5R55E ATF temperature?

[2000StreetRod]

I've read that the 5R55E transmission has internal thermostatic control of the ATF temperature. When the ATF temperature exceeds a certain value the external flow to coolers is enabled. I have a remote ATF filter and two stock coolers. I bypassed the radiator mounted cooler. My remote filter never gets warm to the touch and my temperature sensor at the inlet to the filter (output of the transmission) never exceeds the minimum of my pod mounted gauge (100 degrees F). However, my data log during a WOT test recorded a max internal ATF temperature of 177 degrees F when the outside air temperature was 32 degrees F.

Has anyone monitored the PCM "transmission temperature" parameter with their scanner? If so, what temperature ranges did you observe?

 

[2000StreetRod]

Any help?

Does anyone have any 5R55E automatic transmission temperatures they have read using a scanner?

 

[2000StreetRod]

External loop temp

Does anyone know at what temperature the 5R55E opens the external cooler path?

 

[Ronin8002]

Not sure if this is much help as I have the 5r55s but during normal driving I see temps of 160-170 most of the time, regardless of outside temperature. A few times on some long steep climbs with the OD off it got up to 188.

Based on the temps I suspect the external fluid path on mine opens around 160.

 

[2000StreetRod]

Thanks for response!

Not sure if this is much help as I have the 5r55s but during normal driving I see temps of 160-170 most of the time, regardless of outside temperature. A few times on some long steep climbs with the OD off it got up to 188.

Based on the temps I suspect the external fluid path on mine opens around 160.

Thanks so much for your response! That temperature range is about what I would expect. My ATF does not flow thru the radiator oil cooler as in the stock configuration. My engine oil flows thru an added external cooler and then thru the radiator cooler. I have a duplicate stock ATF cooler in parallel with the original.

 

[2000StreetRod]

Suspicions confirmed

This morning I performed my first warm weather data log of my transmission temperature. As I suspected, the data log confirms that I definitely have a transmission fluid cooling problem. The transmission temperature was 76 degrees F at engine start. The temperature almost continuously increased for the entire duration of my 51 minute drive. At engine shut down the transmission temperature was an excessive 244 degrees.

My ATF coolant flow is rather unique and is as follows:

Transmission outlet port > remote spin on oil filter mount > "T" fitting splitting flow > 2 stock external oil coolers in parallel > "T" fitting combining flow > transmission inlet port

I began to suspect I had an ATF coolant flow problem when I noticed that my spin on oil filter was not warm to the touch even after a 30 minute drive.

There are several possible causes for my ATF overheating:

1. The remote oil filter mount is connected to the transmission inlet port instead of the outlet port and the spin on filter check valve is preventing reverse flow. I assumed that the top port on the 5R55E is the outlet port.

2. The inexpensive spin on oil filter is defective and preventing flow.

3. The pressure of the ATF at the transmission outlet port is too low to overcome the resistance of the filter and coolers.

4. The 5R55E external flow control valve is defective.

5. The 5R55E temperature sensor that controls the external flow control valve is defective.

I think the first thing I'll try is to bypass the oil filter and perform another data log.

 

[BrooklynBay]

Some external oil filters have a built in temperature contolled valve that conflicts with the temperature control which is built into the 5R55E valve body. I've seen some members report similar issues when they used similar thermostatic filter housings. You have to use a non thermostatic filter housing.

 

[2000StreetRod]

Thermostatic filter housing

Some external oil filters have a built in temperature contolled valve that conflicts with the temperature control which is built into the 5R55E valve body. I've seen some members report similar issues when they used similar thermostatic filter housings. You have to use a non thermostatic filter housing.

Thanks for the idea but in this case I doubt it applies. My mount is one of the inexpensive Permal-Cool remote oil filter brackets like the one shown below. It's nothing more than a piece of cast aluminum.

 

[2000StreetRod]

External flow starts at 150 degrees

I finally found an article named Troubleshooting tips for the 4R44E and the 5R55E that states ". . . converter fluid must reach 150 degrees Fahrenheit before the thermal element opens, allowing for external cooler flow."

Here's a link to the article that contains a lot of useful information: http://www.sonnax.com/tech-articles/TS6-BW-106-109.pdf

 

[BrooklynBay]

Maybe your internal thermostatic control in the valve body is malfunctioning? You could bypass it. Check the sticky thread on the top of this section from INH: http://www.explorerforum.com/forums/showthread.php?t=249659

 

[2000StreetRod]

External ATF flow established

I finally have ATF flow thru my remote filter and coolers and my pillar pod mounted transmission temperature gauge is displaying reasonable readings. I decided to change the most uncertain and easily modified possible problem source - the direction of ATF flow to the remote filter. Apparently I erroneously connected the remote oil filter inlet port to the transmission external cooler inlet port instead of the outlet port. As a result, the remote oil filter back flow preventer was preventing the flow of ATF when the transmission external loop control valve opened.

After swapping oil paths I made a short round trip to the local cleaners to pick up my suit. Upon leaving the house the remote oil filter inlet temperature was about 100 degrees. It gradually increased throughout the short trip and was 140 degrees upon returning home. Previously, the gauge reading had never moved after the ignition was switched on.

The next step is to go for another test drive data logging the transmission temperature on the OBD bus and compare it to the pod gauge reading. Hopefully, I'll be able to confirm that the external flow control valve opens at 150 degrees and that my two external coolers have adequate capacity without using the radiator internal cooler.

 

[BrooklynBay]

Thanks for the update! These oil filters contain a check valve.

 

[2000StreetRod]

ATF cooler goals met!

I did another data log this morning with the rerouted ATF oil flow. Intake air temperature (IAT) at cold start was 68 degrees F, scanner transmission temp was 70 degrees F and ATF temp at inlet to remote oil filter was below the gauge minimum reading of 100 degrees F. The scanner transmission temp continued to increase steadily for the first 19 minutes and then leveled at 145 degrees. On the previous drive the scanner temp at 19 minutes was degrees. In the 30 minutes of today's drive the scanner temp never exceeded 158 degrees and the gauge reading of the ATF temp was 160 degrees. It appears that two of the stock auxiliary oil coolers without the radiator internal oil cooler is adequate for summer operation. Since the 5R55E has internal thermostatic control of the external cooling loop the radiator internal cooler is not needed for winter heating of the ATF.

I also monitored the operation of my engine oil coolers. The scanner engine coolant temperature before engine cold start was 74 degrees F which was reasonable. However, the pod gauge reading of the oil at the remote filter inlet was 150 degrees which seems unreasonable. Immediately after engine start the pod gauge reading increased to 193 degrees and after 30 minutes of driving registered 185 degrees. The scanner showed the thermostat opened at 196 degrees after 7 minutes of driving and the engine coolant temp fluctuated between a max of 202 and a min of 195 for the rest of the drive. The sensor for the engine oil is identical to the sensor for the ATF. According to the pod gauge the temperature of the Accusump oil was 40 degrees warmer than the engine coolant temperature. I will have to investigate further to explain the unusual readings.

 

[2000StreetRod]

Lower 5R55E port is outlet for external cooling

I traced my functional remote ATF filter inlet port back to the transmission to find out for sure which port is the outlet port for the external cooling loop. It is the lower port. There are several reasons for the confusion as to which is actually the outlet port. One reason is that there are bends in the rigid lines to allow for length adjustment. The bends on my Sport result in the upper port being the lower line and the lower port being the upper line to the coolers. Another reason is when both lines are disconnected at one of the coolers and the engine is started, ATF will flow out of both lines. If the transmission is cold then more ATF will flow out of the upper port than the lower port. I performed this test and erroneously assumed that the port outputting the most flow was the outlet port.