I am looking at getting a 1994 Dodge Dakota with the V6. Original owner, approx 100K miles, extremely clean, records etc. While getting the oil changed, the owner told me that the "mechanic" said that he smelled exhaust fumes in the oil and that meant blowback past the rings. Is this true, and does that mean a necessary top end rebuild? Is that expensive?

 

I've got a '94 2WD, Auto, 3.9 engine with 73,000 miles, and it does have some blowby into the air filter. Doesn't seem to be a big deal, at least yet. Doesn't use hardly any oil between changes.