So here we go again, after being truckless for a few years I bought a 98 with almost 200k and made a point to find one with a rebuilt transmission. Since the 99 I had crapped out on me. It also came with a trailer brake controller so it was clearly used for towing.

I test drove it and it seemed to perform well so I bought it. But after towing a few things and driving it around more I noticed the subtle issues.

Quick history: Shifting was hunting for gears, checked fluid found it low by one quart and amazingly that is all it took to make it better. Found that while on the highway it does not like to drop down to the correct rpm all the time. It will be up a couple hundred rpm and it feels a little bit rough. To get it where it needs to be I need to slow down to 60 and feather the pedal just right then it will stay there if I speed up gradually without shifting. It will also feel this way when it is not warmed up at low speeds but at such low speeds rpm info is pretty much invalid. It is also getting pretty bad mpg like 10-13 when it should be getting 15 the way I drive and that is what my last 318 got.

Also it makes a good clunk If I jam on the brakes real good. Put all new shocks on but it still does it just not as bad. Doing a full brake job as of this writing.

What I have done so far: Took it to get the codes read and got cylinder 1,5 misfire. 301,305 and torque converter clutch system mechanical system performance failure 740. Found all trans pan bolts not tight, they all took a good 1/2 turn and two were stripped so I am working on a fix for that.

Other stuff may or may not be useful; codes did not show up until I started towing jet skis/ 19 boat/ 23' boat into a rough, gravel, & sand launch. Found rear end to have lash and not smooth when I jacked it up and spin the wheels.

ok thanks for reading and I think I got it all out there!


Edit: just remembered I checked the TV cable it was good. Also it does not feel like it is misfiring and feels like it has all the power that it should. Quick plenum check and its not pulling vacuum at the oil fill or blowing.

 

If the PCV system is working properly, there should be a slight vacuum at the oil fill. Lay a piece of paper near it, and see what happens. (at least partially over the hole)

The 740 code makes me nervous. It isn't whining about the solenoid, it's whining about something mechanical.... which I would guess points to the torque converter...... Think I would wanna gather more info before just replacing it though.

What do the plugs/wires/cap/rotor look like? A corroded cap would give you a miss....

 

I changed the timing chain when I fixed the plenum on our truck. It runs really smooth now. I suspect your chain is loose. I wrecked the gasket between the oil pan and timing cover, so I had to remove the oil pan.

New spark plugs (NGK,Autolite) , cap, rotor, and wires if needed. New O2 sensors (NTK,Standard Motor, Mopar). Clean or replace IAC, check for vacuum leaks, new PCV valve and air and fuel filters.