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STUPID JEEP....Overheating!

Discussion in 'Flat Fender Tech' started by sammy, Jun 3, 2009.

  1. sammy

    sammy Coca-Cola?

    No, it's a recore now done by a local shop, basically the old tanks with new fins and tubes. I'm thinking maybe just do an aluminum radiator anyway.
    How could it get clogged though? It has like 15 miles on it, maybe 4 hours tuning idling revving and it has had 50/50 in it since I knew it wouldn't leak it out (was water before then)
     
  2. jpflat2a

    jpflat2a what's that noise?

    sounds like oil in the water..not good
     
  3. sammy

    sammy Coca-Cola?

    expand please jim.
     
  4. Patrick

    Patrick Super Moderator Staff Member

    Brown sludge could be engine oil in the coolant. Bad head gasket or a crack somewhere.
     
  5. sammy

    sammy Coca-Cola?

    how would I test for this?
     
  6. jpflat2a

    jpflat2a what's that noise?

    brown sludge bad...newly cleaned block and radiator.
    milkshake
    maybe take a sample and have it analyzed by a lab locally ? Cat dealer etc...
     
  7. sammy

    sammy Coca-Cola?

    I'll grab a sample.
    What's stumping me is, it was green until the last bit of coolant, then brown thicker stuff. How would oil in the coolant be from a bad head gasket?
     
  8. Bill F

    Bill F Finally running

    Before getting to worried about cracks, how clean was the inside of the block when you put things back togheter? Did someone put oil in the water jacket to keep rust from happening? Hook a vacume guage up to the engine, it will tell you if your head gasket it gone, you can also do a compression test.
     
  9. w3srl

    w3srl All-around swell dude Staff Member

    Your FLAPS should also have a cooling system leakdown tester that you can use for free. Basically, it installs over the rad cap opening and you use a hand pump to pressurize the cooling system and watch for the pressure to leak down. If it drops significantly, you have a hole in the cooling system, which can be a number of things.
     
  10. jeep2003

    jeep2003 Well-Known Member

    could it be a bad or improperly installed waterpump ? not sure how its designed on these engines
     
  11. w3srl

    w3srl All-around swell dude Staff Member

    Rethinking this, with a good rad and water pump you shouldn't need an electric fan to keep things cool with a stock flathead. The factory fan and shroud setup moves a lot of air, and even under some pretty harsh low-speed punishment I've never had any one of my 3 CJ2A's overheat. This is under some 90* and 90+ humidity conditions.

    Just thinking out loud, did you re-torque the head bolts after break-in?

    Have you tried taking the rad cap off (cold) and bringing the jeep up to temps at idle? Look into the rad to see if there are air bubbles, which would indicate a crack or a bad head gasket.
     
  12. LarryD

    LarryD Member

    Sammy,
    I had an overheating issue with my F head, I replaced the t-stat had the radiator checked by the rad shop replaced the waterpump and finally replaced the belt with one !" shorter. I had checked the belt tension several times and thought it was plenty tight but it was adjusted all the way out. I thought it was plenty tight and wasn't squealing and appeared tight but with the shorter belt you can't make it run hot. It will idle for an hour at a time and the temp guage sits right at 190.
     
  13. sammy

    sammy Coca-Cola?

    Larry, I have yet to get a real rubber belt on.... But, the belt I have has a lot of tension on it. I'm swapping on a rubber belt when I get to it though
     
  14. sammy

    sammy Coca-Cola?

    Ok, 180* thermo and retainer in (actually had one in and didn't know it, well...what was left of it...) prestone mix 60/40, was considering 70/30 as well.
    Need to get a belt. Pretty sure I burped it as well.


    What kind of rad cap should I be running? what should the pound reading be?
     
  15. Bill F

    Bill F Finally running

    7 lbs cap is what you need
     
  16. sammy

    sammy Coca-Cola?

    Replaced cap, replaced belt, timed it. Nope.
     
  17. RandyYJ

    RandyYJ Member

    Does it overheat while idling, or when running down the road pretty hard? I had this problem in my 4.0 until I figured out that I didn't torque down the head bolts enough. Mine would idle fine, but when I really got on it exhaust gases would push through and it would overheat. That was a tough one to find. Used the combustion tester on the radiator but when it was idling the gases would never push through.
     
  18. sammy

    sammy Coca-Cola?

    You do have a point, I was ripping out elms yesterday, barely idling and it got 195... but now today driving at about 2400 rpms (I got me a tach in cab :D) it went 200...210...220...

    I'm heading out to torque them now, BAM!
     
  19. sammy

    sammy Coca-Cola?

    How did I miss Steves post? Thanks Randy!

    Headbolts started turning at 40 foot pounds, should have been 65... LOL
     
  20. w3srl

    w3srl All-around swell dude Staff Member

    :)
    Posted via Mobile Device