Wednesday, August 29, 2012

Adding a little spark

We have two cars: a 2007 Toyota Matrix with about 80,000 miles, and a 1998 Toyota Corolla with about 140,000 miles. In some ways, the latter reminds me of Charlie Brown's Christmas tree.  It had a salvage title when we bought it in the late autumn of 2005, which meant that it was in a wreck but had been fixed up before being sold again. It was a big mistake though, because in the next few years we had more than our fair share of headaches due to a very poor reconstruction job. Thanks to a great deal of help from my dad, though, we have been driving it ever since and hope to keep it until something really bad finally goes wrong and it's just not cost-effective to keep it around.  I change the oil myself ever three-to-five thousand miles, and we don't really abuse our cars with any crazy driving habits either, so it's not out of the realm of possibility that the Little Corolla That Could will go to 200,000 miles or even beyond.  Last night, though, I finally checked something on the car that probably should have been looked at sooner: the spark plugs.

These suckers should have been changed about 20,000 miles ago
These little thingeys are responsible for igniting the gasoline during after the compression phase of a four-stroke engine, and if they are worn out they can cause a misfire or make it harder for an engine to start.  Ideally the gap between the electrode and the contact on these spark plugs should be about 0.04 inches, which you can test using a gap tester (the millenium falcon-like disc in the above photo) like so:
Most spark plugs have one elctrode. These have two...for twice the craziness!

On these worn-out spark plugs, the gap ranged from 0.05 to 0.06 inches, which might not sound like a whole lot but over time it can result in poorer engine performance, lower mileage, and increased emissions.
Gap tester or movie prop? You decide!
Testing these things is pretty simple: just stick the gap tester between the elctrode and the contact, and turn until it won't move anymore.  I should also note that getting the spark plugs out of the engine is super easy, provided you have a spark plug socket.  I have a Craftsman tool kit that includes such a socket, but I don't know if this is standard for these tool kits anymore. If not, you'll have to buy one separately :( Basically it's just a longer 5/8" socket with a rubber insert to help pull the spark plug out of the engine once it's loosened.

Anyway, once the spark plugs were all out I popped in my new set of  NGK's I bought for about $30, or around $7.50 each. There are less expensive options, but in the dead of winter when I'm trying to get my engine to turn over I'd rather have the peace of mind that comes from knowing I didn't cheap out on spark plugs.

Just to clarify: this is the box the spark plugs came in. Not the actual spark plug.

All in all the operation took less than 20 minutes, which isn't too bad considering it saved a lot of future headaches down the road. Get it...down the road? Bwa ha ha!

1 comment:

Steve said...

Your spark plug gap test reminds me of the Lincoln's Head Penny Voodoo my dad used to do on the tire tread. I think car repair is half magic.