No, no. I'm not trying to start a hundred page thread on viscosity, but...

Today I did a semi-oil change.

"Whoopee bloody doo" I hear you say and yes, you'd be right, except it's only two weeks and probably 60km or so since the last one.

Last time I came to do this, my usual place was full of dead cars and they couldn't get me in, so I went around the corner to my local Caltex station where they offer the same service. I'm a messy bugger when it comes to oil. Always have been. The other reason is that changing oil in the Pit of Hell that is the apartment parking, ain't no fun.

I normally do changes around every 2,000km at most, as I do a fair bit of short runs coupled with hours sitting in traffic in +30 degrees, both hard on oil. My normal place sells Mobil 1 20W-50 so that's what goes in and for three years she's been happy. The new place uses Halvoline 20W-50, which is actually one of the brands recommended in the handbook. As an aside, 20W-50 is about the only grade you'll see here, we don't need cold weather oils.

So the first couple of days, all is fine and dandy, then I just catch the sound of a small rattle as an echo going up a parking ramp. "Strange" thinks I. The next couple of runs were only short and with no problems. Then, on Saturday, I take her for a fair trip and the noise is back, only louder. It definitely sounds valve train-ish and, of course, you start to imagine the worst. Then I get to thinking, "Wonder if she doesn't like Halvoline?" And let’s face it, always start at the cheap end, eh? To be honest as well, the idea of doing lifters and cam at this very moment does NOT appeal, either financially or location-wise.

This morning I'm awake at 3am and decided to test my theory. I've got 4 litres of Castrol GTX in stock, plus an unopened litre of Mobil 1 in the car so it's time for a Mess-less oil change. Slight problem is that the only thing I have large enough for this task is one of Madam’s casserole pans. Good job she and the Girls are in Tondo this weekend then!

The plan is to drop out 5 or so litres and replace. The filter would just make too much mess and, now 5.30am, I've only got that much new oil. I figure that replacing 76.923% of the oil should prove, or otherwise, my clutching-at-straws theory.

Down we go and under the motor. Carefully place pan and undo sump plug. Oil obligingly goes into pan rather than over the floor. I guess at quantities and stick the plug back in with only minimal arm drippage. So far, so good.

Using Ghetto Funnel (cut off top of coke bottle), throw in the Castrol then, whilst that runs through, place now empty Castrol bottle into pre-thought of carrier bag (to act as bund), gaffer tape the funnel to top and pour oil from pan. Success! Although the bund was a damn fine idea.

Top up with the litre of Mobil to level, tidy up, test drive.

The result? Now been out twice today and so far, not a peep out of it. Let's see how we get on, but I think I'll be dropping the whole lot out, filter and all on Tuesday.
And what conclusions can we draw? Well, it's a tad early to say, but either my ageing V8 really, really doesn't like Halvoline, or the Caltex station is using repackaged chip fat. Who knows?

I think the longest part of this project will be cleaning the pan. It's still got a slight sheen on the water in it.

You're a very brave man!

I would suspect they put some cheapo 5W-30 in that all modern cars seem to want rather than what you thought they were putting in. A few years ago I picked up a Daimler Double Six from the south of France to bring it back here. I was told it had been fully serviced ready for the run so I should have no problems. Within 100 miles the oil pressure had dropped and was only showing 15 psi when running and no pressure at all at idle. When I had set off it was showing 25psi at idle and 50 psi when running so all was not well. i phone the guy I'd picked it up from and asked what oil had been put in, 5W-30 was the reply. I managed to find somewhere that had 20-50 on the shelf and did a partial oil change over a drain at the side of the road and the oil pressure went back up to what it should be. It wasn't until afterwards I realised what would have happened if I'd dropped the sump plug.......

Quite possible, although I was stood there and watched them open the bottles.

On the other hand, I can buy a bottle of Martell Cordon Bleu, all sealed and boxed, for a tenner here with the contents bearing no relation to the labels. So why not oil?

It was interesting and I didn't give it a lot of thought at the time, but remember thinking that the oil light took a couple of seconds (literally, only that) longer than normal to extinguish.

Anyway, let's see how we get on. I'll be doing a full change, including filter, tomorrow with the guys I normally use.