I own a 2011 Renault Modus Automatic and for the last six months the car has been great, no issues.
This week however, a problem has started. The car has begun to judder at random points and then when braking to a stop for traffic lights/junctions the power will sometimes cut out meaning I have to restart the whole car to whirr it back into life (this always works but I’m loathe to begin risking this over middle or long distances). This problem started on Monday and I initially put it down to the chillier weather we have been experiencing recently but today - when it is far milder than at any point this week - the problem persists. This is probably an easy problem to diagnose but i’m not very car-lingual.
If anyone thinks they know what might be the problem then I’d appreciate any feedback.
It could be that the torque converter clutch is not releasing. That could cause the judder and would cause it to stall when coming to a stop. Have you checked the transmission fluid level? Is the Check Engine light on? I’ve never worked on a 2011 Renault so I have no idea what the light looks like. It may look like a wrench.
There’s a lot of possible reasons why that symptom might develop suddenly in a car that was previously running fine. Best method toward a solution is to try to narrow down what system is causing the problem. The three most likely sources: fuel/air ratio problem , spark system problem (presuming gasoline engine) , transmission problem.
For fuel/air ratio, use a scan tool to monitor the fuel trim parameter. Even the less-expensive diy’er scan tools can often perform that function, part of their real-time mode.
For spark, a shop w/a pro-level scan tool is usually the best first step. However if it is possible to observe the spark at the tip of a spark plug during cranking, it should be robust looking and bluish-white. Orange-ish usually indicates a problem. Nothing in the engine compartment should looks wet or damp. Often the cause of a spark system problem. So look for signs of rain water leaking into the engine compartment area.
For the transmission, listen for weird noises, try to observe how the symptoms changes in various driving modes, different speeds, different gears, coasting vs in gear, forward vs reverse, an just idling in the driveway.
As you might expect, a general check of the fluid levels is a good place to ask your shop to start. Esp engine oil, coolant level, trans fluid.