bought 1988 reatta, sight unseen, found that the transmission shifts great all the way up the gears, but bangs into second gear on the way down. someone told me that it could be a vacuum line or modulator. i can't find a broken line and am not sure where the modulator is. can the problem be something else? i also hear a rattling noise between the trans and the motor which goes away when i rev the engine. is this part of the problem? other than that the engine sounds strong. it has approximately 160k on it.