1999 S-80 Transmission problem

itflores · Post by **itflores** » 07 Apr 2009, 11:12

I recently purch. a 99 s-80. It has 112K ml. Fluid was sludge. I replaced the filter and evacuated all old fluid. The trans cooler was out as well and replaced with new radiator. Now it shifts well; problem is that when it warms up; it stays in 2nd or 3rd and does not pass 4k rpms; any suggestions?

Post by **MadeInJapan** » 07 Apr 2009, 15:04

Welcome to MVS.
Sounds like the sludge might have done more harm than you realize... or it could be one of the lock-up solenoids that's gone bad. Do you get any transmission codes when you read your trouble codes through the OBD-II port?

Post by **vegasjetskier** » 07 Apr 2009, 15:49

I think your car might be going into "limp home mode" once the transmission warms up. There is a temp sensor that connects to the computer that limits the power to the trans if the fluid gets too hot. Maybe your fluid is still getting too hot. Or, maybe the temp sensor is bad. Here is a PDF that shows the parts of the trans - the temp sensor is #25. You might want to try changing that out. Have you had any diagnostic codes read yet?

S80Transmission.pdf: (177.5 KiB) Downloaded 153 times