Two simple hacks to make your engine last longer

Modern cars clog up on the inlet side, commonly. Not every car, but some. It’s a symptom, not a disease. Simply cleaning the inlet doesn’t cure the underlying problem…

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You live in a big city and you do lots of short trips with lots of cold starts, but you want to maximise the life of your engine and minimise repair costs. Dead easy.

What causes this gumming up of your inlet system, like some automotive atherosclerosis, especially in the aftermath of a pandemic, can be hard to diagnose.

But most of it is preventable. We’re talking about a symptom - the blockage. If you simply clean out the problem, that’s like taking Panadol for a brain tumour. It’s not that effective at curing the real issue.

Now, a lot of people will throw their hands up at this technical stuff and assign it all to the ‘too hard’ basket, but you own the vehicle, it’s your responsibility to maintain it, look after it, service it and generally treat it with mechanical sympathy.

These machines are complex, granted, but you can’t just turn a blind eye to this stuff because it matters in the context of when something goes wrong and you need a remedy. These systems exist and we need to come to grips with them. Make friends with your car.

The two systems which really matter in this case are something called PCV or ‘Positive Crankcase Ventilation’ and EGR which is ‘Exhaust Gas Recirculation’. What do these terms mean?

PCV: Takes oily vapours from the typhoon in the crankcase and stops it getting pumped out all over the bicycle rider next to you, or something, and burns it in the engine so it gets recirculated;

EGR: You might hate this, but it’s designed to increase volumetric efficiency at low engine loads; deal with it, it’s a net advantage, but there are feedback effects and this could be one.

When you take the vehicle to be serviced, it’s a good idea to specifically mention to the service manager, (or your mechanic, because obviously you don’t need to have the vehicle serviced at the dealer), that you want them to take a thorough look at the PCV and EGR to make sure they’re not presenting any potential problems and functioning properly. They should also have a look at the associated plumbing relative to these systems.

If these systems are all, seemingly, in good working order, but there’s still an evidentiary problem, then you could be suffering from an operational problem. Such as oil dilution…

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Know your engine, even just a little

What is oil dilution and how does it happen?

Essentially, if you do a lot of cold starts, your engine parts are not at their optimal size because they’re designed to operate at a particular temperature and metal expands when it gets hot, and then they fit just Goldilocks, and you engine operates better. It operates better warm anyway.

What happens is during cold starts is there’s these blow-by gases which blow by the piston rings and end up in the crankcase and fall into the oil. The main problem is water (a main combustion by-product), and unburned hydrocarbons, like unburned fuel gets down there as well. And if you don’t get enough time operating your engine at the ideal temperature, then your oil just gets filthier and filthier, and thinner and thinner.

So you get more circulating volume than the engine’s designed for, resulting in more oily residue sucking into the inlet, and it gets baked on by the EGR. That’s the crux of the problem.

Here it is in greater detail: Engine Oil Diluted With Fuel >>

You can sometimes confirm this problem for yourself if you park on a flat level spot and check the engine oil level routinely every morning before start-up. If the amount of oil measuring on the dipstick slowly incrementally increases, then you can be reasonably confident you have an oil dilution problem, and you need to do something about it.

The Solution to Oil Dilution

Some people will say, ‘Just fit a catch can’ or whatever, but that’s still a band-aid and you’re simply catching the vapours on the way to the engine. And diluted oil doesn’t protect your engine. So a catch can is a bullshit so-called ‘solution’.

You must solve the underlying core problem of the dilution itself by getting those contaminants out of your engine oil.

The way to do that is you need to get out onto the highway more often. Meaning, aim for once a fortnight, for about an hour, at 80-100km/h in those cruising, low-load driving conditions. This gets the engine operating temperature up, but it’s under low load. It’s not that hard to do.

Australian cars, on average, go 15,000km a year which is 300 a week or 600 a fortnight, and I’m only talking about about 15 per cent more than that, out on the highway. Pick a location, about 40km away, drive there with the family, you’ll have a nice time, eat ice cream, do an activity, come home. Job done.

But there is one more thing you really should do.

Prevention is better than a cure

Let’s say you’re down the track toward being a model automotive citizen, you’re free to get out on the highway once a fortnight, doing all the right things. But what’s it going to do for you?

It’ll allow all those volatile contaminants to be casually sucked through your engine and burnt and ultimately buggered off.

There is one more thing I strongly suggest you do if you live in the city and do this cold-start/short-trip driving thing, you probably have a 12-month service schedule. 12 months or 150,000km is pretty much industry standard now, and it’s a grudge obligation, you have to do it because servicing is prevention of any engine oil problems.

So instead of going every 12 months, do it every six months. Do a full service every 12 months, and every six months, just do an oil change. It is so effective at getting rid of any fuel, water and other contaminants out of the oil - the ones that can’t be boiled off.

It is so effective in the domain of prevention and ultimately you will make back every red cent you spend on that intermediate service, and you’ll slash the number of days the vehicle spends off the road in the dealership trying to bend its brain attempting diagnose some convoluted oil dilution problem which could’ve been easily prevented.

That’s it. Do these two things: a highway drive once a fortnight, and an intermediate minor service every six months.

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