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FORD DPS6 TRANSMISSION PROBLEMS

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Stop ad go is all about the converter, lots of heat!

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Every car has it's own range of where the temperatures for the engine coolant/cylinder head, and transmission fluid, sort of "settle".  For whatever reason, each car is somewhat unique, and it's hard to even compare 2 cars of the same model with similar equipment.   Drive any car long enough, and you will notice where that range is.  I see that my Transit Connect coolant temperature  can be as low as 181 at freeway speed, and soars to 210+ on city streets.  The transmission fluid temperature on my car will run from 195 - 210.  These are numbers I look at towards the end of the day, after all day of driving.  Where highway speeds and better airflow lower the coolant temp significantly, the transmission temperature lowers when I'm sitting in PARK.  It makes sense that the transmission fluid increases as I'm driving, and lowers when the car is in PARK.  I haven't seen 225 - 250, which would cause for alarm.

 

In my mind, because I'm old, that little heat exchanger on the Transit Connect appears inadequate.  But in reality, despite my personal bias,  it does work.  I haven't seen any overheating.  I have yet to read reports of overheating from members on this forum.  If the fluid cooler bypass valve closes between 180 - 190 like most Fords, then it is working.  Transmission fluid remains above 180 once the car is warmed up.  The scare is that the bypass valve does not close, and the transmission fluid loops back to the return line, without cooling.  

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On 8/11/2019 at 9:33 AM, mrtn said:

At what temp are your 6F35s running? Mine is 208F at highway speeds.

Here's what mine looks like at idle, 55 mph, and 70 mph.

 

 

IMG_20190904_120158430.jpg

A2F3E3B1A811440C99C26BD73F1444B1.jpg

E83D7A95CC9346E28D5D72DA253D0B4E.jpg

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I've been looking around trying to find factual data on what the temperature range for Mercon LV should be. I wish I could provide that source. Most links take me to forums that post peoples opinions on what that should be. Frustrating.

 

Our TC trans uses a coolant warmer/cooler. Lubrication failures can occur if the fluid is too cold or too hot, so this makes sense. Most modern day engine coolant thermostats open about 195 degrees,  which can lead one to think that 190 would be the bottom of the temp range and up to about 225 degrees. The temp data in the previous posts seem to qualify that.

 

My auto trans teacher at UTI years ago taught us that 2 things kill auto transmissions, heat and dirt. Keeping the fluid cool and regular fluid changes are the keys to longevity. For most of us, driving in fairly normal conditions, the fluid temperature should stay in this normal range, and draining and refilling the fluid every 30K is a good idea. If you carry heavy loads or tow consistently, a extra cooler may be required. B&M makes a cooler series that includes a bypass valve when the fluid is too cold. How to tap into the factory cooling system is another issue all together. It's not as easy as it used to be. Your driving conditions will vary and make your own decisions on whether a cooler is necessary. I like the idea, but not sure if it's worth the effort.

 

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2 hours ago, zalienz said:

Most modern day engine coolant thermostats open about 195 degrees,  which can lead one to think that 190 would be the bottom of the temp range and up to about 225 degrees.

 

The Transit Connect's ATF flows out to a cooler bypass valve which is open to allow ATF to bypass the cooler and return to the transmission.  When the transmission reaches the correct temperature, the valve closes, which allows the transmission fluid to flow to the oil-to-water heat exchanger.  We know that OEM thermostats are set to open at 195F.  I have read that the Ford cooler bypass valve closes at 185F.  Derale has a similar aftermarket valve which closes at 180F.  This feature prevents overcooling the transmission, as ATF will not begin to cool effectively until the valve closes. 

 

At the heat exchanger, coolant comes from the overflow tank, then flows to the lower radiator hose and heater core.  At the connections, there are electrically controlled valves, which are opened and closed by signal from the car's computer.  If the ATF temperature read by the computer is at the correct temperature, the valves open, allowing for coolant to carry heat away from the heat exchanger. 

 

A more complex system to regulate and maintain transmission temperature than the old days where there was just an open loop of ATF flow through the cooling and return lines.  

 

3 hours ago, zalienz said:

If you carry heavy loads or tow consistently, a extra cooler may be required.

 

3 hours ago, zalienz said:

Your driving conditions will vary and make your own decisions on whether a cooler is necessary.

 

I agree.  If the transmission is operating between 225F - 250F, it's time to address auxiliary cooling.  Also time to consider why the temperature is high. 

 

Going uphill causes temperatures to climb.  Not much you can do, except to choose a different route.  Some don't have that option.

 

If you are overloading the transmission, you may want to consider that you are carrying and/or towing too much weight.  Obviously, we all can't tow & haul with a larger truck, as a lot of people do not have the option.  For some, this is the only vehicle that they have, so there really isn't a bigger truck available. 

 

The possibility exist that you have other faults, like a transmission pump which isn't performing at optimal efficiency, or a failure within the cooling system.  The cooler bypass valve may be stuck open.  The electrically controlled coolant valves may have failed.  The cooling line, return line, and/or the heat exchanger may be clogged.  

 

The real problem is that the transmission is working harder than designed, you add extra cooling to lower the temperature, which helps with maintaining the longevity of the fluid, but the transmission is still overworked.  So even with extra cooling, the extra wear on the transmission will decrease the longevity of the transmission. 

 

We have not, as yet, seen on this forum where any forum members are reporting temperatures up to 250F.  My suspicion is that if the Transit Connect is not overloaded, the OEM cooling system is sufficient.  In most cases, an auxiliary cooler is not needed.

 

3 hours ago, zalienz said:

How to tap into the factory cooling system is another issue all together. It's not as easy as it used to be.

 

It's not any easier, or harder, than other cars.  The cooler would be inline after the heat exchanger, and before the cooler bypass valve.  Same theory.  Extra cooling after the OEM heat exchanger, in case the fluid is so high in temperature that the heat exchanger is not sufficient.  

 

The Transit Connect return lines are metal tubes. Cut the metal tube.   Add plumbing to auxiliary cooler.  You or your transmission shop will decide whether to install transmission hose, or fabricate a system of custom bent pipes.  Use appropriate fittings at the connection points.  The easiest route is to cut the metal tube, flare it, slip on transmission hoses, and use hose clamps.  Find suitable location for cooler, and choose a cooler with correct dimensions to fit.  Not any easier or harder than it used to be.  Same process as it used to be.

 

At his point, I just don't see the need to add extra cooling.  It appears as if the OEM cooling system is working as designed.  Forum members are not reporting ATF temperatures in excess of 225F.  Sure, somewhere along the way, someone will see an occasional spike, but it hasn't been reported here yet.  The occasional high temperature really isn't a big deal.  As long as the cooling system brings the temperature back down.  The real concern is consistently operating at high temperatures.  If someone reports that every day, the transmission temperature goes up to 250F, and stays in that range all day as they drive around for hours, then there is a concern.

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On 9/19/2019 at 7:14 PM, zalienz said:

Lubrication failures can occur if the fluid is too cold or too hot, so this makes sense.

 

 

Overcooling occurs in extreme cold weather. Subzero ambient temperature.  Transmission fluid can actually gel up in the lines and in the cooler.  The Transit Connect is engineered to avoid this issue by returning transmission fluid via the bypass valve.  A little bit of misplaced concern.  In a subzero climate, you will not drive a Transit Connect.  

 

A bigger concern would be extremely hot ambient temperature.  100F + conditions in the dessert.  

 

I don't know of any Transit Connects in Alaska, or Saudi Arabia.  In North East snow states, overcooling has not been a problem.  Or at least not that I have read.  Have there been overheating issues in South West dessert environments?  

 

Some of us, who have been around awhile, are referencing our decade(s) of experience.  Old tech training and information, applied to modern technology.  We go back to the charts which showed us 175F as an optimal transmission temperature. 

 

Back in the old days, temp gauges were installed with a sensor in the pan.  Cool fluid returning is dumped into the pan.  Or if you followed the instructions, the temperature sensor was suppose to be in the return line between the coolers and transmission, to gauge the effectiveness of the cooling system. 

 

Modern sensors in the valve body, being read electronically by the car's computer, are reading a higher temperature.  The sensor is located where the fluid is hotter.  People who have mechanical gauges in the pan, and ScanGauge have reported 10 - 15 degrees difference in temperature readings, with the pan sensor reading cooler than the scantool temperature from the valve body.  Transmission builders also say that temperature is highest in the torque converter, so a sensor in the cooling line as fluid exits will be a higher reading.  

 

Modern transmissions are designed for operation at higher than 175F.  Even the transmission fluid, just like modern engine oil, is a different formulation.  May as well go back to changing oil every 3,000 miles.  Or hanging fuzzy dice on the mirror.

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34 minutes ago, Double Nickels said:

I don't know of any Transit Connects in Alaska, or Saudi Arabia.  In North East snow states, overcooling has not been a problem.  Or at least not that I have read.  Have there been overheating issues in South West dessert environments?.

 

Our temps drop to -30F for a couple of weeks usually in Jan-Feb. I have not noticed any behavioral difference by the transmission.

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6 hours ago, mrtn said:

Our temps drop to -30F for a couple of weeks usually in Jan-Feb

Mine also.  The only change I make is to allow a warm up to make sure all the brittle plastic parts on both the engine and Transmission are happy.

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Yup, I've now switched to 5W-30 at 50K.

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Yup, I've now switched to 5W-30 at 50K.

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I am using a 5w-20 full synthetic at the moment but could go to 5w-30.  The synthetic stays fluid at the low temp.  The thin oil is for the fuel mileage ratings.

You might need it if it went to -40 or lower.  At -40 I have another plan Stay home by the fire!! 

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Makes sense. I wouldn't want to drive a Transit Connect in that weather. Roads are probably covered in ice and snow.  

 

Apparently @ -30 degrees, your Transit Connect vans are still gripping the pavement.  Is this with stock tires?

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No way, dedicated severe snow service tires are mandatory over here from 1st of Dec to 31st of March.

kw31.jpg

Edited by mrtn

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They are not mandatory  here but if you don't have good tires we do not have to feel bad passing you in the ditch!

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On 9/21/2019 at 12:35 AM, Double Nickels said:

Have there been overheating issues in South West dessert environments?  

 

 

Not Las Vegas or Saudi Arabia.  Portola Valley hit 102 F today.  The President left last week.  He didn't take me with him.  I am still here, and it was hot.  Transit Connect did not overheat.  You can see by the high RPM that I am going uphill at freeway speed.  My regular route goes up very steep grades at high speed and high RPM.

 

 

Screenshot_20190924-150911.png

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There's some pretty great readings for 102 degrees

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With my driving style, I see the same range of temperatures whether the ambient temperature is 51 or 102.  That's just me.  It's different for everyone.  If I had another 1,000 lbs of cargo or people, if I was at a different elevation, if the humidity was different.........who knows.  In The Bay Area, we are close to sea level.  I travel up and down The State, and my temps look the same after driving all day.   I haven't seen any overheating yet.  This is a fairly efficient cooling system. 

Edited by Fifty150

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22 hours ago, zalienz said:

There's some pretty great readings for 102 degrees

104 today.  Similar temperature range. Heats up a little in stop and go.   Airflow from driving 30 mph or more, brings the temps down.

 

PSX_20190925_164657.jpg

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Ambient air in the 70s, and temperature range is consistent.  It seems like the fan turns on when coolant reaches 212F, or 100C.  With my driving, movement and airflow reduces coolant temperature.  

 

 

PSX_20190926_162726.jpg

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Stop and go, The converter is unlocked and that means more heat.

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And after all day of driving in stop and go, on hills, my temperatures are still in the same range.  On my van, with my drive style, fluid temperatures maintain consistently whether the ambient air is in the 50s, or over 100.

 

 

PSX_20190927_194751.jpg

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