inh
Explorer Addict
- Joined
- June 30, 2005
- Messages
- 1,299
- Reaction score
- 5
- City, State
- Springfield(ish), MO
- Year, Model & Trim Level
- '00 XLS
5r55e high pressure spikes at WOT (codes P0741 and P0743)
Today my transmission started doing funny things when downshifting or accelerating at WOT. It will spike to 500-600 PSI (estimated, based on the needle pegging on my 0-400 PSI VDO trans pressure gauge) when accelerating at WOT from a stop. Most of the time, when it downshifts to second or third, under WOT the needle will peg as well. It even does it on the highway when downshifting to maintain 70 MPH. It goes well passed the 400 PSI mark and will sit there for a few seconds before dropping back down. My pressure gauge has an electric sender and functions fine otherwise, so I don't think it's a wiring issue.
Background: Installed a sonnax increased ratio boost valve, increased pressure spring and the updated separator plate a couple years ago, along with an external trans cooler and filter, and filled with mobile 1 ATF. Hasn't been changed since (I know, shame on me...)
I planned on flushing the system and changing the external filter here in a couple weeks, but maybe doing that sooner might help un-stick whatever seems to be sticking? I have a feeling I need to drop the valve body though..
Today my transmission started doing funny things when downshifting or accelerating at WOT. It will spike to 500-600 PSI (estimated, based on the needle pegging on my 0-400 PSI VDO trans pressure gauge) when accelerating at WOT from a stop. Most of the time, when it downshifts to second or third, under WOT the needle will peg as well. It even does it on the highway when downshifting to maintain 70 MPH. It goes well passed the 400 PSI mark and will sit there for a few seconds before dropping back down. My pressure gauge has an electric sender and functions fine otherwise, so I don't think it's a wiring issue.
Background: Installed a sonnax increased ratio boost valve, increased pressure spring and the updated separator plate a couple years ago, along with an external trans cooler and filter, and filled with mobile 1 ATF. Hasn't been changed since (I know, shame on me...)
I planned on flushing the system and changing the external filter here in a couple weeks, but maybe doing that sooner might help un-stick whatever seems to be sticking? I have a feeling I need to drop the valve body though..