Vehicle Inspection vs Diagnostics

Home  \  Repairs & Maintenance  \  Vehicle Inspection vs Diagnostics

hi, i am buying a used car and want to take it to a mechanic to see if there is anything wrong with the vehicle. problem is i dont know what i should do. have a inspection done, or a diagnostics? can some please explain the difference to me, thanks

posted by  aspen

Diagnosis is the systematic resolution of a symptom or set of symptoms to its underlying cause. Inspection is the evaluation of a vehicle's condition and/or roadworthiness. Consider the two like this... If you have something bothering you and you go to the doctor to get it taken care of, the doctor must diagnose your problem in order to come up with a proper cure. On the other hand, when you go in for a routine physical, with no particular complaints, the doctor must inspect you to determine your physical condition... :)

Naturally, a complete inspection may actually include certain diagnostic routines, such as a test drive or checking for any stored service codes.

posted by  cpprioli

thanks, that helps a lot. do you think it would be nessesary to run a engine compression test on the vehicle, the car has like 65,000k miles on it.

posted by  aspen

Save your money. Compression tests are usually only done on performance vehicles during intervals like that, something where it actually matters that they aren't a five pounds off. Or if of course the car has a blown head gasket or hole in the wall or if the rings are buggered etc. you can tell all those things by the way it runs though, it'd have a miss. It can't hurt to do it though especially if it's a 4 banger or I5 or I6 or RWD, if it's a V6/8 FWD, cost more than it's worth. Chances are very high you aren't going to find anything if you don't hear anything odd.

posted by  88GrandPrixSE

You should have the car fully tested, period.

In the engine bay you should have the battery tested, the alternator tested, a compression test, a vacuum diagnostic, an AFR test, coolant tested for oil presence, the oil tested for acids and solids and water system pressure tested. It's you money they are taking so spend it wisely.

Have the car put on a hoist and the transmission, suspension and brakes checked and tested.

posted by  Wally

Your Message