Chrysler Repair: 1998 Neon has started running roughly., water condensation, dodge neon

Question
QUESTION: Hello,
I recently purchased a 1998 Dodge Neon Highliner Coupe.

Within the last few days, it has begun stuttering during acceleration from 0-20mph. After a particularly jerky bout earlier today, the "Service Engine Soon" light came on. I have also noticed a water leak underneath the car (near the right side of the engine in the middle). At first I thought it might just be dehumidifying, but it seems to leak whether or not the car has been recently running, though the leak is very slow.

In addition, it shifts a little roughly and has occasional tremors around 65-70mph. (The transmission fluid is fine.)

The following work has been done to it within the last two months: The rear main seal on the crankshaft has been replaced, the timing belt has been replaced, and the head gasket has been replaced.

Can you offer any suggestions?

Thanks,
Jack

ANSWER: Hi Jack,
I would get a fault code readout of the engine controller to see if the engine controller has noticed a problem in the operation. You can often get this for free at an Autozone parts store if there is one near you, or for around $40 at an independent garage. On the leak, I would suggest that you park it at one spot, then jack it up without moving it and support on a jack stand, then get underneath far enough to locate the source of the water leak or at least which area of the engine it is coming from. If you have been using the AC it could be plain water if that were the case, as you suggested. Water condensation will drain slowly from a hose at the midline of the firewall. If it is green or orange then that is a cooling system leak.
Then based on those results we can evaluate whether any of the recent repairs may have been related to the problems and if so you could return to the shop and ask them to repair the problem related to their earlier work. Alternatively, if not then decide what to do to fix a new problem. When you have the code readout, get the fault code number(s), ask the name, ask what repair is recommended, and how much it would cost.
Write back and let me know and we'll go from there. Please tell me the engine size that you have in the car.
Roland

---------- FOLLOW-UP ----------

QUESTION: Thanks Roland,
I took it to Autozone earlier, though the machine gave a "LINK ERROR" code; it couldn't make a connection. We tried several times, but with no results.

As for the leak, I believe it is probably just condensation from the air conditioner. Only pure water is leaking, and after letting the car sit overnight without running, I checked this morning and it appeared to be dry underneath. I'll keep a close eye on it.

The engine is a Chrysler SOHC 2.0 liter. There's a pretty excellent website detailing the history of this model engine here: http://www.allpar.com/mopar/2.html

Sorry for the lack of information. Seems like something invase might be necessary for a precise diagnosis. I hope some of this information might ring a bell, though.

Thanks,
Jack

ANSWER: Hi Jack,
About the only possibilities for 'Link Error' would be either the ignition switch was not turned on properly when the test was tried, or there is a short or open on one of the wires from the readout socket to the pcm, or the pcm is malfunctioning. or the readout instrument's cable is bad. If you believe that the ignition switch was "on" at the time of the readout was attempted,and if you have an ohmmeter, I can tell you which wires to check out.
Roland

---------- FOLLOW-UP ----------

QUESTION: Hi Roland,
I just picked up an ohmmeter and am ready to search for the bad wire if you can give any advice as to where it might be. Thanks for the help.

Also, I have noticed that it doesn't sputter as badly if I accelerate slowly. The slower I accelerate, the smoother it goes. If I have to make a right turn onto a speedy highway, for instance, there's a bigger chance of it puttering up from 0-20mph than if I am just turning onto an exit ramp to get on the interstate.

Jack

Answer
Hi Jack,
The data link connector plug under the dash has 7 wires, as follows:
pin 3 violet/brown to the air bag control module pin 19
   4 black/tan  ground wire (see below)to the power steering pressure switch and on from there to pin 45 at the pcm on a white wire
   5 black/tan (also tied to pin 4 wire at further disconnect) to ground at top left of radiator closure panel
   6 light green to pin 75 of the pcm
   7 pink to pin 65 of the pcm
   11 white/black to pin 16 of air bag module.
   16 red/white from fuse 21 under the hood should have 12V at all times
Pins 6 and 7 are the key ones for the link connection of data, but also pin 16 would be needed for powering the reader. I would check to be sure of the connections of the first 6 wires, and that when disconnected at the far ends, that the wires are not found to be ground (except of course for 4 and 5 which are ground wires. 3 and 11 are air bag wires and probably wouldn't be related to no link problem. So it really is 16 should have 12V, and 6 and 7 have to be connected to the pcm and not accidentally grounded.
If those check out then I would try a readout somewhere else.
Here is another suggestion: Try checking out your egr valve to make sure that its valve stem is moving freely back and forth and that the spring action is closing it. There is a slot in the valve stem into which the tip of a screwdriver can be inserted to move and test its action. If it is hanging up, spray some WD-40 on the stem where it enters the valve body. That failure to close could mess up the mixture and make for bad acceleration behavior. The stem is between the round vacuum operated top and the body, inside a flanged area.
Roland