Oil Change - Mick's Workshop Tips 419

By: Mick McCrudden

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When an oil change goes bad

You're going to give you old motor an oil change. Put the car on jack stands, not bits of wood and trolley jacks. When you’re under the car doing an oil change and undo the bolt, a lot of folks like to think they get absolutely all the oil out. Now that may not be a good thing. Particularly if it’s running an external oil pump.

What happens is they leave the oil draining and wander inside for a cup of tea and a scone, two or three hours have gone by, and they’ll put their old Holden V8 sump plug back in, fill it with oil, turn the key and there’s no oil pressure. The light will come on, there’ll be rattling, and you know you’re in trouble.

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You might throw a pressure gauge in there and find nothing’s happening. That’s when the panic begins.

What we discovered was that way back when they first introduced the 253 with the external oil pump they’ll actually drain out and, once they’re completely empty, there is nothing you can do to it with oil to make it prime up again.

You can take the oil pressure switch out the side and fill it with oil, you can fill the oil filter with oil, and nothing will happen. Don’t panic.

What you do is remove the oil filter. You have four main bolts that go through to the block, carefully undo them. Then there are two small 3/8 bolts on the end. What you’re trying to do is open the pump without removing it. It’s no big drama if you do, just remember to use a new gasket when you refit it.

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What you’ll see inside is the pump drives. The front gear is the one driven from the cam and the other is the idler gear. What you do then is slide out the idler gear, then, as silly as this sounds, go and grab a jar of Vaseline.

Just pack the pump with the stuff. You can use grease, but I prefer Vaseline because it breaks down easier. Once you have it packed, slip the idler gear in, clean off the mating surfaces and put it all together. Put a smear of Permatex number 3 or similar on the gasket and pop it back together.

What the Vaseline does is to help the pump to create suction, which will enable it to prime itself. The old internal oil pumps that are in the actual sump – as on Clevelands and the like – don’t have this issue.

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A couple more tips for when you’re changing the oil: go mad and get yourself a new sump plug washer; If you have forgotten it, a little Teflon tape on the thread might do the trick.

Here’s the next little tip. If you look inside the oil filler and see milky condensation there, it could just mean your PCV (positive crankcase ventilation) valve isn’t up to scratch. So take it out and give it a clean, or replace it.

As time-consuming as it is, buy two oil filters so you can clear out the moisture. Drain the majority of the oil out, then add a 50/50 mixture of diesel and oil. This will give you a gentle engine flush that will clean out the condensation. Just idle (don’t rev) the engine for five minutes, then drain it out again and throw on the second filter – not forgetting to prime it with some oil.

It’s all fairly simple stuff, but your old banger will live longer as a result.

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