Friday, 14 October, 2005

The Death of a Truck

My truck died today.  Its death came as no big surprise, as I have known for a couple of months that it was on its last legs.  It was kind of interesting to see it go.

Back in June, the "Check Gauges" light started coming on when the engine was warm and idling.  A quick glance at the dashboard showed that the oil pressure was in the red--registering less than 10 PSI.  The guys at the shop I took it to said, in effect, "No problem.  These older model GM trucks do that sometimes.  Run thicker oil."  I'm no mechanic, but that didn't sound right to me.  I asked around a bit, talked to my brother in law who owns a auto repair shop, and then had the dealer look at it and confirm what I suspected:  the engine was worn out.  Oil just wasn't circulating well for some reason.  We did determine that it wasn't the oil pump causing the problem, and it was too expensive to do any more diagnostics to find the problem.

The nice thing about having a worn engine that still mostly works is that it's beyond repair.  Short of rebuilding the engine, there was nothing I could do to make things better and continuing to drive it wasn't going to make the eventual repair any more expensive.  So that's what I did.  For three months I drove the thing around town, revving the engine at stop lights to keep the oil pressure out of the red, and hoped every time that I could make it to my destination.  I would not have done this if I were commuting to work every day, but with me working at home most of my trips were non-critical.

On my way home today I noticed a light knocking sound that was new and the oil pressure started falling very near the red line even when at higher RPM.  By the time I was about five miles from home, the knocking was very loud and the engine was developing very little power.  I knew that this would be the truck's last trip on that engine.  The engine had "spun a bearing."  One (or more) of the bearings on the piston rods came loose from the crankshaft and is slapping around.  The affected cylinders now fire when the piston is not at top dead center.  It makes for some very nasty exhaust in addition to the noise.

I'm somewhat disappointed that the engine only lasted 120,000 miles.  The rest of the truck is in very good shape:  the body is straight, the transmission and the rest of the drive train are good, and everything else checks out okay.  The tires will probably last another 50,000 miles and I just had the brakes redone so they should last at least as long.  I want to keep the truck because it's paid for, in good condition, and because it's been very reliable over the years.  But I don't know quite how to evaluate the risks and rewards of replacing the engine.

The dealer gave me a quote of $5,600 to completely replace the engine.  It's always good to get the dealer price, as that gives you a high figure from which to work.  I'm waiting on quotes from some mechanics to sell me a "long block," which consists of a new engine block, pistons, rings, etc:  everything from the head gasket down.  I suspect that will be less than half of the dealer's "new engine" price.  Allowing for the unexpected, I figure that I can have the truck operational again for about $4,000.  Kelley Blue Book tells me that the truck, with a good engine, is worth between $2,500 and $3,000 on the used market if I sell it myself.  Here in Central Texas where small trucks are at a premium, it's probably worth a bit more, but $4,000 would be pushing it.  So by replacing the engine I end up spending more on the truck than the truck is worth.

That's one way of looking at the vehicle's value.  But its value to me is a more complicated issue.  A new truck would cost $20,000.  That's a lot of money for a vehicle that I'll drive maybe 400 miles per month.  A comparable truck on the used market will run me between $4,000 and $6,000.  I can probably get $1,500 or $2,000 for my existing truck if I find a buyer who's willing to do the work himself to put in a new engine.  I understand that there are many such people out there.  Buying a used truck and selling the existing one would probably end up costing me the same $4,000 out of pocket by the time I'm done.  The advantage of keeping what I have is that I know the vehicle's history.

The final thing to consider is what I call the aggravation factor.  At some point the mental pain of futzing with something becomes overwhelming and I am willing to spend money to make it go away.  A brand new truck has an aggravation factor of almost zero.  That makes it quite attractive.  It looks to me as though the aggravation factor for the used truck versus replacing engine is about the same.  On one hand I have to deal with the inevitable minor glitches that usually accompany replacing an engine.  On the other hand I have the problem of getting used to whatever idiosyncracies a used vehicle will have.  It sounds like a wash to me.

At the moment I'm leaning towards replacing the engine.  If you have any insight on the matter I would appreciate hearing it.