94 E420 Upshift Delay Questions
 

I recently had my car into the dealer for a CEL. They replaced one O2 sensor and the Upshift Delay Actuator in the tranny. When I first got it back I accepted the way it drove, but as time goes on I have more questions. I have only owned this one for 10 months so I am a little scared.

1. What temp does this delay work off of, engine, trans, exaust?
2. It delays all shifts when cold. Is is supposed to do this? The shift from 2nd to 3rd seems to be delayed even when warm.
3. Is there any way to disable it without setting off the CEL? I frequently turn onto highways and buisy streets when cold. It takes at least 20 minutes of idling to make it shift right away.

I think some of my problems may be related to a disfunctional thermostat
which keeps the engine around 60C.

I have been searching the site but I have not found anything specific to my year/model/issues.
I have learned many things the hard way before I found this site. Thank you all.

Based on the content of your reply/request I can only suggest that you resolve the engine temperature issue first. If it is a T-stat problem it can also reduce the frequent visits to the gas station.........:)

Your temp guage should it about 1 needle width over the 80 mark. You have a thermostat that is stuck open. $15.00 part 10 minutes to change it. You could be doing harm to your catalytic converter by not fixing this ASAP.

The warm up shift delay should go away very quickly after driving off. It also should shift to second anytime you hit 3,000 rpm even if the engine is cold.

Steve

yes your thermostat is causing the problem not to mention that your heater must be very puny.

I agree that the coolant temperature issue should be addressed first, but the upshift delay valve may need to be adjusted as well. The delay valve assembly includes the bowden pressure cable adjustment that many of us are familiar with, but there's also the diaphragm adjuster, which isn't as well known. If not adjusted correctly, the shift points can change.

I am going to change the thermostat this weekend if I figure out what engine I have. My heater seems fine, mpg sucks. I have adjusted the bowden cable to each extreme, and no change. I would like to try to find out more about adjusting the diaphragm adjuster because my shift points have definitly changed. The car will not shift out of first at any rpm when cold for at least 5 blocks.

Up-shift delay (1992-1996)
 

Noticeable operation of the delayed up-shift system varies between drivers because of the variables in the neighborhoods that we live and work in. People who live in a more rural area where surface streets have fewer stop signs may feel the delay operate once during their drive. People who live in neighborhoods with numerous stop signs on the surface streets will experience several delayed shifts. Before proceeding with anymore "adjustments" to the up-shift system get your engine temperature and your fuel mileage up first………:D