Signs of serious Car Trouble
There are four primary systems of concern in the modern automobile. Beyond these are components that are more for comfort and convenience and not critical to the car’s operation.
Engine
Unusual noise, smoke, vibration, fluid loss or loss of performance can be indicators of serious engine problems.
Light valve tapping may be a sign of dirty oil or a worn engine, but not an indicator of serious trouble. However loud rapping, especially one that is quiet at idle but gets louder when the engine is under load, is a bad sign. It could be a failing rod or main bearing.
Clouds of blue/white smoke generally mean coolant is entering the combustion chamber. This could mean a blown head gasket, cracked cylinder head or cracked cylinder wall; pray it is a head gasket. This would also be accompanied by rough running, lost performance and coolant in the crankcase. A head gasket can be replaced; a cracked cylinder wall means the engine must be replaced.
Vibration could be the result of a dead cylinder due to a failed plug wire or spark plug; not a big problem. However, if the plug and plug wire are not at fault a more serious problem may be at the root of the vibration. A compression check will identify a cylinder that has a leaking valve, head gasket or cracked cylinder head. Note that head gaskets sometimes fail in the narrow area between cylinders. This does not lead to a coolant leak but does cause a loss of compression for both cylinders. If the engine also exhibits a “pop” in the carburetor/air intake system, a leaking intake valve is likely; when the cylinder fires some of the burning fuel mixture enters the intake system triggering the air-fuel mixture present. Any of the aforementioned symptoms indicate major engine work is in the offing. Head gasket replacement at a minimum, a valve job or cylinder head replacement may be required.
Loss of coolant or oil can mean a serious problem is on the horizon, depending upon the location of the leak. An oil leak from the rear of the engine may mean a leaking valve cover gasket or a rear main oil seal. Not fatal but an annoyance for certain. However a coolant leak could, again, indicate a cracked cylinder head or leaking head gasket which would be more serious and require major engine work. Occasionally, on older or high mileage engines, a coolant leak will show up in the area of aplugwhich will have to be replaced.
Finally, a loss of performance can have serious implications. Hard starting and lack of power that is not accompanied by smoke or noise can be attributed to fuel system issues. However, loss of compression due to worn pistons, piston rings, leaking exhaust valve or a worn cam shaft can cause a power loss. It is also possible the timing chain has slipped, disrupting valve timing and hampering performance. Major work is again called for under these circumstances.
Transmission
A manual transmission will signal serious trouble with noise, difficulty in engaging a gear or jumping out of gear. An automatic transmission will begin slipping, hesitating between shifts and could also become noisy. Another sign of serious automatic transmission trouble is a change in the color and odor of the automatic transmission fluid (ATF).
A manual transmission is a simple device when compared to an automatic transmission. Loud whining noise from the transmission could mean a lack of lubricant, or worn gears or bearings. If the lubricant level is correct, a transmission rebuild may be in order. Hard shifting or the transmission jumping out of gear is a sign of a worn or broken synchronizer and a transmission rebuild is required. It should be noted that a clutch that is out of adjustment can cause similar symptoms. It can also cause the damage to the synchronizers if it doesn’t release completely. Clutch adjustment is a maintenance item that is neglected at the owner’s peril.
An automatic transmission uses a series ofgear setsthat are in constant engagement and well lubricated. Gear changes are accomplished by the application of hydraulic pressure to transmission clutch bands. Depending upon which section of the gear set is gripped by a clutch band determines which direction, and with what ratio, the output shaft turns. Inadequate hydraulic pressure will cause the clutch band, and the transmission, to slip or fail to shift. The hydraulic pressure must be sufficient and directed properly. Problems in the shifting spool valve, pump or the pump pick-up will cause shift problems. If a change of transmission fluid and filter does not clear up the shifting problem, serious problems are indicated. Another indication would be discolored ATF or a burned odor from the fluid. There are several possible causes, so any legitimate transmission repair shop will insist on a complete rebuild. This policy will ensure there will be no warranty returns.
Automatic transmission noise can be gear or bearing problems or torque converter problems. Removal of the transmission will be required to analyze these issues so unusual noise can be serious.
Differential
In general the automotive differential is a robust device and long lived when kept properly lubricated.
Gear or bearing noise from the differential is never a good sign. If the lubricant is up to the proper level and the differential is noisy there is some major work to be done. With the drive end of the vehicle on jack stands the car is put in gear and the engine permitted to idle. The mechanic will inspect the assembly listening for the precise location of the noise. With luck it might be a wheel bearing. If is in the differential and not the pinion bearing a rebuild is in order.
Suspension
Suspension problems are typically identified with noise, vague steering, unusual tire wear or vibration.
Noises such as clunking when hitting a bump are indications of looseness in the suspension, never a good thing. Worn bushings or shocks should be replaced. Although not serious problems from a safety standpoint, they could accelerate tire wear and cause financial hardship. However, if the noise is accompanied by vague steering, the worn components are likely in the steering system and this is clearly a safety issue.
Unusual tire wear is generally related to alignment or worn front end components. These can be safety related and should be addressed.
Vibration can be related to tire balance, worn wheel bearings or suspension components. If worn wheel bearings are the issue and it is on a front wheel drive vehicle, the problem has just become seriously expensive.
