual they highly suggest platinum tip plugs, I had installed autolite coppers when I did the initial change in November, so I purchased some autolite platinum tips. Now comes the part where it gets harry. Upon advice from a friend, who said the knocking may be occuring due to gunk and build up in my engine, that I should try some engine flush. SO...I proceeded with putting this engine flush in, ran it for 5 minutes as per the instructions, drained the oil, replaced the filter and then filled the engine back up with new oil. I started the car up and it ran fine, although the knock was still there (which I later read is no real big deal if it's a slight knock). I then proceeded with the spark plug install, went smoothly...though at one time I thought one of the lock washers for the plenum fell into the intake...(still not sure, but will explain more). After the plug installation I started the car up to see what the fruits of my work have sowed, only to find the harshest sound ever, severe belt squels, and engine clacking, followed by rough idle and stalling. I tried starting it again but it wouldn't turn, I was mortified, I then checked the plugs to find them severely wet fouled with blackness (oil), I cleaned all the plugs off, and reinstalled (which I have now learned you aren't supposed to do). The engine started but refused to maintain any idle and would die after a few cranks out of the engine, giving a little gas would help prolong it's runnning by only a little. After rechecking the plugs once again, they were suprisingly clean, and did not have the fouling as the first start had, which further confused me. After much tinkering (replacing the oil AGAIN, buying different brand oil filter, new platinum plugs) the car now starts, BUT a loud clacking comes from the engine, sounds like an old beat up truck you hear in the movies. I took the car around the block once (about 1/8 mile) and it started dying on returning to my driveway. Several thoughts had cropped up, I thought maybe the plenum lock washer DID land into the intake, causing maybe one of the cylinders to fire incorrectly, thus producing this clacking, as later searches did not yield the washer from the driveway floor. Also perhaps the engine flush has washed away beneficial grit/rust/build-up in the engine and had allowed some parts to free themselves a bit and cause this malfunction. Of all this I do not know what one would be the culprit.

So, my mothers fiancee was called in, he's a very mechanically inclined person, and has worked on his share of cars in his days. He hypothesises if indeed a washer did land in one of the intakes, it might have caused a valve to be propped open, and consequently one of the rods to become damaged. He thinks, if this isn't the case, maybe one or more of my rod bearings are bad.

So I'm asking if anyone from my story, would be able to deduce what could be wrong, taking in account the small washer, as well as the possibility of the washer not have been dropped into the intake as well.

Because of the possiblity of the washer being in the engine...or rather being chewed up and ruining the cylinder walls (which I will be checking the oil pan for metal shavings/chunks as I have been suggested by an automotive faq), I might be faced with doing an engine overhaul. Rather than replacing singular parts that may cost me hundreds, or maybe a couple thousand (neither of which I really have), I've been told an engine replacement might be a cheaper way to go. There are several pull-it yourself yards around this area, as well as spare part resources that I may find used engines at, and was wondering what model cars or engines are compatible with the least amount of extra install work that an identical engine would require. As I don't have a machine shop, or real welding experience, I do not think taking a motor from a comparitive model that require a new mount etc, would be viable for me, as well as the possibility of taking the car into a pro, as my finances won't allow it.


So in conclusion from all the mess I describe above, I basically have two questions. What do you think the problem with my car is? and What engine makes/models would be compatible with my car in case an identical engine cannot be found? or possibly if an engine replacement is even necessary.

Thank you in advance to anyone who reads this and can provide some help, as well as anyone else who endured reading that and couldn't come up with anything =)

 

First off, welcome to DF Ressie
Wow, that does sound bad. When I did work on my 2.5, I was afraid of things falling in too and I never rushed it or shrugged it off if I misplaced something (and that happened a lot, lol). I've dropped a few nuts/bolts/washers back there and they ARE hard to spot, they usually fell on the steering bracket or the tranny (luckily for me). Yours does sound bad, clanking is never good. A motor flush was a good idea and shouldn't produce harsh idle unless the problem was already there and just hidden by gunk, like you said. Most folks that do that get a smoother running motor. I hate to jump to conclusions but I think that the washer fell in, saying that it's just all a coincidence isn't far fetched either, but.......since it was running fine before and then clanking after......
You can remove and reinstall plugs, why that would hurt anyone's car, I don't know, I for one remove mine to check for detonation or richness every so often, or to just check the motors health...doesn't hurt unless the plugs are already bad. Make sure the gapping is correct (not that it will help the clanking). I would also recommend the bosch platinums (that was stock).
A motor replacement is definitely cheaper and more bang for the buck (if the motor is in good condition). There's not a lot that can just drop into our engine bays though...another 2.5 V6 is about it[]. Unless you want to do modifications here and there...probably not. Dodge Avenger 2.5 V6 years 1995-2000 will fit without a hitch. 2.0 motors were also available but you would have to change the engine wire harness and electrical components.
Just know one thing....the 6g73 block and head are REALLY TOUGH. It takes quite a bit to ruin that motor because the cylinder walls are pretty thick! I say get a quote on rebuilding the motor and if that seems high to you put another 2.5 back in, or find a 6g72 3.0 Liter in good condition and do the 2.5/3.0 hybrid. I'll post more on that if you're interested.

Sorry to hear about your car, but now that it's happened let's work on getting her back on the road