Jim Grant's Tech Tips
VW Golf GL, Rough Running & Check Engine Light
'96 VW Golf GL has been sitting in the rain for a couple of days and when
I tried to start it, it wouldn't start. Finally it did start but when
I stopped at a stop sign it stalled. I started it again and drove a little
bit, then the check engine light came on. The light flashed a few times
and remained on. I feel the engine didn't have enough power. Could you
tell me what the problem can be?
likely that your vehicle was suffering from the dampness. The cause we
see most often related to your complaint is due to spark plug wires. The
insulator on the spark plug wires breaks down with time, engine heat and
oils. A good soaking dampness is all that has to be added to cause the
spark to travel everywhere but to the spark plug. A hard start condition,
rough running and stalling until the engine becomes hot is a good indicator
of ignition related problems. On '96 and newer vehicles the computer monitors
engine misfire and when spark is not going to the spark plug it's a misfire.
The computer will respond by turning on the check engine light. If the
computer determines that the misfire is damaging it will flash the check
engine light. In most cases once the engine reaches operating temperature
the moisture/dampness that was allowing the spark to wander is evaporated.
Once gone, the engine will return to normal, but the check engine light
will stay on. The vehicle will have to be driven a few times before the
computer decides that the problem is no longer a problem and turns the
check engine light off. My suggestion is ignition system service before
the dampness causes the engine not to start or strands you while driving
in rainy weather.