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Technical Coolant loss, white smoke mystery

Discussion in 'The Hokey Ass Message Board' started by dhowlan, Nov 5, 2020.

  1. dhowlan
    Joined: Oct 19, 2009
    Posts: 20

    dhowlan
    Member

    My brain hurts so I'm sharing in the hopes the collective has some great input that gets me to an answer to this puzzle.

    Engine is a 225 slant six chrysler. I have been chasing a coolant loss issue for a couple of years. The engine has about 6k miles since rebuild years ago. Head was also rebuilt at that time with larger valves. Head was magnafluxed at that time. For years I had no cooling loss issues. Then, I acquired a pinhole leak in the radiator and I replaced the entire external cooling system with a better (clearly) system including new radiator, hoses, fan clutch, overflow, etc. Despite that, the coolant has continued to disappear. No leaks anywhere.

    In May, I replaced the head gasket. At the time I replaced the head gasket, symptom was only loss of coolant. Car ran fine. Never overheated. (I don't know if it has overheated in some areas of the head/block because, as I said, coolant loss, but the temp gauge has never given a concern.) At that time, I put a pressure tester on the radiator and it held pressure until I removed the intake/exhaust manifolds (they are connected on this engine). The leaking noise came from the number 6 intake port. The runner had coolant remains in it. I replaced the head gasket. It looked at the time like the coolant was migrating from the passage near the #6 (this is the rear of the head, where the coolant comes out of the block and then returns to the block) and somehow entering the cylinder. I did my best to check for flatness with my way to short metal edges. I didn't see any obvious cracks.

    I thought that would be that, but the coolant has continued to leave, despite the fact the pressure tester shows it holding pressure for hours. So yesterday, when I started it, it cranked in a very bad way. Immediately made me think hydrolock. Tried a couple of times and then it started. Drove off but it felt like something wasn't quite right. I'm expecting the worse so I'm looking in my mirror for white smoke. After maybe a quarter mile, white smoke. Lots.

    So today I'm checking things. Cooling system still holds pressure. Still no oil in the coolant. Still no coolant in the oil. I removed all the plugs. Number six looks whiter than it should. I did a compression test. 1-5 are between 155-165 psi. It cranked slower than i thought it should, but it's been a while since i've done this. Number six was a real head scratcher. Keep in mind, all plugs are out. With the compression gauge attached, the engine would not crank beyond once or twice. It tried, but eventually click click click. I tried again with a battery jumper hooked up. Nope. Gauge was at about 90 psi.
    So I put a wrench on the crankshaft and turned it by hand. There was a sound like maybe a ring freeing itself and then it turned as if nothing was off. I put the pressure tester back on with the valve cover off, still holds pressure, no noise from anywhere (and i am peculiarly sensitive). I turned the engine over by hand through a whole cycle but still no leaks anywhere. I was totally expecting the intake to open and whoosh, but nothing. And it still won't crank easily with the starter.

    Before i go removing more things, I'd really like to narrow down a path to success. Ideally I'd like to know if the head is cracked or the block is cracked or ??? and I don't want to remove the head and then find out I shoulda tested something while it's still installed. I hope this all makes sense. I'll post pictures from the head gasket replacement when i have a chance (and track them down).

    Any ideas? Thank you in advance.
     
  2. Yes, post the pictures. There has to be a leak in the; head, block, or head gasket. Close up pictures show better detail to attempt to get an issue like this on this medium.
     
    lothiandon1940 likes this.
  3. dhowlan
    Joined: Oct 19, 2009
    Posts: 20

    dhowlan
    Member

  4. dhowlan
    Joined: Oct 19, 2009
    Posts: 20

    dhowlan
    Member


  5. squirrel
    Joined: Sep 23, 2004
    Posts: 55,942

    squirrel
    Member

  6. dhowlan
    Joined: Oct 19, 2009
    Posts: 20

    dhowlan
    Member

    Sorry, let me fix that.
     
  7. dhowlan
    Joined: Oct 19, 2009
    Posts: 20

    dhowlan
    Member

    How about now?
     
    VANDENPLAS likes this.
  8. Happydaze
    Joined: Aug 21, 2009
    Posts: 1,904

    Happydaze
    ALLIANCE MEMBER

    Your writing skills in terms of clearly explaining the problem and measures already taken are admiral and to be applauded. Your picture posting skills aren't! :)

    Chris
     
    warhorseracing likes this.
  9. dhowlan
    Joined: Oct 19, 2009
    Posts: 20

    dhowlan
    Member

    Thank you, I think. :)
     
    VANDENPLAS likes this.
  10. dhowlan
    Joined: Oct 19, 2009
    Posts: 20

    dhowlan
    Member

    Can you see the pictures now?
     
  11. squirrel
    Joined: Sep 23, 2004
    Posts: 55,942

    squirrel
    Member

    Yes, thanks
     
    VANDENPLAS likes this.
  12. squirrel
    Joined: Sep 23, 2004
    Posts: 55,942

    squirrel
    Member

    Interesting bore surface. It's pretty hard to tell what's going on here from a photo, but there might be some rust or pitting or crack or something? I can't tell.

    bore.jpg
     
    VANDENPLAS likes this.
  13. jaracer
    Joined: Oct 4, 2008
    Posts: 2,419

    jaracer
    Member

    I would put air in the cylinder and check for bubbles in the radiator. If I didn't see any bubbles with #6 at TDC, I would remove the rocker arm assembly and move the piston down in the cylinder. That way you have the valves closed and can see if you have a cylinder problem. I see some things in # 6 cylinder wall that look a little suspect, but it's hard to tell from pictures.
     
    bchctybob likes this.
  14. dhowlan
    Joined: Oct 19, 2009
    Posts: 20

    dhowlan
    Member

    I don't have a leakdown tester at hand. I'll see about getting one.

    Also, I've been thinking of increasing the coolant pressure tester pressure beyond 16 lbs. (which has remained rock solid this whole conversation). Now that i think about it, makes more sense from the other end. Never mind that. Leakdown tester on the list.
     
    VANDENPLAS likes this.
  15. old.hot.rodder
    Joined: Oct 13, 2012
    Posts: 287

    old.hot.rodder
    Member

    The last time I saw a cylinder wall like that it was on a old 350 Chevy. In my case it was smoking white smoke like you. After I tore the motor down I realized the wall was corroding from the inside. I hope this is not your case. A pressure test does not help you in this with this problem.
     
  16. I agree with Squirrel about the "interesting bore surface". No crosshatch evident anywhere.
    bore marked.jpg
    The yellow circle looks like pitting. The white looks like water or rust stains. The blue appears to be piston scuffing the cylinder wall. The orange may be a crack. When this engine was rebuilt was it checked for cracks or sonic checked for cylinder wall thickness? You state that 6000 miles since the rebuild but those cylinder walls don't tell that few miles with no cross hatching from the honing.
     
  17. spanners
    Joined: Feb 24, 2009
    Posts: 2,074

    spanners
    Member

    I'm no expert on slant sixes, but if there is hissing coming from the intake valve port is it possible that when the larger valves were installed a crack has formed letting coolant from the head into the port area?
     
    VANDENPLAS, 427 sleeper and squirrel like this.
  18. indyjps
    Joined: Feb 21, 2007
    Posts: 5,377

    indyjps
    Member

    Looks like an engine that sat with rusted cylinders, then got started. Doesnt really help with the coolant issue. o_O
     
  19. What head gasket did you use on replacement?
    Any head bolts go through coolant jackets ?
    Does the intake have coolant passages ?
    What gasket was used on the intake etc ?
    Name brand ? Chinese cheapo stuff ?
    You can do a leak down on that cylinder, may or may not show you anything.
    Was the block and head checked for straightness ?

    those lines and scuffs etc on the cylinder wall don’t give me the warm and fuzzies .

    how much coolant is your engine eating ?

    had a in-line 6 years ago that would “ nip” coolant .... maybe a 1/2 litre every 100 kilometres , ended up being a small crack in the cylinder head.

    good luck


    Maybe get one of those coolant exhaust sniffer tools, I have one and it works really well. In situations like this to find exhaust gasses in the cooling System.

    AD29CE9C-42C4-4833-AEF5-53E9E9A1A2B7.png
     
    sunbeam and warhorseracing like this.
  20. junkman8888
    Joined: Jan 28, 2009
    Posts: 1,035

    junkman8888
    Member

    This is what you need to do: If the cylinder head isn't still on the engine grab a used head gasket, slobber both sides with wheel-bearing grease, put the head back on the engine and torque everything down. Next, remove the hoses from both the radiator and heater core, then plug all hoses and fittings going to the engine cooling system with PVC plumbing caps and pipe as needed. (The reason you disconnect the radiator and heater core is so they won't get damaged from high air pressure) Fill the engine cooling system with water or soap and water through the uppermost hose, cap the hose then apply shop air through a Shrader valve mounted in the cap. In other words you're pressurizing the cooling system, not the individual cylinders.

    Then once you realize your engine is DOA, you can replace it with a 318, or a 360, or a Hemi.
     
    warhorseracing and caseywheels like this.
  21. Your statement of the engine turning over hard makes me wonder if you don't have a bent connecting rod. From what you are describing, you had a coolant leak in an intake passage. The leak was prominent when the engine was hot. Upon parking the engine in the suspect cylinder, it may have had an intake valve open and allowed it to hydraulic. I know it's no fun but if you value the engine, pull the pan and see what there is. usually a bent rod is pretty obvious. Good luck with your diagnosis.
     
    Desoto291Hemi likes this.
  22. dhowlan
    Joined: Oct 19, 2009
    Posts: 20

    dhowlan
    Member

    ok. so many questions.

    Let's start with the photo. I wouldn't trust much about a phone camera flash photo. But, as is obvious, it looks odd. The engine wasn't rusted before it was rebuilt. However, i agree, it looks funky. I never noticed the flaky part until I pulled up the photos. It is concerning. It's bored 30 over stock. Deck and head were flat in the beginning.

    Yes, a crack in the port area is one of my thoughts. While looking for these photos, I found the photos of the first head I attempted to get machined. It came back from magnaflux marked "junk" as it had cracks in 5 places, mostly between the valves. (Amazingly, none in the area where mine is suspect.)

    The head gasket is felpro as was the previous gasket.
    Many manifold studs go through to the water jacket. None of the head bolts do.
    Intake does not have coolant passages (Offy).
    Intake/exhaust gasket is similar to remflex, can't remember the name. Australian. Thick.

    I will take a 360 if it falls in my lap. Donate now. :)

    Just to reemphasize, the photos are not now. They are from when I replaced the head gasket in May. Right now, everything is still put together.

    I'm still liking the pressure in the cylinders option. I think if I can get the coolant to travel somewhere I can narrow down what's leaking.
     
    VANDENPLAS and bchctybob like this.
  23. dhowlan
    Joined: Oct 19, 2009
    Posts: 20

    dhowlan
    Member

    I've ordered a leakdown tester and an endoscope. We'll (hopefully) see. o_O
     
    fauj likes this.
  24. GTS225
    Joined: Jul 2, 2006
    Posts: 1,244

    GTS225
    Member

    OK......you dropped bigger valves in it. Was any port work done? (i.e. bowl cleanup, enlarging, etc.?)

    I know that the walls between the water jacket and valve ports get pretty thin in places, and it occurs to me that it may have been fine for years, but slowly developed a crack or pinhole in that cylinder's port, and therein lies your problem. Might be something to keep in mind.

    Roger
     
  25. lippy
    Joined: Sep 27, 2006
    Posts: 6,825

    lippy
    Member
    from Ks

    I see three cyls from the pics that look different. ie, clean and white valves. Could the problem be from bigger valves being fitted and be the valve seats that were installed leaking? Are you sure the head is good? Maybe it's not the head gasket, maybe it's the head itself. Blocks very seldom have a problem. Lippy
     
    Desoto291Hemi likes this.
  26. Vimtage Iron
    Joined: Feb 28, 2010
    Posts: 561

    Vimtage Iron
    Member

    Leaks like that are hard to find some days, even over pressuring the radiator may not get you there, I had one of the Peterbilts dump all the water in the basement, I was pretty sure it was liner or o rings so with the pan off I finally pressured the system to about 20 pounds and still no leak, I gave up and tore the engine down and it was a liner that pinholed, but it wouldn't leak cold.
    U was going to also ask if head bolts went into water jackets, but I see they don't, if the manifold bolts do is there a chance of leak thru bolt threads or crack into manifold.
     
    RidgeRunner likes this.
  27. David Gersic
    Joined: Feb 15, 2015
    Posts: 2,730

    David Gersic
    Member
    from DeKalb, IL

    If you’re going to try one of these, they’re free at AutoZone. You “rent” the tool, which is just a credit card hold to make sure it comes back. You also “rent” the fluid, and return the empty bottle.

    No, that doesn’t make sense, but that’s how they do it.



    Sent from my iPad using The H.A.M.B. mobile app
     
  28. dhowlan
    Joined: Oct 19, 2009
    Posts: 20

    dhowlan
    Member

    Funny about Autozone. I went to harbor freight to buy a leakdown tester, they had zero and the Autozone was next door. I went over there and there was a handwritten sign on the door, "Closed. Computer Problme" Yes, Problme. So I didn't get to check if they had one and I really worried about the staffing of that place.

    Anyhow, thanks for all the input. To clarify the head work. The only thing done besides valves and valve seats was me matching the volume. Very little material was removed.

    Also, I should never rely on my brain to remember anything temporal. 17k miles since it was originally put together. I have zero idea how long this particular issue has been going on. Clearly too long.

    The endoscope is an amazing piece of kit.
    The last one is the top of the bore transition to the head gasket and then the head. The camera has a hard time looking up because of the tight bend. It has a 90 degree mirror adapter, but it's so close to the head it's hard to see much or see clearly.

    Leakdown is 25%. I had to disable the rocker to stop the pressure from rotating everything. No bubbles in the coolant. Some noise at the dipstick. Nothing to speak of at the tailpipe. Nothing out the throttle body. Nothing out the spark plug holes. Most all the noise inside the cylinder area.

    The coolant seems to be seeping from the head area. You can see in the one picture a trail. The valve bottoms look dry. (really hard to get a picture of that). I vacuumed it out last night and it was back in the morning.

    I guess the head is coming off next. Have I mentioned I hate this head?

    We may seriously start discussing 360s shortly.
     
    VANDENPLAS likes this.
  29. harpo1313
    Joined: Jan 4, 2008
    Posts: 2,584

    harpo1313
    Member
    from wareham,ma

    Thats not good at all. The two 360s I had were thirsty suckers.
     
  30. Bbdakota
    Joined: Oct 23, 2019
    Posts: 81

    Bbdakota
    Member

    360 magnum is not as bad as early model and can make pretty good power when the combination is right
     
    das858 likes this.

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