I'm looking for a reality check here. Someone please help me out.
The other day I took my 2000 Voyager 2.4 in for an oil change at the dealer (Dealer A) who has done most of the oil changes on this vehicle. After waiting about 30 minutes, I checked on the progress of the oil change and was told that the threads in the oil pan were stripped, and they'd be happy to change the oil pan for ~250, or they could put in a rubber plug for about $10 extra. On the counter was the plug they'd removed from my car, which I visited and did indeed verify that the oil pan was stripped in a major way. I don't like seeing so much shiny aluminum where threads are supposed to be. This car has 80K on it so the oil has been changed 20-25 times in the past
4 years.Flash back about three months prior to the previous oil change at another dealer (Dealer B): I was told AFTER the oil change was complete that they'd had problems with stripped threads on the oil pan and had installed an oversize oil plug. The oil change prior to this had been done several months prior by Dealer A, so it's likely that they're the ones that damaged the oil pan.
Here's my issue. I can understand steel plugs in an aluminum pan and the possibility of damaged/stripped threads. I did a little research and find that the oil pan is tapped 1/2 x 20. The oil plug removed from my car was clearly stamped metric, and further more was clearly a regular metric oil plug that was a bit larger than my original 1/2 x
20 plug. I haven't yet determined exactly what size the plug is; that's for later today. I do know it's bigger than M12 x 1.5, likely M13 or M14. The tip of it (tapered) just fits inside a 1/2 x 20 threaded hole. This 'oversize' plug is clearly NOT what I'd have expected to see which would have been labeled a single oversize plug for 1/2 x 20, and should have had cuts in it so that it would be self tapping in the aluminum hole, with the same thread pitch as the original plug. Am I right?It seems to me that replacing a stripped 1/2 x 20 with a larger metric plug that's a) got a different thread pitch, and b) isn't a self tapping plug is a recipe for the kind of damage I've seen. I'm going to pay a personal visit to Dealer B tomorrow to discuss this with the service manager since it's their tech that caused the gross damage that IMHO would have been repairable with the correct oversize plug application. Someone's going to buy me a new oil pan, and it's NOT me.