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…”](https://img.overdriveonline.com/files/base/randallreilly/all/image/2015/02/ovd.Merlin.png?auto=format%2Ccompress&fit=max&q=70&w=400)
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 …