Hey guys, well I have something a little bit strange going on with my 98 Stratus ES w/ 6cyl auto trans. Typically, this is the deal, I will start my car after it has been parked for a bit (a couple hours or more), and it will run fine.

When I drive even just a couple of miles then put it into park, or even just try to start it back up if it has not been parked for more than a couple hours, these are the things I see while in park:

1. The idle won't be constant, it has jumped from its typical idle of about 600 rpm, up to 2000 rpm once, most of the time it will only jump up to about 1000. It typically will only jump for a few seconds, then drop, then jump for a second, then drop, etc.

2. At the same time, the speedometer will be jumping randomly as well, anywhere from 0-70mph, while sitting in park (all other guages are normal).

3. I think I have possibly heard a slight thud thud from the exhaust now and then, kind of like a backfire while it is doing this.

4. If during this time that it is jumping all over the place I go to put it in reverse, it will stay in neutral. If I switch it to drive, it will kind of jump slightly rough into first, and from there, it will allow me to put it into reverse, which it does jump a little rough into reverse from there as well.

5. All the while that it is doing these things, I don't get any lights coming on - no check engine, etc. It is not getting stuck in second either. When in drive, it runs and shifts like a million bucks. Just the issues in park.

Again, I don't know if it is just coincidence or not, but I have yet to see these things come up from a cold start. Any help on this one? I have my fingers crossed, but I am definitely thinking it may not be a good thing. Thanks so much guys!

 

sounds like it could be idle or speed sensors. can't think of the exact ones off-hand. When was the last time you changed your plugs/wires? And how many miles do you have on your strat?

 

Hey there, thanks for the reply, I am sitting at just over 140,000 miles, and I have not changed the wires or plugs, in well, a very long time if at all. I am trying to remember, I bought the car at 85K and i think he said they were just changed, and I dont think that I have changed out anything personally as far as plugs/wires go. If something was wrong with the plugs/wires/dist caps, wouldn't I get the check engine light? I am under the impression that I would, and therefore, have not really given the ignition of each cylinder much consideration.

As far as the sensors, it seems like that might be on the right track. If I don't have the CEL lit up, is there anyway to check for codes that might confirm that? Thanks again for the help!

 

there are some codes that are stored that don't throw the CEL. I for one, have never seen my CEL come on. Mainly because the bulb is burned out I would take it somewhere to have the codes read. around here Autozone does free scanning. Some sensors may be stuck reading a NORMAL reading, when in fact it's not.

It's a solid car if taken care of. I bought mine at 140,000 last year, and am now a lil over 170,000.

 

Bulb was good . Anyway, just took the chance based on the logic of what the car was doing.

Speedometer would jump, car would not go into reverse, engine would idle weird, I get concerned. Basic order of events.

I replaced the input and output speed sensors on the trans, don't know which one was the fix, but it's good as gold now. The speedometer would be all over while in idle due to the bad sensor (why only in idle opposed to drive, no idea) the car obviously wont let you throw it in reverse when going at any high rate of speed-as the speedometer (and car) was thinking I was going. Engine would idle weird due to the air/fuel mix that the cpu was throwing based on going "x" miles per hour, when in reality, it was 0, with no load-giving the unstable idle.

Hope this helps anyone in the future, thanks for the input! And yes, these are pretty solid cars, bought by ES three years ago at 85,000, now sitting a little over 140,000. For $2700, I can't complain, just wish the rust that we all fall victim to here in michigan didnt happen. Also, the front ends are kinda weak on these, but then again, I do live on a dirt road, and again, in michigan, where potholes eat cars for breakfast. Take care!

 

Output Speed sensor= NO speedometer output and tranny in Limp mode

Input Speed Sensor= unstable shifting and a few other things (Jumpy speedo)

 

Unfortunately, somehow, the problem has resurfaced. I suspected that I had bad luck, and got a short-life sensor. Replaced both again, although it seems to be the input that fixed it last time from feedback on here. That was two days ago, and just a couple of hours ago, it did the same thing again. It didn't do it at all over the past 3 months or so. Still no CEL.

Where to go next, search for short/ground, control module, trans fluid, cluster? Any input is appreciated, thanks so much!

 

try starting on the cheap, spark plugs, wires, coil, air filter, etc...

I had the same problem and i replaced the o2 sensors and it seemed to solve the problem, also check for any exhaust leaks

 

Hope someone whould post a fix, Stratus ES limp mode, speedo bouncing, input out sensor's changed, Dealer reported pins were bent, but after 20mins same problem, cars back at the dealer, quoting $650.00 and still may not fix problem.
I see some posts with the same problem but no answer if the fault has been fixed.

Any Help...