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Caliber 2007 Dodge Caliber cvt, where is the cooler? and can I add another one?

Discussion in 'Compacts: Renegade, Patriot, Compass, Caliber' started by Ammon, Aug 14, 2015.

  1. Ammon

    Ammon New Member

    My Caliber transmission overheats when I'm going above 65 miles per hour, but is fine when I slow down. I had the oil changed about 20 thousand miles ago and it does not smell or look burnt. I took the front bumper off and found the can shaped transmission cooler on the side of the transmission, which I do not understand. It has a pair of coolant hoses that go to the radiator hoses and a pair of hoses that go to the left side of the AC condenser. Are those hoses full of transmission fluid? If so, can I mount an air to oil cooler in one of those lines? If not, is there transmission oil lines that I can tap into to add and air to oil cooler?
    Any other ideas or better ways to keep this transmission from overheating?
  2. ImperialCrown

    ImperialCrown Moderator Level III Supporter

    The 'can' is an oil-to-coolant heat exchanger to help regulate transaxle fluid (Mopar CVTF+4 only) temperature. It will tend to help warm the fluid in cold winter driving and help cool it in summer under high load conditions.
    The hoses to the A/C condenser use a few rows of the condenser tubing to act as an air-to-oil cooler. Unless something is very wrong, you shouldn't really need extra ATF cooling.
    Does the transaxle temperature sensor reading seem accurate when driving with a scan tool from cold to warm?
    Since it happens in highway driving, you should have good airflow through the A/C condenser and radiator. If the torque converter clutch (TCC) isn't locking up or slipping, that would increase fluid temperature in highway driving.
    Do you feel the converter locking up? It should happen after the temp gauge reaches 1/3 of the way up at road speeds over 40 mph. You may notice TCC action by reading the tach. Just starting out with a cold engine, does the tach read ~2200 rpm at 55 mph and after the car warms up read ~2000 rpm at 55 mph? That 200 rpm speed drop would be the difference between a non-locked and a locked TCC.
    Is your only TCM fault code for ATF over-temperature and not for any TCC fault?
  3. Ammon

    Ammon New Member

    Thank you for the info! Now looking at the AC condenser I can see that the top part is the transmission cooler. I drove it and could not get it up to speed before it got up to temperature on the freeway, and frankly cannot tell when the torque converter locks up because the rpms are always floating around a little bit as I am getting up to speed, but on the flat at 55mph it is right at 2000 rpm and going up a 4 or 5% grade it goes to 2200 rpm and going down that same grade is about 1800 rpm. I felt the two tubes going to the transmission cooler and they are hot, but not too hot to touch for a moment, so fluid is getting there. The car has 126k miles and the PO said he had the transmission fluid changed maybe 20k or 30k miles ago. As I said above, the fluid looks fine, but I cant think of anything else but change the fluid.
    Regarding other faults, when it overheats, the light goes on, then it goes off when it cools off. Chrysler wants 100+ bucks to read fault codes, so I haven't done that, but when I check with my OBD reader, there are no stored faults. Any other ideas?
  4. ImperialCrown

    ImperialCrown Moderator Level III Supporter

    You would want to compare the RPM at 55 mph while the temp gauge was still at 'C' with the RPM at 55 mph with the temp gauge at a normal halfway reading and not the difference in RPM. Try not to be climbing a hill or accelerating during this comparison.
    The torque converter doesn't lock when it's still cold, but should
    lock up when warm.
    The cooler does sound like fluid is circulating, but a cooler restriction could cause overheating. Then the question would be, why is it restricted and with what? Clutch material from wear?
    I think another CVTF+4 fluid/filter change would be a waste of time and money and you will still have the overheating issue.
    The $100 diagnostic fee is about 1 hr labor and is the normal charge. The diagnostic fee gets applied to the repair if you decide to get it fixed.
    If the transaxle is damaged internally, CVT replacement as a unit is the only service. This would be the worst case scenario.
    Chapter 21 is the transaxle chapter if you want to look up diagnostics and fault codes that they may find. There may be no fault codes if the transaxle is actually overheating. Large 131 mb file: Manuals/2007_PM_Caliber/2007-PM-SM.pdf
  5. Ammon

    Ammon New Member

    I took it out again and was able to get to speed before the temp gauge went up. The rpm were as predicted signaling the torque converter is working correctly.
    Any other suggestions? I appreciate your efforts.
  6. ImperialCrown

    ImperialCrown Moderator Level III Supporter

    I am glad to hear that the converter seems to be locking up OK. Slipping generates heat and I am still thinking that a clutch may be slipping and causing the overheat if this only happens with highway driving over 65 mph. Nothing is blocking the radiator air flow, correct?
    Are there any stored fault codes associated with the transaxle overheat warning light?
    See p. 21-106 of the service manual for the CVT 'P' code list.
    There are 3 possible CVT temperature-related fault codes; P0711, P0712 or P0713. Are any of these codes present?
    If so, go on to the diagnosis page of the fault code.
    If not, then the fluid overheat warning is probably real.
    I don't know your diagnostic or repair skills. You have to narrow down the possibilities. This may require you to consider a trip to the dealer for more advanced diagnostics and an answer to the overheating fluid.
    If they can road test it over 65 mph with a scan tool to watch the fluid temperature and clutch input/output speeds, they should be able to tell what is happening. Then you can decide the best course of action.
    Worst Case Scenario: Is the condition of the rest of the car good enough where you would consider replacing the CVT assembly if you had to?
  7. Cornupenuria

    Cornupenuria Member

    Is the lower third of the AC condenser coil in front of the radiator free of bugs and dirt?
    ImperialCrown likes this.
  8. chuzz

    chuzz Active Member

    What color is that fluid and how are you checking it? My 2008 Caliber didn't come with a transmission dipstick. It just had a plug in the tube and was supposed to be checked at the 100,000 mile interval. Mine never made it that far.
  9. ImperialCrown

    ImperialCrown Moderator Level III Supporter

    CVTF+4 should be green when fresh. It may go tan with age. It is more expensive than conventional ATF+4 and may be fully synthetic. Use no other fluid type.
    Mine had no burnt odor, but the fluid has a strong odor normally.
    None have a dipstick. My fluid was 2 1/2" at ambient temperature after sitting overnight on level ground. Use a piece of speedometer cable (or equivalent) to check the level.
    It took 6 quarts to fill. There are 2 chip magnets at the bottom of the pan. Both had a light haze of dust.
    Overall the fluid and filter were in good shape at 30K miles, but I changed it anyways for break-in fluid maintenance and peace of mind.
    P.S.- There is a 2nd filter behind the fluid cooler. It is shown in the service manual, but is not listed in the Mopar parts catalog. Mopar does not service this filter. This may be the problem? It is available generically aftermarket as FK-403:
  10. CVT4me

    CVT4me Member