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08 Mar 2019


It’s been two years since the prescribing of medicinal Cannabis became legal in my home state of Queensland.

Undoubtedly the legislation and its implementation have not been without controversy.

Patients in Queensland cannot lawfully ‘smoke’ their prescription Cannabis.

It is also illegal to drive with any detectable trace of THC.

There are no psychiatric indications for the use of medicinal Cannabis, but I know a lot about it from my clinical experience with recreational users.

They prefer to smoke it because it is poorly absorbed orally.

They also often add tobacco to prolong their enjoyment and unwittingly increase their dependency risk.

Roman Catholic missionaries introduced tobacco to India in the 16th Century AD and it wasn’t long before enterprising Indians had invented a device called a Hookah.

Cigarette papers hadn’t been invented and a multi-stemmed Hookah could let users share their enjoyment of a smoke.

The water filter added to the ceremony of the ritual, but did nothing to filter out toxins, carcinogens and the like.

Oh, and a Hookah was also just the device you needed to smoke your Cannabis or Opium, as you do.

And it was a modern day Hookah that I would need to fix my car which has stubbornly stayed in limp-home mode since last month’s column.

Readers will recall that my car’s On-Board Diagnostic reader had detected a leak on the intake side of my diesel motor.

Such a leak would prevent my turbo-charger from adding an extra 6 to 8 psi of boost which is about 0.5 Bar.

More importantly a tiny air leak would cripple my engine by not permitting it to rev or accelerate so that all that my car could do is ‘limp home’.

I’d done my best to find the air leak by inspecting every hose and joint, all to no avail.

But filling my intake pipes with pressurized smoke might help me find the leak.

My home-made Hookah was made from a spray gun filled with baby oil heated by a Nichrome wire attached to my car battery.

The hot wire vaporized the baby oil which poured out of a pipe at the top.

I momentarily thought of taking a drag from the aforesaid smoking pipe as so many of my patients would, but the psycho-active effects of vaporized baby oil are not well-described.

Besides that the smoke was there for a reason, to find my leak, and I wasn’t wasting any of it.

Low and behold smoke was pouring from my air filter box through a big drain hole in the bottom.

But the air cleaner wasn’t usually pressurised and the hole was there to let water drain if I drove through a puddle.

After a lot gaffer tape and more smoke I found a tiny pinhole in the pipe between the intercooler and the intake manifold.

The pinhole was on the under-surface of the pipe and there was no way that I would have ever seen it otherwise from above.

The pipe was flexible and made out of some sort of modern version of rubber.

Oily air is scavenged from the top of the motor and transferred to the intake manifold via these pipes.

The oil tends to lie on the bottom surface of the pipes and rots the rubber, eventually forming a hole.

Very astute mechanics know to listen for the slightest hissing sound from these tiny leaks.

A new hose and a computer re-set meant that my car was out of limp-home mode!

Success, at last, until I switched my car off and saw the engine light back on the next day.

To be continued.

Safe motoring,
Doctor Clive Fraser

Published: 08 Mar 2019