After steam cleaning the bottom of the engine, the problem with the oil leak turned out to be a crack in the oil pan. To everyone's surprise, the oil pan on our model of Dutch Star is made of a fiberglass composit material, not metal. Our mechanic told us that it wasn't a big problem to change the oil pan and the Dutch Star was left with him to order the new pan and install it.
Our mechanic contacted Cummins the Dutch Star's diesel engine manufacturer and was told that the original fiberglass pan had been replaced with a metal one. The new pan was ordered and it was found to have a slightly different shape, however different enough so that the original oil pump didn't fit in the new pan. So a new pump had to be ordered and installed. And finally when the new pump and pan were ready to be installed, it was found that the original 30+ bolts to fasten the oil pan to the engine were different and new ones had to be ordered.
After a week in the shop the Dutch Star is home again.
One of the things that we found this season in Mexico is that a PT Cruiser is not the ideal car for Mexican roads. They're very low to the ground and we had to be very careful when driving off the main highways in any town we were in and bottomed out several times.
I had been looking for a small pick-up truck with a manual transmission but with little luck. But last week a senior couple who live in our Escapees Park decided to sell their RV including their towed vehicle, a Subaru SUV that has not only a manual transmission but included the whole tow hitch assembly. So now we have another vehicle and will probably keep the PT Cruiser as a back-up not wanting to be in the same situation when our Jeep died on us last year and we had to borrow a car to look for a car to buy.