High Transmission Temperature

[fbov]

Well, it may not be related, but I'm seeing a new cold-engine run mode, sort of an EV-. After a cold boot, when engine has just started, I don't see any torque coming out of the ICE, it's all EV. This continues for about 30 seconds, the time to my first turn, then EV shuts down and it's normal ICE-only until the engine warms a bit.

 

I call it "EV minus" because it's very similar to EV+ in that you have access to a full 2-bars of EV thrust, and Engage tells me It's all blue bar; the ICE is doing none of it. .

 

What I wonder, is if this slight change to power flow during warm-up might reduce wear on a certain transmission bearing? No idea how long this has been happening, but I only noticed since things warmed up, and I have had recalls done this Spring, too.

 

HAve fun,

Frank

[ptjones]

If we are talking about the same thing, I call it the Cold Start Condition depending on your SOC. If your HVB SOC is lower than 38% the ICE is going to start immediately although it will run down SOC to 33% before starting to recharge it.  This morning this happened and ICE ran for .2mi. then went into EV after letting off the gas pedal and on the brakes for stop sign. WT was about 100*F, normally it won't go into EV until WT is 128*F.  

 

When SOC is above 40% ICE won't start unless you push pretty hard on accelerator and ICE will continue to get an assist until HVB is down to around 33%.  I believe this happens when HVB is cool when you first start the car.

 

One time I started out with 70% SOC and the car acted like an Energy up to 35mpg when ICE automatically came on, but EV kept going until HVB SOC dropped to 38%.  I believe this is done because cold ICE is more efficient above 25mph, so the faster the speed in EV, the more efficient the ICE will be when it turns on. :) 

 

Paul 

[hybridbear]

Well, it may not be related, but I'm seeing a new cold-engine run mode, sort of an EV-. After a cold boot, when engine has just started, I don't see any torque coming out of the ICE, it's all EV. This continues for about 30 seconds, the time to my first turn, then EV shuts down and it's normal ICE-only until the engine warms a bit.

 

I call it "EV minus" because it's very similar to EV+ in that you have access to a full 2-bars of EV thrust, and Engage tells me It's all blue bar; the ICE is doing none of it. .

 

What I wonder, is if this slight change to power flow during warm-up might reduce wear on a certain transmission bearing? No idea how long this has been happening, but I only noticed since things warmed up, and I have had recalls done this Spring, too.

 

HAve fun,

Frank

 

 

If we are talking about the same thing, I call it the Cold Start Condition depending on your SOC. If your HVB SOC is lower than 38% the ICE is going to start immediately although it will run down SOC to 33% before starting to recharge it.  This morning this happened and ICE ran for .2mi. then went into EV after letting off the gas pedal and on the brakes for stop sign. WT was about 100*F, normally it won't go into EV until WT is 128*F.  

 

When SOC is above 40% ICE won't start unless you push pretty hard on accelerator and ICE will continue to get an assist until HVB is down to around 33%.  I believe this happens when HVB is cool when you first start the car.

 

One time I started out with 70% SOC and the car acted like an Energy up to 35mpg when ICE automatically came on, but EV kept going until HVB SOC dropped to 38%.  I believe this is done because cold ICE is more efficient above 25mph, so the faster the speed in EV, the more efficient the ICE will be when it turns on. :)

 

Paul 

This sounds like S0 of the warm up stages. I'm not sure exactly where that is posted here but I'm pretty sure it is.

[SnowStorm]

I have noticed the EV- mode (continue running on HVB for a short time after ICE starts) for quite a while.  When I first noticed it I thought something was wrong.  It seems like a great way to start an ICE & extend its life - keep torque low until everything is well lubricated.

[ptjones]

I'm thinking about getting a 12v fan to blow air around Trans to cool it. It would be nice if I could find a temperature switch for around 160*F to make it automatic.  I'm going to get Digital Thermometer to monitor cooler line temps too.

The perfect plan is to have ICE running between 202-212*F and Trans around 150*F for the best MPG.  :)

 

Paul

[ptjones]

I checked again with SM at Dealer and he said there are no specs for temp range for HF35 CVT Trans.  On TrueDelta.com they have 3 failed Trans for CMAX's, mine and two low mileage CMAX's.

Paul 

[SnowStorm]

So is there any way to tell when the "fix" was implemented?  There's only 34k miles left on my warranty - I don't want to replace a transmission on the way to 250k miles!

 

Paul, did your paperwork break out labor cost versus parts?

[ptjones]

TrueDelta didn't have any FFH or Energi's listed. There is a CMAX NRG owner with 70Kmi that got new trans.  Right now we have virtually no info from FORD other than if it makes noise replace it. No preventative maintenance like changing the Trans Fluid at 50Kmi.  All the info I have come up with is the normal temp range for Hybrid is around 150*F and mine got up to 199*F before I first  heard the high pitch sound from Trans. When Trans was removed Trans Fluid was darker than normal and smelled burn, but no metal filings.  My new Trans has already gotten to 192*F with 1600mi on it. Generally speaking high TFT are caused from FWY speeds and not around town.  I will come up a band-aid solution eventually, but first I need to do more testing.

 

Paul  

Edited May 28, 2015 by ptjones

[ptjones]

So is there any way to tell when the "fix" was implemented?  There's only 34k miles left on my warranty - I don't want to replace a transmission on the way to 250k miles!

 

Paul, did your paperwork break out labor cost versus parts?

They didn't put any cost numbers(Warranty), just parts break down and no labor.  It might be a good Idea to extend your warranty when you get close. ;)

 

Paul

[ptjones]

The question has been asked whether MAX speed/improved MPG for HWY Software update effected TFT.

 

The Software speed change (62 to 85mph) didn't effect TFT, the change in shutter opening did, before it would start at 190*F and fully open at 213*F, now it  waits to open till 215*F.  I made a trip 25 miles up and then back, I was only able to get WT up to 207*F on the way up with Grill Covers on OT 80's, but TFT got to 175*F.  Before returning I removed tape from 5x2" holes in the lower grill cover and then returned home down the I-85. the ICE had cooled down some so I had to run the ICE  most of the time to get to 215*F for the shutters to open, by that time TFT was up to 179*F, but then dropped down to 175*F in ten miles with ICE running most of the time. The only time Trans Fluid gets circulated is when ICE is running the Trans Pump. The WT stayed in the 215-225*F so the shutters were open most of the time. My speed was 65-75mph  and I averaged 52mpg for the trip. 

 

BTW I don't recommend a Trans Heater Pad, because of the loss of cooling surface area. ;)

 

Paul

[ptjones]

It is worth mentioning if you think you are having Trans issue find a Dealer that has replaced one.  Hopefully they will know what they are doing and won't be learning at your expense. IMO ;) 

 

Paul  

[Sparky]

My C-Max, built March 2013, has been diagnosed with a failing transmission.  I am now waiting for a new one to be delivered next Monday.  The Energi has 44,000 miles.

The Ford mechanic diagnosed the problem by driving around the lot.  The sound, in my experience, is that of a failing roller or ball bearing.  The sound is similar to a bad axle bearing. I have never checked the trans. temperature.

I live in the Sierra foothills at 2,000 feet elevation, near I-80.  A typical day for the car starts by driving a mile at 30 mph to the freeway, then down hill to Sacramento at 65-70 mph.  The first 25 miles are with the ICE off, never starting.  I can go 25 miles because it is mostly down hill.  Sacramento is about sea level.  The engine remains cold.    In the winter mornings are at or below freezing.  

I believe my failure was caused by lack of lubrication due to low temperature ATF.  

I do not understand the purpose of the fluid pump used on the Energi.  Is it to provide oil delivery to the gears and bearings, or to provide flow thru the ATF cooling radiator?  

What has been done to the later transmissions to fix the problem?

After my repairs are complete, I will replace the fluid with full syntetic ATF.  I hope it will provide better lubrication at both high and low extremes of temperature.

Edited June 4, 2015 by Sparky

[ptjones]

I didn't know they made CMAX's in 1913 LOL.  It's to bad you weren't able to check your Trans temps, It would have been a good data point.

 

I'm assuming Trans Fluid is being pumped through the cooler to the bearings in the Trans and then to the gears.

 

It wouldn't hurt to open up hood every time you stop during hot temps to allow the Trans to cool off some, otherwise it won't.

 

IMO this whole Trans failing problem could be caused by high TFT or Bad Bearings or the combination of both. It does look like people who do a  lot of FWY driving are having the bulk of the problems, maybe all.

 

I like the idea of using synthetic AFT, it couldn't hurt.  I don't know that FORD has done anything to solve the Trans problem, only time will tell. ;)

 

Paul

[SnowStorm]

I didn't know they made CMAX's in 1913 LOL.

Maybe not C-Maxes but there were hybrids long before then!  And no transmission problems either!  (But I won't comment on the unsprung weight!)

[hybridbear]

I do not understand the purpose of the fluid pump used on the Energi.  Is it to provide oil delivery to the gears and bearings, or to provide flow thru the ATF cooling radiator? 

I believe the fluid pump serves to circulate fluid through the radiator to cool the TFT. The eCVT should circulate the fluid as the gears turn.

[ptjones]

In case someone may have missed this the Trans has it's own cooler in front of the ICE radiator, they are separate. :) 

 

Paul 

[ptjones]

Here is a Link to a site on Trans temps and longevity:  http://www.txchange.com/heatchrt.htm.  Ideally you want it to below 175*F. :)

 

Paul

[SPL Tech]

 Do the "right thing" Ford as you have done in the past.

Are you kidding me? Have you ever bothered to look into Ford's history? There is a movie about it. Here's the trailer. It's based on a true story.

 

 

Ford even outright defrauded consumers on their fraudulent EPA estimates using the same-frame model exception authorized by the EPA to get their bogus 47/47/47 EPA estimates. They knew what they were doing, and they knew they were playing the system to try to get consumers to believe the vehicle uses less fuel than it does.

 

Dont hold your breath that any major corporation is going to do anything to help you. Companies exist to make money. They dont do that by offering warranties on parts with engineering flaws.

 

I like my CMAX and I dont have any specific problem with Ford's products, but to trust that ANY (not just Ford) multinational corporation is going to "do the right thing" is naive. These corporations are at the level they are at specifically because they do not do the right thing--they do the profitable thing.

Edited June 22, 2015 by SPL Tech

[ptjones]

 

If there is a significant problem it is in FORD best interest money wise to fix the problem.  Recalls are very expensive.

 

Yesterday I drove 70mi. up the FWY in 90-95*F OT going 60-80mph and TFT got to 190*F, coming back in the evening 85*F OT, TFT got to 180*F. Outside temps do effect TFT  a lot. 

 

I currently have top grill open, center grill blocked off and lower grill blocked off except 5 x 1.5" holes in the cover, it takes approx. 20+min. to get WT to 215*F. then I'm able to keep WT in the 215-225*F range most of the time.  This keeps the shutters open and allowing cooler air  to go through the Trans Cooler there by lowering the TFT.  :)

Paul

Edited June 22, 2015 by ptjones

[obob]

 

 

If there is a significant problem it is in FORD best interest money wise to fix the problem.  Recalls are very expensive.

 

Yesterday I drove 70mi. up the FWY in 90-95*F OT going 60-80mph and TFT got to 190*F, coming back in the evening 85*F OT, TFT got to 180*F. Outside temps do effect TFT  a lot. 

 

I currently have top grill open, center grill blocked off and lower grill blocked off except 5 x 1.5" holes in the cover, it takes approx. 20+min. to get WT to 215*F. then I'm able to keep WT in the 215-225*F range most of the time.  This keeps the shutters open and allowing cooler air  to go through the Trans Cooler there by lowering the TFT.  :)

 

Paul

 

 

So what I think you figured out is that the hot transmission happens when the car thinks it is not warmed up yet.

[ptjones]

So what I think you figured out is that the hot transmission happens when the car thinks it is not warmed up yet.

Actually it would appear that the car  (Computer) doesn't think about the Transmission at all.  So you have to make it work the way you need to make it work.  LOL   It would be nice if you could put Trans and DC to DC converter coolers in front of the shutters so they are getting cooler air all the time this time of year. :)

 

Paul

[obob]

Actually it would appear that the car  (Computer) doesn't think about the Transmission at all.  So you have to make it work the way you need to make it work.  LOL   It would be nice if you could put Trans and DC to DC converter coolers in front of the shutters so they are getting cooler air all the time this time of year. :)

 

Paul

 

I think you may be on to a million dollar idea.  Fixing transmissions and the pissed off owners whose transmissions fail that Ford won't fix cost a lot of  money.

Edited June 22, 2015 by obob

[ptjones]

I think you may be on to a million dollar idea.  Fixing transmissions and the pissed off owners whose transmissions fail that Ford won't fix cost a lot of  money.

You Think? LOL   I have another one,  don't drive faster than 55mph, problem solved. LOL  I'm in the process of connecting shutters to Grill Cover so when shutters open so does Grill Cover.  Add to that a 6" 12v fan blowing air on to Trans I might be able to keep Trans below 170*F. :)

 

Paul

[SnowStorm]

55 mph - back to the "National" speed limit!  Boy, was that a drag.  I drive a lot of 55 mph roads but not all.  But it would help the MPGs!

 

So why not switch to synthetic ATF and forget about temp?

 

Also, should we always force an ICE start first thing to get the tranny lubricated?  Must the ICE run to thoroughly lubricate the transmission or just to pump fluid through the cooler?

 

As to "theories", was the change from 62 to 85 mph EV linked to the improved bearing (or whatever it was)?

[SPL Tech]

Why dont you just change the tranny fluid more often and skip all this taping nonsense? The reason why trannys fail from high temp is not that the trannies are hot, but because the temp breaks down the oil and the oil stops providing lubrication benefits. So change the oil every 50k and the high temp is not an issue.