2002 RAM 3500 van 5.9

[melectrica]

This is my work vehicle. I have been the sole driver since it had 17,000 miles, and it now has 160,000. I have had no major problems with it until the start of the cold season. In the first really cold morning I noticed at start-up it was running rough at start-up idle and while driving & it subsided after it had warmed up to temp. Well it has progressed and now has a mad vibration (kind of like it has lost a cylinder) at idle and while driving and it does not go away whatsoever. Early on, my cel was on and I already knew what the two codes were (bad gas cap seal and the bank 1 sensor 1 O/2 sensor) I fixed the gas cap seal right away & the code cleared and then I replaced the O/2 sensor a couple weeks later. That code cleared as well. During that time I also replaced the plugs, wires, cap & rotor w/ no results to remedy my problem. The cel is not throwing me a bone here as to where to go & fix the vibration. My gas milage is at about 7 or 8 mpg so thank GOD gas is at an all time low since recent years! lol (I remember the .99 cent gas wars in the '80's... haha) anyway, I SO need to get this thing up & running again FAST! I have a really good friend who is a contractor now (I'm an electrical contractor) and he was (WAS) an ASE Cert. Mechanic in the early '90's and he's been a great help, but it seems he is at a loss as of now. He has mentioned a compression check on the cylinders, but doesn't think it's the problem. I think it's a vacuum line somewhere, but if it was, wouldn't the cel light up for running too rich or lean??? H!E!L!P! (please)... /
Btw, I am a complete noob as far as being a mechanic goes, but lately I have learned a lot with the help of my good friend who is helping me out! I actually have had all my front end parts in the back of my van waiting to be installed by him (with my help of course) but I keep having these other issues pop up that take priority! (We've recently replaced the fan clutch, water pump and radiator at the end of this last Summer) and the A/C has been giving me lip TOO, but I have everything I need for that when that time comes, I just need to figure out why it's running like sheee... it!!! (can I say that...)? lol

 

[Merc225hp]

Do as your buddie suggests comp test, start with jug #8. CKPS is a big suspect part here, it will not flip a cel code but will make jugs drop. Plenum gasket does he know about those on these motors? there is a right up here on RF about it. There is a TSB for spark-plug wire routing, should have a look at that as well. What type of spark-plugs where installed? should be plain old copper plugs nothing fancy ass like IR or platinum.

 

[melectrica]

Thanks for your quick response! Yes, I was told to NEVER replace anything with fancy crap & to always go with the standard Mopar (for Dodge of course) and standard GM parts (for my Chevy's) when doing tune-ups & what not. He does know of the plenum gasket(s) though, and he's asking what the problem is with them, but I will take a look at the write-up on here and relay it back to him or send him a link...

 

[Merc225hp]

I should have posted the link sorry about that.

http://www.ramforum.com/f61/plenum_gasket_what_where_what_should_i_do_about_*info*-37635/

Gasket fails causing a vac leak, miss, oil consumption, spark knock, fouled plugs, plugged cats, cracked heads.

At this time comp test would be my first step before anymore cash is spent, make sure you still have a good motor to work with. Plugged cat could be that as well.

I am not going to get into tests and how to do them as you have a tech helping you. If you do need me to just ask.

Also the 2001 fsm can be downloaded here on RF in the Diy area, its can be a big help.

TSB 18-48-98 is for spark-plug wire routing and should be followed to the T.

 

[melectrica]

Will do! One of my clients (Sun City Fire Dept.) referred me to the mechanic that they take their entire fleet to, so I decided to stop by there & pick his brain a little! Haha
So he started it up, checked out what it was doing, looked at the motor under the hood and from underneath the carriage. He (Jim is the lead mechanic's name) said that it's a VERY unique vibration & doesn't think it's fuel related. He's leaning more towards the harmonic balancer even though just looking at it seems okay, he'd just have to look further into it to really know. And since he said he wouldn't charge for a diagnosis, I think I should take him up on his offer! Although he DID say if he had to start digging into & removing motor parts, THEN he would have to charge me...