Jump to content
Sign in to follow this  
macbwt

Transmission Fluid thermal bypass valve failure

Recommended Posts

Transmission Fluid thermal bypass valve failure. Have a few quires. Does anyone have information on the temperature at which the bypass valve opens?

 

Anyone else have a documented failure? I have found some information. Not much on net and nothing on YT. I am getting prepared to replace this part as my transmission is overheating gradually during long 150+ drives.

 

No warning lights at is does not reach the point of overheating to send a Wrench light or CEL

 

Any information on this would be appreciated or links to additional information.

 

 

Share this post


Link to post
Share on other sites

Don't have a DEFINITE answer to the opening temp, but the FSM does say this:

When the transmission fluid is at or above normal operating temperature, the transmission fluid thermal bypass valve opens allowing transmission fluid to travel from the transaxle through the transmission fluid cooler then back to the transaxle.

And the manual specs NOT as 180-200F

The transmission fluid should be checked at normal operating temperature 180°F-200°F (82°C-93°C) on a level surface.

 

So I'd say around 180F.

Share this post


Link to post
Share on other sites

I read somewhere that the fluid by pass opens at possibly 85 degrees F for reason to allow the quickest heat up time for the overdrive in the transmission. The interesting thing is the trans temp as you posted says 180-200 degrees F So based on that I am not completely out of spec but still running at this time after fluid replacement about 200 consistent at highway speed over long drives. In town however today it start to go up to 201 and 202 but would also drop. So maybe my trans is not running too hot with the new fluid, but it was running 210 on the highway at speed and that is over the spec.

 

Still in the maybe category on if a new bypass valve will be the cure to keep the temps down. I may just pull the trigger and replace it anyway.

  • Like 1

Share this post


Link to post
Share on other sites

Mac, are both your Edges the same with regards to the towing package? (both have it/don't have it). I think this might be a major difference that could affect temp difference between both.

 

Also, as per the Owners Manual, it is normal for the trans tempreture to increase after long drives:

 

Automatic transmission fluid expands when warmed. To obtain an

accurate fluid check, drive the vehicle until it is warmed up

(approximately 20 miles [30 km]). If your vehicle has been

operated for an extended period at high speeds, in city traffic

during hot weather or pulling a trailer, the vehicle should be

turned off until normal operating temperatures are reached to

allow the fluid to cool before checking. Depending on vehicle use,

cooling times could take up to 30 minutes or longer.

  • Like 1

Share this post


Link to post
Share on other sites

A somewhat more modern setup in the Ram 1500

http://articles.sae.org/11310/

 

Ford's using all that stuff (and more) on the newer models too.

Edited by Waldo
  • Like 1

Share this post


Link to post
Share on other sites

Neither Edge is set up for towing and do not have a towing package.

  • Like 1

Share this post


Link to post
Share on other sites

I am waiting for transmission fluid testing results. After the test is received I will evaluate my next step. In the mean time I will be cleaning the condenser to ensure it is not dirty. I pick up the new bypass valve today and will wait for the test results. I still may replace it. The replacement may end up one of two ways. Either it helps reduce the temps or it does nothing to change it. 45 bucks to find out.

 

Still trying to figure out why to exactly the same Edges have two different temps on the transmission. Curious.

  • Like 1

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×