Need help!! car redlining when its not suppose to??

[e30_OneLove]

So i have a 89 325is and recently my car has been redlining?
Before i could reach high speeds but now ill reach 100mph and the rpm's will go from 5k to redline and the engine bogs out and i cant go any faster. Today it did it to me at 80mph and redlines again. Last time it did it twice and I had a really big back fire:(
I dont know if its the transmission slipping or what could it be?
BTW the car is automatic, and i swapped the engine from a 91 325i'

If you guys can help me it would be great:D Thanks

[jlevie]

Are you hearing the engine speed actually increase to the redline, or does the tach go high without an increase in engine speed? The former would be a transmission problem. The latter would be a problem with the CPS, engine harness, or DME.

[paperplane94]

slippage.

[jlevie]

If it is slippage, the transmission is about to quit working.

[e30_OneLove]

yeah it doesn't increase speed just redlines and i loose speed and than it responds but there is no point on stepping on it cus it will do it again.
Oh okay damm well perfect time to do a 5 speed swap, thanks guys.:D

[TobyB]

you COULD check the trans fluid level before you throw it away...

t

[Bretts85E30]

Yeah my trans lines seep so when the trans gets low after a few months it slips a Lil and I fill it back up and its just like new again

[jeffnhiscars]

Yeah my trans lines seep so when the trans gets low after a few months it slips a Lil and I fill it back up and its just like new again

So you knew when you posted this that the problem was a bad hose causing low fluid.

You are not the OP..my bad !!