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.
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Repairpal verified 1991 Dodge Spirit problems
The AC/heater (HVAC) system may unexpectedly switch to the defrost mode when accelerating. This system is operated by engine vacuum and should be inspected for any vacuum leaks if this problem develops. There is also a revised vacuum check valve available to address this concern.
A slight creaking noise may be noted from the upper end of the steering column when turning left or right. Our technicians tell us that the repair is to remove some material from the upper steering column shroud.
A noise from the rear suspension may be noted at slow speeds over uneven road surfaces. This can be caused by a cracked or broken rear torsion bar. A damaged torsion bar will require replacement.
4 cylinder engines may develop a coolant leak from the water pump area. The sealant used on the water pump may degrade over time, newer models have an upgraded rubber gasket. Our technicians tell us that the o-ring where the water pump housing mounts to the engine block may also leak which can appear to be a leaking water pump.
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 powertrain control module (PCM) may fail resulting in a lack of AC cooling. The lack of cooling could be caused by evaporator freeze-up due to the AC compressor staying on continuously or conversely, not coming on at all. Proper diagnoses of the PCM should be performed before replacing it for this concern.
Alternator pulley misalignment on 4 cylinder engines may result in belt noise and/or the belt "walking" partially off the pulley. Our technicians tell us that replacement of the AC and alternator mounting bracket, alternator belt, and if necessary, installation of washers to align the alternator pulley may be necessary to correct this issue.
Vehicles equipped with a 4 cylinder engine may develop a no start or stalling condition, most commonly caused by a failed distributor pickup plate.
When driving through deep snow the serpentine belt may be forced off the pulleys. If pulley alignment is found to be OK a shield is available to prevent snow from coming in contact with the belt.
Engine oil leaks may develop from the following areas: Valve cover gaskets, cam plugs at rear of the cylinder head, cam seals, front crankshaft seal, and the oil filter bracket. Leaking seals and gaskets should be replaced. Due to mis-machining of the mating surfaces, as special gasket is required to correct the oil filter bracket leak.
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.
A dirty throttle body can cause a low idle speed resulting in a stalling condition. Our technicians recommend cleaning the throttle body at 15k intervals to help minimize this condition.