If your mechanic started the car, have him button up the valve cover. Then ask him to lower the oil pan and replace the worn out O rings in the oil pickup, so this doesn't happen again.
Then go out and drive the car like you hate it! 2nd gear will let you get up to 70mph. I forgot the year, if it is 1995, you cannot put it into L until you are over 25mph to stay in 2nd gear. Under 25mph will invoke 1st gear and you don't want to rev it very hard in 1st.
Don't let your son rev real high, he will forget how fast he is going and get nailed by a cop :)

Klaus
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The 164 has a new home, all I am left with are a 95 854T and a 98 V70R :)

The LMS has almost nothing to do with a lawn mower. It has everything to do with the oil pressure and lifting the hydraulic lifters. The reason for LMS: One needs to get the lawn mower out of the garage, but it is stuck behind the 5 cylinder engine. So, start the car, back it up a foot, and turn the car off. Not enough time to build up oil pressure, so when the lifters settle, they are not where they are supposed to be. Zero compression on ALL cylinders!

The only way to resolve this is to crank the bejeesus out of the engine, with the right foot mashing the gas peddle to the floor, until it finally coughs into life. The wide open throttle during crank actually tels the ECM to turn off the gas (flooded) so that the plugs don't get too wet.

This high speed cranking, because of little to no compression, will build up oil pressure and the lifters will eventually assume the proper lift.

I think your son had the car started for a nano second at the gas station and then it died. That would do it.

Tell your mechanic to read this post, charge the battery, and crank the starter for a couple of minutes, non-stop.

Klaus
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The 164 has a new home, all I am left with are a 95 854T and a 98 V70R :)