How A $30 Laboratory Test May Have Just Saved My Engine's Life

One thing I didn't mention in my writeup of the wacky Gambler 500 road rally was that my Jeep overheated, and it was all my fault. When I returned from the rally, I frantically shipped off an oil sample to a lab to have it tested. That decision may have saved my engine's life.

A few weeks ago, I took my $US600 Jeep Cherokee to a loony, junker-filled road rally in Michigan called the Gambler 500. The Jeep performed admirably, except it overheated once due to user error (as a former cooling system engineer, I have to point out that my cooling system was on point).

It happened during the first night of driving; I had just arrived in northern Michigan, and the directions were sending me through the woods on a bunch of rutted, sandy roads. Those sandy roads all led to a large sand-covered opening along a hillside:

Photo: Tim Telgenhof

So naturally, I popped the Jeep into four-wheel drive and hooned the crap out of my trusty steed, kicking up sand and revving the venerable 4.0-litre inline six that had faithfully taken me 4,000 treacherous miles to Utah and back.

Getting up the hill, though, proved harder than I thought, as the engine began running out of steam as it tried overcoming both gravity, and the mounds of sand that those front tires kept wanting to push out of their way. My foot had the gas pedal mashed to the flimsy sheet metal acting as the replacement floorboard, but the Jeep slowed to a crawl.

Then all the excitement came to an end, because I glanced at my temperature gauge, and it was pegged in the red. Then I looked near my shifter, where my electric-fan toggle switch is mounted, and my heart sank: I had forgotten to turn it on.

Panic set in. I put the car in park and let it idle, giving it a few revs to get up the coolant flow and mechanical fan speed, but the temperature wasn't dropping, so I shut off the motor, and it immediately began to heat soak. I stepped out, popped the hood, and feared the worst.

Coolant hissed as it boiled over from my radiator cap into my recovery bottle. The fluid in the bottle was brown, which worried me, though I wasn't sure how clean that recovery bottle was in the first place. I checked my oil level; it was fine.

I let the Jeep sit for about 10 minutes, after which point, I cranked the motor back on, the coolant temp dropped, and the engine ran great. I drove the rest of the rally, and even towed my friend back for 161km; the Jeep was marvellous.

I kept an eye on my oil and coolant levels throughout the trip, and everything looked OK. In general, a cracked cylinder head or a bad head gasket would lead to a milky, overly-full oil level, and a low coolant level. But everything checked out.

Still, as someone who's been wrenching on Jeep Cherokees for many years now, I know how prone 4.0-litre heads are to over-temps. I had this hunch -- or maybe you could call it paranoia -- that, even though all systems looked good, there was something was wrong. So I sent an oil sample in to Blackstone Labs, and for 28 bucks, they broke down its contents.

I've shown you what one of Blackstone's reports looks like in my post about my brother's 12,000 mile oil change, and this report exactly the same thing.

Blackstone's test can give you an indicator of major engine parts wear (which you can derive from the iron, aluminium and chromium parts-per-million readings), bearing wear (copper, lead, tin), air filter effectiveness (silicone), resilience of oil wear additives as well as viscosity, and even whether you've got coolant in your oil.

This last bit is the important part, and indeed, my hunch was right; unless there had been a pre-existing leak (which I doubt), my bone-headed mistake had cost me a cylinder head or just a gasket (my bet is on the head). Both sodium and potassium, two antifreeze inhibitors, are present in alarming quantities.

At 142 parts per million, there's over twice as much sodium in my oil as there should be, and at 51 parts per million, there's over 15 times more potassium. This, Blackstone tells me in the comment, is not a good sign:

Unfortunately sodium and potassium are present, and those elements are markers for coolant. The good news is that you caught it early. The coolant hasn't affected the wear.

So that's bad news, but also good news. I can fix this head or gasket problem, and my bearings will be none the wiser. My engine could come out of this completely unscathed, and all because my I let paranoia drive me to send in this oil sample.

I'm relieved. But also a bit bummed.



    This annoys me. It seems like most other countries have cheap motor Sports to get into but there's nothing in Australia. Every motor Sport here costs at least 30 thousand to get into. No wonder so many people are frustrated and get their his on the street. If I want to play football, Cricket, golf, soccer or any other sport, there's heaps of places I can go to any day of the week but if I want to go motor racing, nothing. Australia sucks for motor Sports big time.

      Is that true? I thought track days are pretty common and pretty cheap. Going to the drag strip is also cheap from what I hear.

        It's not true. There are plenty of cheap alternatives. But by the power of scaled economies everything just appears more expensive here.
        Also, knowing where to look to find your activity is a boon in itself.

          In England you can join rally cross and you only need a 1500 dollar car. They have the same thing in sweden where no cars over 5000 are allowed in. There's nothing here at all like that. Drag strips and track days aren't open every weekend and both those places are useless in a heap of shit car. If you name some other motor Sport here in Melbourne that I can enter with a 1500 dollar junker, please let me know.

            Due to the size of our country and low population you aren't going to see an abundance of events available in every town/city/state. Some travel is going to be involved. But 2 rallys I know of off the top of my head are The Sh*t box Rally and 24hrs of Lemons Australia.
            The best bet is to scour Gum Tree and go from there. I bet if you found a spot on some farmers land and advertised you could make you're own event in a heartbeat.
            I'm in WA so can't help ya with your Melbourne dilemmas sorry fella. I know a few lads here who race their sh*tboxes on mates farms. Bit rare though these days. As we grow up we end up with more money but less time :(

        Track days and drag strips are only good if you've got a good car. I'm talking 1500 dollar shit heaps. Top gear did a story about rally cross in England and it would cost you the same as a golfing bag with clubs. Entry was only 50 dollars. In the US there's tons of ultra cheap motor racing.

          When I went to a track day, there was an old dude with a $300 motorbike and he was lapping all the young ones. He had his knees scraping the corners and everything. You don't need an expensive vehicle to have a fun time at a track day.

      Didn't cost me anywhere near that do do motocross or hill climbing.

        I take it you mean by motorbike. How much did the motorbike cost ? 1500 ? But I'm talking cars not bike

          For hill climbing the car cost about 3k (r30 skyline) then tyres misc parts. Cost about 5ish grand.

    You had your fans on a manual switch and not on a thermostat. I'm sorry but you sir are an idiot.

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