Tranny temp sensor
New User
Joined: Aug 2008
Posts: 20
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Meat thermometer did not work (didn't think it really would). Tried it after 20 mile trip home from work yesterday. Outside temp in the 70's trans temp close to 190, truck unloaded. Pan felt very warm to touch but both lines were luke warm. Could the lines be blocked to the radiator and cooler and if so what is the simplest way to check that I have good flow out and into the tranny? I have seen on the tru-cool website that you can trouble shoot by pulling various lines to see if things are flowing. Will that method work on this e40d? Want to solve this issue before I haul anything large. Thanks.
Frmr Ford Trans Engr
Joined: Aug 1999
Posts: 24,731
Likes: 2,658
From: SE Florida
There is a way to check the flow.
Warm up the trans. You can't do an accurate check on a cold trans. Remove the cooler line where it attaches to the rear of the trans. Aim this into a bucket. Have a second bucket next to the first. Start the engine. Once there is a solid fluid flow into the bucket, move the line to the second bucket for exactly fifteen seconds, then move it back to the first bucket and shut the engine off. If there is at least a quart in the second bucket it passes. Less than a quart is a failure.
If fluid sprays out of the trans where you removed the line you have either a plugged cooler or a failed bypass valve.
Warm up the trans. You can't do an accurate check on a cold trans. Remove the cooler line where it attaches to the rear of the trans. Aim this into a bucket. Have a second bucket next to the first. Start the engine. Once there is a solid fluid flow into the bucket, move the line to the second bucket for exactly fifteen seconds, then move it back to the first bucket and shut the engine off. If there is at least a quart in the second bucket it passes. Less than a quart is a failure.
If fluid sprays out of the trans where you removed the line you have either a plugged cooler or a failed bypass valve.
New User
Joined: Aug 2008
Posts: 20
Likes: 0
Got my hands on an infrared temp guage and noted the following. After 25 minutes of driving Trans Temp Guage showed 200F. Took IR reading of lower pan next to temp sender 150F, at sender 160F, at test port (drivers side ) 170F. Should there be that much difference between actual fluid reading and the pan sheetmetal temp? Have not done the flow test but am wondering if the guage or sender is shot. If so what is the best way to trouble shoot this? Thanks.
