My supercharged 1995 Toyota Previa minivan loses power when turning corners and climbing hills. It has not yet come to a full stop but slows down almost to a stop. Our independent mechanic was unable to diagnose the problem when it first occurred in 1998 at 53,000 miles but suggested that we try using premium gas. That appeared to solve the problem but unbeknownst to us it was just masking it. The Toyota dealerS service rep who finally diagnosed the problem at 88,000 miles in November 2000, said that the problem is an engine defect (his word). According to him, the material which Toyota used for the engine block in the supercharged Previas was too soft so the engine developed secondary and tertiary ridge rings. As I understand it, these extra ridge rings cause the anti-knock sensor to cut power to the engine under certain circumstances. It is masked when using premium gas because premium burns hotter but he said that as the ridge rings become more pronounced, the premium gas will cease to compensate and we could lose all power abruptly. He stated that Toyota had issued a tsb about the problem, which has been subsequently denied by the national customer service representatives. The dealer has replaced the defective engine block for other Previa S/C owners whose vehicles are still under warranty but refuses to replace ours since the warranty has expired. The rep suggested that I should take the vehicle to a different Toyota dealer who wouldnT know the history of the car and trade it in for a new vehicle. Since that diagnosis we have not dared to drive the car beyond our community because we donT know when we will suddenly lose power. I filed an NHTSA complaint on 11.19.01 but never received a confirmation # or signature form. Today I talked to your hotline rep who said that the complaint must not have gone through so I should file it again.

- Vicksburg, MI, USA

While driving engine dies/no power and no acceleration, towed to dealer. Dealer put in a new engine at 31,000 miles. Two years later, the same problem occurred.

- Norfolk, VA, USA

Engine problems experienced since 10-Apr-96 (engine light, oil consumption/leakage), several attempts to remedy with replacement parts, however have failed. Mjs

- West Palm, FL, USA

Engine check light remains illuminated, indicating a malfunction within the system, cause unknown. Also the vehicle is consuming large quantities of oil.

- Wellington, FL, USA