Welcome To V6Mustang.com!

We are the oldest and largest V6 Mustang forum on the internet. If you have any questions about your V6 Mustang or just want to connect with other V6 Mustang owners around the world, you have found the best place on the internet to do that.

Registering is free and easy! Hope to see you on the forums soon!

Coolant leak 2005 4.0L

Discussion in '2005-2010 V6 Mustang Tech' started by streetstang03, Aug 31, 2009.

  1. streetstang03

    streetstang03 New Member

    Joined:
    Aug 31, 2009
    Messages:
    3
    Likes Received:
    0
    Trophy Points:
    0
    2005 4.0L w/ 65K on the clock. Coolant is leaking pretty heavily when the car is running. When engine is off, no drips at all. When I shut the car off, it stops leaking.

    Is it just a hose, thermostat housing or could the water pump be bad? I jacked the car up and got under it to try and see exactly where the leak is occuring. Couldnt see for sure, but it seems to be around the alternator area. Is this where the thermostat housing is located? I heard the 05 and 06's had a problem with the housing cracking and I'm beginning to think this is the culprit. It was getting dark when I was under the car and started to have trouble seeing things last night. Getting back under after work today.

    Thanks for any advice, suggestions or tips. If anyone has a write up or just some quick steps for replacing the thermostat housing and an engine diagram I'd appreciate it!

    Thanks
     
  2. greensteeda

    greensteeda Retired Speed Racer Mod. Suck It!

    Joined:
    Feb 11, 2005
    Messages:
    19,082
    Likes Received:
    36
    Trophy Points:
    58
    Location:
    Nashville TN
    I'm not too familiar with the new 4.0 motor but there are is a tool you can rent (get all your money back on return) from autozone that will let you pressurize the cooling system to help you pin point the leak. That should get you headed in the right direction.
     
  3. streetstang03

    streetstang03 New Member

    Joined:
    Aug 31, 2009
    Messages:
    3
    Likes Received:
    0
    Trophy Points:
    0
    ya, i'm prob doing that tomorrow. i ran the car tonight to try and pinpoint the leak. seems to be coming out the right side of the water pump but also pooling on the back of the engine block. cant figure out why its pooling back there. its definitely not the thermostat though. im really hoping its not the intake or head gasket. theres no smoke coming out of the exhaust and no coolant or water drops on the dip stick when i check the oil and the color is normal.
     
  4. streetstang03

    streetstang03 New Member

    Joined:
    Aug 31, 2009
    Messages:
    3
    Likes Received:
    0
    Trophy Points:
    0
    FYI: turned out to be the thermostat housing. the lower housing was cracked where it joins the upper.

    If you're having a coolant leak on your 05+ from the housing, you'll see the coolant drip down the right side of the water pump and it will run along the top of the engine (along the intake manifold) and pool up at the back of the block. its hard to see it coming from the lower housing, and you may automatically assume its the water pump.

    cost about $70 in parts to fix. you'll need the upper housing, lower housing, thermostat o-ring gasket and the lower housing o-ring gasket. went ahead and replaced the thermostat as well while i had it apart.
     
  5. JustSpeed7

    JustSpeed7 J.Rodriguez

    Joined:
    Feb 25, 2007
    Messages:
    2,827
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Orlando, FL
    My dad had the exact same problem on his 05 V6.
     
  6. atlanticblue98

    atlanticblue98 Bazinga!

    Joined:
    Jun 19, 2008
    Messages:
    7,361
    Likes Received:
    3
    Trophy Points:
    48
    Location:
    Orlando, FL
    Our 07 hasnt had a problem, how many miles did your's have?
     
  7. JustSpeed7

    JustSpeed7 J.Rodriguez

    Joined:
    Feb 25, 2007
    Messages:
    2,827
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Orlando, FL
    60,000 something I think it has 78,000 now, lol.
     
  8. atlanticblue98

    atlanticblue98 Bazinga!

    Joined:
    Jun 19, 2008
    Messages:
    7,361
    Likes Received:
    3
    Trophy Points:
    48
    Location:
    Orlando, FL
    i guess we wont have to deal with it for a while, the 07 has 32,000 :lol:
     
  9. bonemanrides

    bonemanrides Logophile, Curmudgeon

    Joined:
    Apr 13, 2005
    Messages:
    687
    Likes Received:
    0
    Trophy Points:
    26
    Location:
    Cape Coral, FL
    Yeah... my original plastic T-stat housing failed at 147K miles. Replaced it with another plastic housing... and that failed a year later with all of 5000 miled driven. Since I'll be keeping the car for a while yet, I opted out of the plastic junk... and procured an aluminum unit. It is bulletproof.
     
  10. pacbelt

    pacbelt 6 Pistons, less mass = POWER Potential!!

    Joined:
    Mar 9, 2016
    Messages:
    57
    Likes Received:
    11
    Trophy Points:
    8
    Location:
    Surface of the Sun, AZ
    WHERE do you get the aluminum thermostat from???
     
  11. Phil II

    Phil II Cone Destroyer Staff Member

    Joined:
    Sep 19, 2013
    Messages:
    1,421
    Likes Received:
    207
    Trophy Points:
    73
    Location:
    Columbia, South Carolina
    I believe EBay
     
    pacbelt likes this.
  12. pacbelt

    pacbelt 6 Pistons, less mass = POWER Potential!!

    Joined:
    Mar 9, 2016
    Messages:
    57
    Likes Received:
    11
    Trophy Points:
    8
    Location:
    Surface of the Sun, AZ
    I found it, thanks!! ;)
    Amazon has them too, same price.

    .... Wonder if I could use the one for the Exploder? It has a second sensor hole... if needed in the future.
     
    Phil II likes this.
  13. Phil II

    Phil II Cone Destroyer Staff Member

    Joined:
    Sep 19, 2013
    Messages:
    1,421
    Likes Received:
    207
    Trophy Points:
    73
    Location:
    Columbia, South Carolina
    Well, it is the same engine
     
    pacbelt likes this.