Am I wasting my time priming the filter after an oil change?

Question

I have a 1994 Toyota Paseo with a 1.5L engine. Neither the owner's manual nor the factory service manual says anything about priming the filter after an oil change, but conventional wisdom (and answers to questions like this and this) suggest it's a good idea to fill up the new oil filter with fresh oil if you can manage it.

Problem is, on this engine, that's not possible. The filter screws sideways into the side of the block and, by the time you get the filled filter threaded and screwed down, most of the oil has tumbled out onto the ground. In the past, I've just started it up and let it idle with a bone-dry filter. The "low oil pressure" light remains on for the first 5-6 seconds of idling, which I never really felt good about.

Recently I concocted an alternate way to prime the filter, but I don't have any sense of whether it's a good idea, bad idea, or simply a pointless ritual. What I've done is as follows:

1. Install a new, dry oil filter. Coat the rubber gasket rim, of course, but do not fill it in any way. Fill the engine with the new oil.
2. Pull the EFI fuse, disabling fuel and spark.
3. Crank the engine for 5 seconds.
4. Let the starter cool off for 15 seconds.
5. Repeat steps 3-4 until the oil pressure light turns off. Usually it takes 3 cranks total.
6. Reinstall EFI fuse and start engine.

My rationale for doing this is that the cranking runs the oil pump more or less the same as idling the engine would. Given that there's no fuel/ignition, there's bound to be less strain on the crankshaft bearings. For the cam and tappets, 15 seconds of 200 RPM cranking is roughly the same amount of total movement as about 4 seconds of 750 RPM idling...

At the end of the day, is this method any better/worse than just starting the thing up normally?

Answer 1

There's nothing wrong with what you're doing, but it's not really needed. There will be enough residual oil at the bearings and wear points to keep everything in check until the oil pressure comes up. The best thing you can do for your engine is before an oil change, warm up your engine for a few minutes or so, then let it set for a few minutes to allow the dispersed oil to drain back down to the sump. This will ensure the bearings are good and lubricated before you restart after the oil change is done. This also warms up the oil a little bit so it will flow easier out of the sump, which means you'll also get more used oil out during the procedure.

Again, there's no real issue to what you're doing. It won't hurt anything, nor will it cause any more wear than any other way.