A basic understanding of the magic … of the diesel

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I have a confession to make. I don’t know what about 90 percent of the little gauges on the dash of the truck mean. Let me clarify, I don’t actually drive the truck, so I’m kind of exempt from really needing this knowledge for anything other than having a clue as to why George might be tapping one and saying, “Come on, baby.”

And guess what? I’m not the only one who doesn’t know what the gauges mean. I follow several of the “newbie” threads on Facebook – there are a lot of people who aren’t certain what they all mean, and a lot of them are driving, which is kind of scary to me. I don’t think drivers should have to know how to tear their engine down and fix it, but I do think they should know what all the gauges mean. I can’t tear an IV machine down and rebuild it, but I have a basic understanding of how it works and can troubleshoot until I get the flow correct – you get the idea of the parallel I’m making here.

So when I was offered the opportunity to learn a little about a diesel engine and how it works with all the little gauges by one of the best in the business, I was honored and more than a little scared.

“Let me show you a thing or two about a diesel engine…”“Let me show you a thing or two about a diesel engine…”

Bruce Mallinson of Pittsburgh Power is all about educating drivers (and anyone else interested) on their engine performance and how the machine actually works. When he asked me if I wanted to learn a little more about the engines, I felt like Merlin had offered to give me lessons on magic.

“Bruce, I would love to learn more. I only hope you don’t realize how very, very stupid I am about the whole thing and give up on me.”

“I think we should start with how a turbo boost gauge and the exhaust gas temperature (EGT) or pyrometer can help you diagnose engine problems.”

I immediately felt the same terror I felt in nursing school when the instructor breezed in one day and said, “Today, we’re going over Angiotensin II receptor blockers, there will be a test tomorrow!”

This is my face when I hear things like that: O-o

Turns out, Angiotensin II receptor blockers are just blood pressure meds, and they’re pretty straightforward in what they do — they just sound really scary. Same with the pyrometer.

“If your turbo boost is down by 8 psi, then the EGT gauge will be up by 200 degrees. Fuel mileage will also be down and you could burn a piston.”

Nurse brain translates and equates this to: if you have arterial blockage, your blood pressure will be up by a significant number. Your entire body system will work less efficiently and you could have a heart attack.

Easy enough.

“If the boost is low and the EGT is higher than normal, we have an air restriction to the turbo, such as a dirty or wet air filter, or a failing turbo, or a leak in the charge air system, crack in the charge air cooler, loose clamp, or a hole in the charge air hoses, a leak in the tube that takes air to the air compressor, blown intake manifold gasket or a crack in the intake manifold.”

Nurse brain: Air is important to any and every machine, and if it’s not getting air properly, it’s going to turn blue, foam at the mouth, and die.

So now I know at least one small piece of the vast compendium of information Bruce has to offer, and here’s the most important thing, I understand it. That’s huge. I doubt I’ll ever be a diesel mechanic, but just understanding that one little thing will make it so much easier to learn more.

I so appreciate the time taken and patience Mr. Mallinson has had with me, and I look forward to learning more. How terrifying would it be to pull into a service bay at a shop and have me pop out to run a diagnostic? I can take your blood pressure while we wait …

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