About half year ago I've done comlete valve job and rings replacement on my 91' PT engine due to high oil consumption (about 1 qt for 400 miles) with about 200 Kmiles on it and made some improvemens in sealing and crankcase ventilation system. Bores and pistons were in tolerances. In my opinion, increased oil consumption and smoking were caused by completely clogged oil rings and drains in piston's skirt. Now engine runs like a charm -- easy revving, pulls hard untill 6,500 rpm (about 85 mph on the second gear, autotranny) and consumes about 0.5 qt for 3000 miles, passed CA smog check with all lowest readings. Week ago I've bought 92' V8QA 4.2L with 89 Kmiles and don't see much difference yet -- untill I'll put my dirty hands on it!
