Sunday 13 January 2013

How do you change your car's oil when you can't get the oil filter loose?

Here's something a bit different: cars. And oil changes. Cars are a ubiquitous example of the way various industries simplify their products for end users, not by making them fundamentally simpler, but by hiding complexity from the end user. Which is fine; until you have to change your oil.

You would have thought that car makers would have streamlined the oil-change process for end-users by now (where's the flap on the side of your car that lets you drain your old oil easily?). But on the contrary, the engine compartment of a new car is less accessible than that of a 27 year old car. I'm thankful that my car is 27 years old. But changing my oil for the first time still wasn't easy.

The mechanic who serviced my car last, used a rattle-gun to over-tighten everything as much as possible. Even parts like the oil filter that are only ever meant to be hand-tight. Rather than ranting about it further, I'd like to share a few tricks I came up with for getting stuck parts loose:

How to get your old oil filter loose

My oil filter wrench (the type with a metal band that tightens around the filter when you bend the handle) wasn't giving me enough grip, and at any rate, I didn't have room to swing it around far enough to make any progress. I didn't want to resort to the messy technique of hammering a screwdriver into it. Here's what I tried:

Give your filter wrench a sandpaper-surface

You can apply a coat of superglue to the inside surface of your filter wrench's metal band, then immediately sprinkle sand over the glue. When the glue dries you'll have a durable rough surface with plenty of grip (superglue isn't terribly flexible so leave gaps). Or you can simply glue strips of sandpaper to the inside of the wrench.

In my case, although the sandpaper seemed to help a bit, I still didn't have enough room to get my filter wrench tight enough around the filter.

Wedge a flat-head screwdriver between the wrench and the oil filter

Insert your flat-head screwdriver between your filter wrench's metal band and the filter. That way, when you bend the wrench handle to tighten the band, the screwdriver not only helps to take up the slack, it helps provide a concentrated point of pressure between the wrench and the band, giving you a lot of extra friction. In my case, it made all the difference, and the filter began to turn.

How to get the oil drain bolt loose on the bottom of your engine

My mechanic had put on the drain bolt on the engine sump impossibly tight. Too tight for brute force, even with a decent wrench.

  • First of all, you need a decent wrench, like a hex wrench (rather than a crescent wrench or spanner) that isn't going to slip off the bolt at every opportunity. The wrench needs to have a hole at the end of the handle.
  • You also need a ratchet tie-down strap. hook one end into the end of your wrench (or thread the strap through the hole until the hook stops it pulling through any further). Hook the other end to a solid part of your car's frame (if you can flex it by hand, it's not strong enough), so that when you tighten the ratchet, it will pull the wrench anti-clockwise.
  • Don't use an elastic strap under any circumstances. It won't withstand the tension you're about to subject it to, and when it snaps, it could do you a very serious injury.
  • Gradually tighten the ratchet. (As a precaution, just reach under the car with your arm when you do this, keeping your face and as much of your body as possible out of the way just in case something flies loose.) When the strap has enough tension, the wrench should very slowly and gradually begin to turn.


Other tips

  • If your oil filter and drain bolt are readily accessible, see how tight they are before you do your oil change. There's nothing worse than having your engine warm and everything ready to go only to realise that you can't get anything loose. If they're really tight, loosen them a quarter turn beforehand (don't worry, they'll still be tight enough to prevent any leaks).
  • Don't jack your car up if you can avoid it (it's safer not to). If you have your own driveway, chances are you have an inclined ramp between your driveway and the street. Back your car into your driveway just far enough so that your front wheels are at the highest point of the ramp, and the front end of the car is hanging over it. The slope of the ramp should give you a bit of clearance so that you won't have to jack your car up. (I picked up this trick from a professional mechanic.)
  • I like to disconnect the negative terminal of my battery, and pull out the distributor leads from my spark plugs, before I do any work on the car (as well as making sure the handbrake is on firmly!), just to be absolutely safe.  This will also prevent other people who have access to your car from unknowingly starting the car when there's no oil in it!
  • Wrap your oil drain pan in at least two layers of big plastic bags. Then wrap tape around the contours of the pan's spout so you can still pour the oil out of the pan easily. You won't have to clean the pan when you're finished.