Cool McCool's Garage

Last night I drove the Diamond T to the Gilmore Museums first “Cruise Night” after I got home from work.  It runs terrible when it warms up, but I figured I could make it 2 miles to the museum.

I did, but it was running awful, and again it had yakked up some coolant onto the right front fender.   Sigh.  It still drew a crowd among the few remaining there, and I made it home, so I guess it was a success.

When I got home, I quickly found the source of the antifreeze was the lower radiator hose, which has a pinhole in it.  With thermostat in, the engine comes up to temp, pressurised the cooling system, and, Viola!  Spews coolant.

Plus, it runs TERRIBLE once it warms up.  Misfires, belches black smoke, but only from the left cylinder bank.  (Note, I replaced the 02 sensor on that side too, with no improvement.  In fact, now it’s worse).

So at 0700 I was out in the shop, pulled the right front wheel, drained the coolant, pulled the (almost inaccessible)  thermostat housing, and gutted it.  I then jacked up the left side, cut an access hole in the inner fender, in order to change plugs.  (Remember, start with the simple things first.)

Guess what?  Three of the 4 plug wire boots nearly fell off the plugs.  What the…

It seems that when I changed plug wires, back long ago, it was impossible to completely push them onto the plugs.  I THOUGHT I had them on securely, but no.  So, the plugs of course are black and fouled.  They must fire intermittently, but not once it warms up.

Could it be that simple?

Anyway, off to the parts store for a new hose, a new ‘stat and we’ll still go get a diagnostic port to wire in for scanning it, but I may have solved the problem.