I worry that it is doomed to fail. My colleague Bradley Brownell called me from the side of the road and told me that my "Holy Grail" 1993 Jeep Grand Cherokee had a large oil leak and he has been trying to replenish the engine as soon as possible. But the inline six cylinders have been used up, Brad is in a remote place, and he has no oil on hand. I suggested that he tow the jeep to the nearest town-I was worried that this phone would ruin my jeep.

After Bradley went to my home in Michigan from his hometown of Reno (where he bought a rare basic manual transmission Jeep Grand Cherokee on my behalf), I took the pipe fittings he used to block the engine . Leak from the engine. Instead, I plugged in a new oil pressure transmitter, then changed the oil and sent a sample of the used oil to Blackstone Labs.

The Blackstone report worries me a lot, because although Bradley poured in at least 18 quarts of cosmetic oil, the iron content in the oil I discharged increased.

"Iron is still high enough to mark...steel components are the main area of ​​concern," the report reads:

Cut all the wires. It is modular, including wire strippers, crimpers and wire cutters. It is specially designed to handle data cables such as Ethernet cables.

I sent this report to Dr. Andy Randolph, Technical Director of ECR ​​Engines. He is a NASCAR engine developer based in Welcome, North Carolina and has extensive industry engine development experience. Taking into account the good compression readings I found using the compression tester and the good oil pressure generated by the engine (and the lack of bearing material in the oil sample), we concluded that the biggest problem is the camshaft.

"[Good compression] means it is not a hole. You have oil pressure, so [bearing may be okay]... the rest is the cam tappet interface," he told me. "Either that's it, or there is nothing at all."

Does running the engine at low oil wear out the protective outer hardness layer of the cam? Was it the camshaft fragment that Blackstone found in the oil?

To find out, Randolph suggested that I send another sample to Blackstone after driving a few thousand miles. If the hardness layer of the cam is damaged, the cam wear will not only remain high, but will accelerate, and I will see a higher iron content in the oil.

I followed Randolph's suggestion and sent the sample 3,000 miles later. The result just came back:

"Iron looks much better in this sample," the comment began. Not only that, for a 4.0-liter Jeep engine that has traveled 3,000 miles, all pollutant readings are below average.

This is really good news! My camshaft is not broken! In fact, it looks like my engine is very healthy! It produces a lot of compression and solid oil pressure, and its wear rate will not be faster than it should be. The 126,000-mile engine of my beloved Holy Grail Jeep Grand Cherokee may only have half the lifespan!

As for where did the iron in the previous sample come from? I'm not entirely sure. Maybe it's the product of the long-distance driving of the vehicle for a long time? A seated engine loses some of its cylinder lubrication. Will this cause increased wear? who knows. Or it might have something to do with oil geysers; in any case, it doesn't seem to be a big deal.

However, this report is not perfect. Blackstone wrote: "This time we did find quite a bit of fuel in the oil, but... the fuel is high enough to indicate that there may be a fuel system problem." This is not a big surprise. , Because I noticed a slight tripping during my free time. I will run some fuel injector cleaner through the fuel system, although I bet the real problem is a broken sensor somewhere. Large exhaust leaks in the manifold may also affect my O2 sensor readings, causing my engine to pump too much fuel into the system. Anyway, I will fix it.

Before ending this article, I have a random question for you, dear reader: How do you think I painted the lower part of the front and rear bumpers in red?

In this way, the red color at the bottom of the door/sill plate continues to extend to the bumper. When I show this jeep on Concours d'Elegance, it will lose my creative point, but am I a bit digging into it? Anyway, this is just a random idea...