Examine the engine’s exhaust manifold(s) for signs of cracks, leaks or stains. Stains could be from continual oil drips from a leaky valve cover gasket or other component, and cracks or blown-out exhaust gaskets could create dangerous exhaust-gas leaks. You can listen for sounds of an exhaust leak when the engine is running, or look for gray, white or black streaks on the cast-iron exhaust manifold. The streaks should lead you right to the crack or leaky gasket.
Brackets and adjusters for the various belt-driven engine accessories should be examined for any looseness, missing bolts, or cracks. Broken or loose brackets can cause accessories like the fan, power steering pump, water pump, alternator and air-conditioning compressor to not only lose belts but even fail before their time due to running misaligned.
If the vehicle you are examining is a front-wheel-drive car, then pay close attention to the boots on the CV (constant-velocity) joints. Most cars have an inner and outer CV joint on each side of the vehicle (left and right driveaxles), each of which is covered by a rubber boot. The CV joints are expensive to replace, and are packed with grease, and the rubber boots protect them from dirt, corrosion and moisture. Check the boots by hand by flexing or squeezing them to look for cracks or tears. A torn CV boot that has all of the grease from inside is a signal that the joints will need replacement shortly due to the invasion of dirt and moisture. Depending on the make and model of the vehicle, you may be able to check the CV boots from the engine compartment, otherwise, check what you can from above and do other CV joints from underneath the vehicle.
If you’re looking at a private-party car that hasn’t been detailed, the condition of the car’s battery may indicate what kind of maintenance the vehicle has been accustomed to. Often motorists pay no attention to a battery until the day it malfunctions and the vehicle is stranded somewhere. First look at the condition of the battery terminals and posts. Are they clean of covered with fuzzy corrosion?
- If you see dark color when you drop some of the brake fluid on a white card, the fluid is old and/or contaminated and should be replaced.
- Many newer vehicles with manual transmissions have a hydraulic clutch system – its master cylinder (arrow) should be near the brake master cylinder
- If from the engine compartment you can access any of the drive axle boots on a front-wheel drive car, do so while checking the engine, otherwise do it during your under-car checks or ask your mechanic to check them.
- This situation on a battery post is a sign of maintenance neglect – an owner who routinely had the hood open for servicing and checking would have found and fixed this corrosion before it got this far.