318 v8 - "bucking" is the best word I can think of .... does it at idle and while driving...pretty much constantly....not as noticeable when accelerating.....has either 135k or 235k miles on the engine. Would just like some troubleshooting procedures to run against it.....the codes checked okay. Maybe a loose or worn timing chain?? Any way to check that (physically)?? Since I finally got this thing to run (at all), I'd now like to get it to run WELL. Thx, Mike

 

I had the same problem with my truck and I had moisture underneath the distributor cap and on top of the rotor button. And check around the throttle body make sure that vaccum lines are hooked up and no leaks.

As far as checking the timing chain, i think you have to take off the timing cover n such.

 

replaced rotor cap and button, even though they looked okay (cap had "Made In The USA" stamped on it, so, sadly enough, I figured it had to be OLD). Vacuum lines will be next. Thanks for the input!!!

 

There is a procedure in the Haynes manual for checking the slack in the timing chain. Basically, you turn the crankshaft clockwise to ensure all the slack is out of the chain - make sure the timing mark on the pulley is more or less lined up w/ the most advanced timing mark. Next, with the distributor cap off, rotate the crankshaft counterclockwise, noting how many degrees the pulley moves before the distributor moves - this represents the slack in the timing chain. According to the manual, anything more than 10 degrees is BAD - mine is showing anywhere between 14 and 20 degrees of slack. Additionally, believe it or not (at least for me), there is no tensioner on this timing chain (318 / 5.2L engine), so not very hard to believe this amount of slack in an engine w/ a lot of miles on it.

I plan to replace the chain and gears AND add a tensioner....I'll let y'all know how things work out. Any and all comments welcome!!!

Here are some links to the forum that suggested adding the tensioner:

http://www.forabodiesonly.com/mopar/.../t-136340.html

and to the tensioner itself (from Mopar):

http://chucker54.stores.yahoo.net/timchainten.html

- Mike

 

mine had 127,000 when i changed my timing chain and gears out,it had lots of slack but still ran good. i knew it needed to be changed because when i reved it up in park when the engine would drop back to idle it would almost shut off or stumble. this was caused by all the slack backlash. i put the MOPAR PERFORMANCE double row roller chain and gears in mine. roller chain has less chance of streching,also has no chain tensioner.
went in perfect didnt even have to reset the timing.
cant remember the price but think about $75 at the dodge dealer.
been working on 318's for 25yrs. i personally would use a good quality roller chain and gears. just my thought?? good luck

 

Parts are like paint...when 90% of the job is LABOR, it's just plain dumb to go cheap on the parts...I'll let y'all know how I make out when I'm finished...might be a month or so.....thx for the reply!!

 

No doubt the rookie mistake of the century. I assumed when I bought the plugs that they were pre-gapped. Properly gapped the plugs (.035", btw) and the thing is running like a champ. I hesitate to confess such a bone head play, but if it helps anyone else out, I guess its worth a little embarassment. I'll probably still get around to the timing chain, but at least for now its driveable!!!! thx for all the input!!!

 

I doubt there is anyone on here, that is honest, that has not made a forehead slapping mistake. The thing everyone reading this thread should remember is that if you want help you need to tell us everything you have done to the truck prior to the problem surfacing. This is the first you mentioned that you replaced the plugs.

 

Again, many thanks to everyone - esp. you, SEAL, that have helped me navigate through the many issues w/ this vehicle....and I'm sure there will be more in the future.....