PanAm330 From United States of America, joined Mar 2004, 2760 posts, RR: 8 Posted (8 years 11 months 1 week 6 days 12 hours ago) and read 8409 times:
My friend has a 2003 Dodge Neon that lately has been shuddering, and one time even ceased. I've noticed the shudders only at idle (after it has just been started up, at a stop light, etc), however it's "bucked" a few times when going 30 or 40mph. After a talking with my father, he suggested that it could be the spark plugs, or the timing belt. I figured that I might as well ask here before I go and get charged by a mechanic to tell me something I might have been able to find out on my own. Does anyone know what could possibly be causing this?
Thanks to all in advance! All input is appreciated.
LTU932 From Germany, joined Jan 2006, 14231 posts, RR: 46
Reply 7, posted (8 years 11 months 1 week 6 days 9 hours ago) and read 8353 times:
Check if all spark plugs are connected to the electric system or that the cable that connects to one of the spark plugs isn't damaged. One time it happened to us that our engine stalled and one of the connectors went lose, meaning that once we restarted the engine, it was shuddering and stuttering all the time. We didn't find out about this until we went to a shop nearby. We drove for some 10 or 15 miles with only two of three cylinders, and even had to go uphill several times. It was a real strain, but the engine held through and once we found out the problem, it was a less than 5 minute fix for us and we were back in business.
If the car has a carburator, I'd check if there isn't something that is interrupting the airflow, like a rupture in the rubber "pipe" (don't know how to say it in English) that goes from the air filter to the carburator. If there is such a rupture, the car can still drive with no problem, but there will be lots of shudders when the engine is idle.
TZ757300 From United States of America, joined Aug 2005, 2911 posts, RR: 5
Reply 8, posted (8 years 11 months 1 week 6 days 8 hours ago) and read 8325 times:
Since it sounds like its speed related since it does it at idle and at around 30-40mph, it might well be the distributor. It may not be catching with the cam or even the cam is locking up somewhere and causing the bucking or stalling. Or perhaps its the transmission. Its probably an auto knowing its a neon in the US, but a problem I had once that something would lock up in the transmission sometimes and would make the engine shudder a little bit or if it locked up long enough, stall the engine.
Really, it could be a wide array of things. I would just go to the dealer and get it checked out. Just for reference, what kind of engine do you have?
Most vehicle's electronic brains store self-diagnostic codes when an engine/fuel management device is giving bad signals. Once this code is "de-coded", a particular part replacement can be determined. Codes are usually read in the shop by a hand held tester that plugs into the car's diagnostic connector. On some cars, two pins on that same plug can be shorted to make the "check engine" light on the dash blink to give the code. Obviously, you would need to check the [i]factory[i/] technical manuals for your make and model for any shortcuts like that, but codes can tell a lot.
My money says its your oxygen sensor. A bad sensor usually makes for rich fuel mixtures, which makes for rough idling. Good luck!
My car is actually doing the same thing, that is, "bucking" when driving along, not shuddering at idle. The engine "bucks" mostly when driving up an incline with revs that are a little too low for the speed. Given my car has almost 180,000km (112,500 miles) on the clock, I suspect that it is the clutch slipping momentarily that is causing the problem.
JetMech split the back of his pants. He can feel the wind in his hair.