Engine Turbo-charger problems of the 1997 Volvo 850

This complaint applies to two years of the same model 850 Volvo,a 1994 and a1997t. Both cars had main oil seal failures. The 1994 car was a high mileage car with about 180,000 miles it started leaking at 150,000 miles and progressively got worse to point of one to two quarts a day. We decided to trade the car in and purchase another 850 because we had good service out of the car except for the oil leaks. I was honest with the dealer why I was trading in the car. The dealer was the local dealer for dayton ohio,frank z imports. The salesman failed to inform us that this is a chronic problem with the 850 model. Now the 1997 model started leaking at 90,000 miles. I discovered this is a chronic problem when I researched complaint files. I also discovered this has caused several engine fires due to oil leaking on hot exhaust pipes . I feel the dealer or mfg. Should be responsible for these repairs. To correct this obvious mfg. Problem. I am very disappointed with the car mfg. And the dealer for not being honest about this problem. I used to praise Volvo, for I am a aircraft mechanic of 25 years. I will no longer do so and if asked I would not recommend a Volvo or frank z imports.