By Gregory Grisham
I recently picked up my 2000 Nissan Sentra from the shop. I had the head gasket replaced. On the parts list was a new oil dipstick. I asked about it and they said the plastic top had separated from the metal stick. I told them that was the fourth oil dipstick that I replaced. It seems that the gasket around the top of the dipstick makes such a good seal that it causes the heat to be trapped which in turn causes the plastic pin holding the metal stick to become brittle (heat fatigue).
When I have gone to the dealer to get replacements for the previous broken dipsticks, the service person always says “That rarely happens,” to which I have replied “Then why is the part always in stock?” I have never received an answer to my question. Monkeys must not know what types of plastics to put in high temperature environments.