Nice easy one for a first post I have been looking to buy a Prius for some time, all my knowledge is based on what I have read, I have never driven one or consciously even seen one that I can remember. They certainly are a tad expensive second hand but I have an opportunity to buy a faulty one. The fault is that under "heavy" acceleration the engine revs, it seems to disconnect from the drive system. My understanding (probably incorrect) is that there are no bands or clutches associated with the drive chain, a planetary set dictates which way power is transfered and electronics decide where the power comes from. My first thought was that this could be a problem with the traction control but as the engine revs up I fear this is not the case. I think that the problem may be associated with the electric motor drive system, allowing the engine to spin the motor, this only happens for a few seconds then the car will accelerate normally. It sounds very similar to "flair" where a slipping clutch or badly adjusted band in a normal automatic gearbox will allow engine revs to increase during a gear shift. I haven't seen the car and I do not have any more information about it. I do not know what questions to ask the guy that is selling it that will help me diagnose what may be wrong. The car is a 2002. I am really looking for some suggestions, it would be wonderful if someone had seen the same problem. I have no worries about fixing it if the problem is mechanical but an electronic fault worries me somewhat as the electronics are probably all sealed up and potted making any kind of diagnosis difficult. All input gratefully accepted and appreciated.
AFAIK the Prius has an 8 year warranty on the power train... Here is an excellent site to see what happens inside the HSD drive unit. http://eahart.com/prius/psd/
Sorry, but the power train warranty is 36 months or 36k miles. Only the Hybrid parts have the longer warranty (the tranny is part of the power train, not the hybrid system). JeffD
Jeff, I don't mean to be critical here, but were you offer'g your drive train warranty info for the USA or another country? AFAIK, in the USA the 3 yrs/36,000 mi. is for the bumper-to-bumper on the car (minus wear items (such as light bulbs, wiper blades, etc.), the drive train is 5 yrs/60,000 miles, rust through is 5 yrs/unlimited miles, & hybrid components are mostly 8 yrs/100,000 miles [except for the Calif emisions states (all of New England, NY, NJ, & CA) where it's 10 yrs/150,000 miles]. That's just the way I remember it (without the benefit of having my manuals near at hand). Ken (in Bolton,Ct)
What you describe may be normal. In a Prius engine RPMs are not a direct function of road speed. Can you find someone who already owns a Prius to ride with you or drive this one? They should be able to say quickly whether this one sounds and feels normal. In any case take this one to a Toyota dealer for a through check before you buy it. Prius are reliable but complicated; there is a vast array of possible problems that can only be diagnosed by Toyota's proprietary equipment.
I did wonder if it may actually not be faulty. One bit of information I missed out is that when the engine flairs the "hybrid" light comes on, whatever that means.
