should car coil springs be renewed in pairs?

Ideally they should be replaced in pairs. Ignore the boll0cks about headlight alignment. The easiest way to see the ride height is level is to measure the distance between the lip of the wheel arch and centre if the wheel. All you need is a tape measure.

Springs, brake pads and shock absorbers should always be replaced as axle sets, ie both sides at the same time. The only exceptions are air springs which have no half- measures, they either work or they don't.

The tank: the headlight height is not a guide to level as they are adjustable, you therefore have to be certain that the lights were perfectly level before the work was carried out.

Ideally coil springs should be replaced in pairs. The new one will be stiffer than the old one on the other side. This can lead to "tilting" of the car and with bad steering and skewing when braking. If you're lucky you won't have much adverse affect.

Now you must get your headlamp alignment checked. It's the most accurate way of seeing is the old spring is compressing more than the new one. If the headlamp on one side is actually higher than the other then the car is tilted. If that's the case then you should replace the old spring too.

Shock absorbers and leaf springs must always be replaced in matched pairs without hesitation.

Yes - should be replaced as a pair. "isitme" is correct about the headlights - that is certainly not a way to ascertain whether or not the other spring is compressed!

I f you are flush you can but it isn't necessary, if you are getting noises from the repair job take it back it will be nothing to do with the other spring