2007 GMC Sierra has black colored sludge in coolant?


I have a 2007 GMC Sierra 3500 less than 10000 miles has black colored sludge I can see in my coolant system causing problems with apparently so much blockage of this that causing it to overheat ?


The most common cause for this would be an internal leak in the radiator, meaning the transmission fluid is contaminating the coolant and causing the sludge. This would be considered a manufacturer defect and should be covered under warranty. Having the dealer replace the radiator and flush system would be the fix.

Another thing that can cause this would be if you/someone put mixed the wrong type of coolant with what is already in it (if they added green coolant) this will cause the coolant to turn brownish/black and sludge up. complete flush and fill of system would be the fix.


  1. Excellent weblog here! Additionally your site rather a lot up very fast!
    What host are you the use of? Can I get your affiliate link
    for your host? I want my website loaded up as quickly as
    yours lol

  2. Right here is the perfect blog for anybody who wishes
    to understand this topic. You know a whole lot its almost
    tough to argue with you (not that I actually
    would want to…HaHa). You certainly put a brand new spin on a subject that has been discussed for
    a long time. Great stuff, just excellent!

  3. Hey there! This is my 1st comment here so I just wanted to give a quick
    shout out and say I genuinely enjoy reading through your blog posts.
    Can you recommend any other blogs/websites/forums that go over the same
    subjects? Appreciate it!

  4. I’ve been exploring for a little bit for any high-quality
    articles or weblog posts on this sort of area .
    Exploring in Yahoo I eventually stumbled upon this website.

    Reading this info So i’m glad to express that I’ve a
    very excellent uncanny feeling I came upon exactly what I needed.
    I such a lot definitely will make certain to don?t fail to remember
    this website and give it a glance on a constant basis.

  5. It’s truly very difficult in this full of activity life to
    listen news on TV, therefore I just use world wide web for that purpose, and obtain the most recent information.

  6. You can definitely see your skills in the article you write.
    The sector hopes for even more passionate writers such as you who are not afraid to mention how they believe.
    Always follow your heart.

  7. When I originally commented I clicked the “Notify me when new comments are added” checkbox and now each time a comment is added I get four e-mails with the same comment.

    Is there any way you can remove people from that service? Thanks!

Leave a Reply

Your email address will not be published. Required fields are marked *