Vintage Diesel Car Care, Part 2

When you return, let the engine idle for a minute or two while checking for excessive smoke from the tailpipe, fluid leaks, and any odd noises from bad injectors or other mechanical concerns. Our test engine was okay in the noise department, but exhibited a rather large fluid leak under the engine. It turned out to be a leaking fuel-injection primer pump—not a big deal.


The engine also rocked from side to side considerably while idling, although not actually misfiring. A bad fuel injector can cause this, but here we had to blame the low compression on the one cylinder. Now, THAT'S a big deal).

Torque Converter Test
You'll also want to check the operation of the automatic transmission's torque converter after performing these inspections. Find a flat stretch of clean asphalt with some room to move the vehicle fore and aft. To perform this test, first verify that the parking brake is working by applying it, then attempting to move the vehicle with the transmission in "D." Use relatively light throttle input at first, gradually increasing it until the vehicle moves, or you reach about half-throttle.


If it holds reasonably well (the vehicle does not move forward until you reach about half-throttle), and no abnormal conditions are apparent (like broken engine or transmission mounts—identified by exaggerated engine movement during loading), then shift the transmission to "P" and put a block in front of one of the front tires. Now proceed to the next step.


With the parking brake still engaged, put your foot securely on the service brake, and select the "D" transmission position again. Now you will need to push the accelerator pedal to the floor (full throttle) and observe the engine RPM. It's almost essential that the vehicle have a tachometer, although a good ear will suffice. If you have access to a portable diesel tachometer, using it will work better than your ear.