If you need to replace the engine in your car, changes are that you will be looking at second hand engines. Second hand engines can be an excellent, much more cost effective alternative to buying a brand new engine (if it's even still avalable), but you need to be aware of the risks.

When buying a second hand engine, there are some things you can check to increase the chances that you are getting a good motor.

First thing to do is to have a chat to the seller, ask what the history is, where it came from and why it was removed. If you can get a service history for the engine that is ideal. If it was from a car that was in a frontal accident, there is a chance that something got damaged, so have a very careful look at it, particularly the parts that sit towards the front.

A decent visual inspection will often give you clues as to the condition of the engine. Check for oil traces around the head and block - these won't necessarily mean the engine is bad, but you will probably have to fix a leak if they are there. Pop the oil cap and have a look inside and at the oil - is it black and grimy, or does it look clean and new? The cleaner it looks, the higher the chance the engine was well maintained.

Another thing you can check is the compression. Checking the compression on all cylinders will tell you if the cylinders, piston rings and valves are all in good condition. If any one of these are failing this test will show it. It could also reveal a potential head gasket failure.

As a general rule, when doing a compression test, you should see around 135 psi or more across all cylinders. A little bit of variation is ok, but if you are seeing significantly different numbers between the cylinders, then something is wrong. If the compression is 85 psi or less, you've got a problem, so stay away.

We at AA Wreckers sell second hand engines for Audis, Volkswagens, Saabs, Skodas, Volvos, Peugeots and Citroens. We make sure that any engine we sell is good, so you don't have to worry about getting something that's going to blow up on your as soon as you turn it on! Give us a call today on (09) 829 2618 or come in to see us at 50 Fremlin Place in Avondale to get your new engine!