I've been trying to get to the bottom of the jerking/performance problem that my car has been having.
Sometimes, when I turn my car on from a cold start, the revs will keep dipping.
If I put my foot down on the pedal a bit, the revs will drop all the way down with the car making a clunking noise as they reach the bottom, then it will shoot up and begin dropping again.
After about 10 minutes of driving, the problem will suddenly disappear, no gradual changes, it will just suddenly drive fine.
A clip of the uneasy revs can be found below:
Restarting the car doesn't help, I just have to ride the jerking out until it stops.
When filming that video, I noticed some smoke coming out of the right hand side of the engine cover near the right side of the engine so I stopped straight away and turned the engine off soon after.
Also when travelling at speed (e.g 65mph), when putting my foot down relatively hard, the car will begin to accelerate and then start juddering backwards and forwards whilst accelerating. Easing off the pedal remedies this problem.
I've tried disconnecting the MAP sensor and the car drives much better, also feels more performant when accelerating. Soon after disconnecting the MAP sensor the following error codes come on:
P0238 - Turbocharger / Supercharger Boost Sensor A Circuit High
P0488 - Exhaust Gas Recirculation Throttle Control Circuit A Range / Performance
P2141 - Exhaust Gas Recirculation Throttle Control Circuit A Low
After plugging the MAP sensor back in and clearing the codes and a few lucky miles later without the car jerking, error codes P0488 and P2141 both came back on (Exhaust Gas Recirculation).
- Car drives better with the MAP sensor disconnected but I get a few error codes after a few miles
- With MAP sensor connected, the car sometimes jerks/judders
- Could be the MAP sensor, or maybe MAF sensor? Also maybe the EGR valve due to Exhaust Gas Recirculation error codes?
Also I don't know whether I should be concerned about the fact that the car drives better with the MAP sensor disconnected, I've heard that it's supposed to degrade performance when disconnected, meaning that the performance of my car with it connected could be lacking but I don't know (a friend of mine said getting up to 60mph in my car was quite slow even with my foot down, getting up to 30mph is fine though).
Any help would be much appreciated on what steps I could take next! Thanks!