Recently my car started overheating. After taking it to the shop, the informed me that I had either a blown head gasket or a cracked head. Instead of attempting the costly repair, I used a block sealant. This seems to have resolved my overheating problem. However, the same day I replaced the coolant in my car, the tranmission started acting up. After the car warms up, the transmission will not engage into Drive or Reverse, if I let it sit for a while, start it up, it will engage, but will slip a little. After checking the fluid levels, the fluid is overfull. Could the problem be caused from the motor overheating, too much fluid, tranny filter, or just the transmission is done. I have not had any problems with the transmission slipping until the car started overheating. The car has 141k. Please let me know what you think. Thanks.
Transmission not engaging on 1998 Cadillac DeVille
What does the fluid look like, is it a milky color? If so there could be coolant getting into the transmission due to a leaking transmission cooler inside the radiator. If the fluid look OK but is just overfull the you may have an internal transmission fault. Unless the problem is with the trans cooler It's pretty hard to make a connection between the engine overheating and the transmission problems.