When buying a second hand car it is always important to check it thoroughly before purchasing one of the most common problems in used cars is that the exhaust is often over looked. It is also very easy to check over yourself if you know the right techniques, below are some simple things you can do to check the cars exhaust is in good working order:
Check for leaks
You can do this in a number of ways on of the most simple is to take some safety gloves and a cloth to the car viewing with you, you then put the gloves on switch the engine on and leave it running. Once the engine is running you just have to block the end of the exhaust with the cloth and hold it there for 5 seconds or so and listen closely for any hissing sounds or bubbling that's coming from the vehicle. If you do here anything abnormal then it could mean part or all of the exhaust system could need replacing, you can then judge the price you would want the vehicle knocked down to because of this fault.
These sounds could mean that one of the brackets holding the exhaust in place is loose or something is touching the main exhaust pipe. If this is the case then this should be seen to straight away as it can cause the exhaust system to fail prematurely and then have you incurring the cost.
Strange colour smoke comes out
This could be caused by a variety of things including an oil leak into the exhaust system if this was the case the smoke coming from your exhaust would be blue. This will be caused by a leak in one of the valves designed to keep the oil out of the exhaust cylinder has failed. To stop the leak from entering the system any more you can add an additive to the oil that will help prevent leaks in the system, because if the leak continues it could cause the valve its leaking in to fail and this meaning the valve would need changing all together. If the smoke is white then there is a chance it could be the same thing happening as above but with water or antifreeze and the white is caused by the steam.
One of the main problems with exhaust systems is that they rust fairly easily because of the water left in the system after the combustion, it's in the form of steam but then settles in the base of the exhaust system and can cause rusting if not maintained properly. One way to ensure that the system doesn't rust out again is to replace the steel system with a stainless steel one.
The exhaust is important to check when buying a used car because there are so many things that can go wrong with it, some things could be easily over looked but if you spot the problem before purchasing the car you may be able to get them to fix the problem for you or drop the price in accordance to the amount of work needed.