Carbon buildup on the top of the piston is common. Over time this can lead to symptoms varying from light ticking to knocking noises. Performing a fuel injector cleaning procedure can often help the condition by removing some of the piston top deposits.
Car problem reports
Problem with your car? See what our experts say or submit your own.
Most reported 1991 Dodge Shadow problems
Vehicles equipped with a 4 cylinder engine may develop a no start or stalling condition, most commonly caused by a failed distributor pickup plate.
Erratic operation of the speedometer may be noted on vehicles equipped with a passenger side motorized seat belt. This is generally caused by a failed Passive Belt Control Module (PBCM). Our technicians tell us that if the speedometer functions correctly with the PBCM disconnected the PBCM should be replaced.
Automatic transmissions can exhibit a variety of shifting and noise concerns due to failure of internal parts. Our technicians tell us that a complete inspection of all internal parts should be performed if the transmission is disassembled for overhaul. Numerous updated part are available for this transmission.
On vehicles equipped with manual transmissions a squeak noise may occur when shifting into or out of gear. Our technicians tell us that in most cases replacing the shifter assembly will correct this problem.
The connector on the input and/or output speed sensors on the automatic transmission may become damaged causing intermittent loss of speed control. There are wiring repair kits available to repair this issue.
Vehicles may develop a start and die out condition or a transmission that defaults to second gear. Our technicians tell us that the transmission control module (TCM) may be at fault and require replacement. If the TCM is replaced the pinion factor should be reset and the quick learn procedure performed.
The manual transmission may become locked in neutral or reverse after shifting out of reverse. Our technicians tell us there is a stronger reverse detent spring available to correct this issue.
4 cylinder engine timing belts can be affected by driving in very hot climates. Our technicians tell us that replacement should be considered before the recommended 60K interval. Replacement timing belts have been designed for greater durability. It is also recommended the belt tensioner be replaced whenever the timing belt is replaced.
4 Cylinder engines may exhibit an erratic idle with the Check Engine Light illuminated. These conditions are most commonly present during cold engine operation in rainy weather. Our technicians tells us that there is an updated idle air control valve available to correct this concern.
4 cylinder engines may develop driveability issues and illuminate the Check Engine Light due to engine vacuum leaks. These vehicles use plastic vacuum lines which can become brittle due to heat and age. Care should be taken when replacing these lines as some may have a restrictor orifice molded inside. If lines are replaced without including the restrictors driveability issues will remain.