Bubbles in coolant reservoir?

Discussion in '80-Series Tech' started by tim.korn.99, Aug 26, 2011.

  1. tim.korn.99

    tim.korn.99

    Messages:
    764
    Location:
    Northwest Arkansas
    Y'all have me paranoid about HG issues. I don't know if the one on my 80 has ever been replaced before, but I do know that all of the coolant hoses (including PHH) was done.

    I'm very religious about maintenance (as seems to be the case on this site). I completely check the cruiser over bi-weekly. So if ANYTHING is out of place, I'll know it.

    Well, I noticed that my coolant level was a tad low (like 1" below the line where it usually resides) over the course of about 1500 miles.

    My mind immediately jumped to the HG... Thanks guys.



    Backgroud:

    Extremely well maintained, doesn't leak a drop of anything, BUT it does appear to be a little wet on the very bottom of the radiator. BTW, it's a new radiator with around 5k on it.
    So, that would probably explain where the bit of coolant leaked out, and why it no longer sits at the FULL mark.

    Case closed right?



    Well, for some reason I still couldn't sleep well, dreaming about HG issues. :doh:

    So I do tons of research on here, and read about this "Bubble test" that you can perform.

    Keep in mind that I'm very mechanically inclined, have built many motors from the ground up, and have encountered headgasket issues on other vehicles in the past. So I'm well aware of what burning coolant smells like, and what normal coolant should smell like.


    While the cruiser is fully warmed up, I have my wife hop in and gently bring the revs up to the 3,000rpm mark, while I watch down inside the coolant reservoir.

    That's when my gut churned. After holding at the 3k mark for a few seconds I saw a couple bubbles, then a couple more. After that, it was about 1-2 bubbles every second.


    Since then, I've performed every test I know to do on the cruiser, so I'll break down what's been done, and what I know so far:

    - Purchased/Used block sniffer 4 separate times on 2 separate days. Perfectly clean results. And just so that I would know what "yellow" looked like, I held the sniffer in front of the tail pipe once...

    - No cooling issues

    - Runs absolutely perfect

    - No fuel smell in the radiator or the reservoir

    - Oil is extremely clean (doesn't burn any between 3k changes)

    - No "milky sludge" under the oil cap, or at the top of the dipstick tube

    - No smoke/coolant smells out the exhaust

    - Coolant is very clean and clear



    All of that tells me that the headgasket is probably fine. However, there are still bubbles in the reservoir when held at 3,000 rpm.


    My question is (and a long way to go about it):

    Are some bubbles in the reservoir normal? I was unable to find a definite answer on that.

    Also, my radiator cap IS original. Think that might have something to do with seeing bubbles?



    Any light you can shed on the subject is greatly appreciated.

    :beer:
  2. Layonnn

    Layonnn

    Messages:
    1,933
    Location:
    Baton Rouge, LA
    Bubbles while the engine has been running for a while are not normal.
    At startup possibly, and after refilling the radiator and getting any air out of the lines, yes. But not after its been running for a while, you shouldn't see air being introduced into the lines.

    I wouldn't think that the gasket on the radiator cap is an issue (could certainly be wrong).
    I have ran mine (cold) with the radiator cap off and didn't see any bubbles just to check it.

    Sorry, thats as much help as i can offer on the subject.

  3. tim.korn.99

    tim.korn.99

    Messages:
    764
    Location:
    Northwest Arkansas


    Here's a bit more background:


    - I've not actually checked inside the radiator (with cap off) for bubbles.

    - I've only checked in the reservoir, with the radiator cap ON.

    - First time I checked it was right after I had the radiator cap OFF, and after reading it seems that it's normal to see some bubbles after that because of air being introduced

    - Second time I did bubble check, was approx. 100 miles after having the radiator cap off.



    Another observation: (see why I can't sleep?? :flipoff2:)

    After driving it this evening, I decided to do the sniffer test again WITHOUT shutting the cruiser off to remove the radiator cap.
    I've done this several times before on other vehicles, so I know how to release pressure slowly and not spray coolant everywhere.

    Well, there was very little to NO pressure under the radiator cap... Keep in mind cruiser had been driven 20 miles before hand and was fully warmed up.


    SO, based on that info, it looks like the cap is bad, right?
  4. Layonnn

    Layonnn

    Messages:
    1,933
    Location:
    Baton Rouge, LA
    A bad gasket on the cap could cause you to leak fluid, i would think.
  5. Sounds dead on like the symptoms of my rangie classic.All tests came out negative. Finally I did a chemical test, which proved that there was combustion gas in the coolant.
    Wish you better luck.
  6. Paul_L

    Paul_L

    Messages:
    549
    Location:
    Valencia, CA
    If your radiator is wet at the bottom, do a pressure test of the cooling system. My radiator leaked for a long time before I could track down my coolant loss. The plastic tanks can crack or leak at the seam with the metal core.

    Good luck.
  7. BrotherRob

    BrotherRob

    Messages:
    3,605
    Location:
    Scottsdale, AZ
    First off, get a new cap. If you're not holding pressure, you are likely loosing coolant and sucking some air into the system while the engine cools.:idea: If you had exhaust gases blowing into your cooling system, you would have had pressure in the system when you took the cap off the hot radiator.
    Second, stop obsessing about it. You've done everything to prove that the HG has failed and still can't confirm it. Either it's fine or it's not yet bad enough to be detectable.:meh: If you keep it up, you're likely to talk yourself into replacing a HG that may or may not be needed.:eek:
    Last edited: Aug 27, 2011
  8. gtfour43

    gtfour43 SILVER Star

    Messages:
    1,084
    Location:
    Middle of the Pacific :(
    I agree change the cap and get some sleep. That's a long time to be on the original cap. If you had a cooling system pressure tester you could test your cap but if you don't have one just replace the cap for a few bucks instead.
  9. Dave 2000

    Dave 2000 SILVER Star

    Messages:
    1,276
    Location:
    Spain
    Also remember the cap has two springs and valves not one like a typical old cap. I would do as advised and hit for a new OE cap, get some sleep and look at it in a couple of days. If your rad is wet at the bottom it could be water coming from a dud cap and reaching the bottom of the rad? If after you have a new cap your rad is still wet then then check all the hoses/clips. If all good then your new rad is toast, if the rad is toast then do not lose sleep deciding which one to buy, get OE or Koyo. Get back to us and let us know how you are doing after you have had some kip.

    regards

    Dave
    sheep.jpg
    Last edited: Aug 27, 2011
  10. tim.korn.99

    tim.korn.99

    Messages:
    764
    Location:
    Northwest Arkansas
    Thanks for all the advice, guys. I'm picking up a new cap today from the dealer.

    My plan is as follows:

    - Replace radiator cap

    - Monitor/check coolant everday for the next month

    - Use "block sniffer" once a week

    - I'll repeat the bubble test in one week, that should give time for air to be worked out of the system


    I'll continue monitoring every day until October 1st. At that point, if nothing has changed, and everything still looks good, I'll consider it good to go.
    However, if anything has changed in that time, I'm going to go ahead and have the HG replaced. I can't be worrying about that when winter rolls around...

    Also note, that I have a "sample" kit coming from Blackstone Labs. Once I receive it, I'll take an oil sample and send it off to them.


    I'll post results.


    Thanks!
  11. tim.korn.99

    tim.korn.99

    Messages:
    764
    Location:
    Northwest Arkansas
    Ok, I replaced the cap that same day. The system now holds pressure.


    Observations thus far:

    - Still no signs of HG failure (smell, smoke, residue, sludge...ect).

    - Bubbles are still there, let me explain:

    This morning, like every morning, I started the cruiser and immediately ran to the back to see if I could catch it expelling even a HINT of coolant smell or smoke. I waited a few minutes, until the idle dropped down to normal and the exhaust was hot. NOTHING.

    So I popped the hood and looked at the reservoir, and.........there were bubbles. Pretty steady stream of bubbles. And this was at IDLE. Bad news right?

    Well... Not so sure. After driving to work (30 miles), I popped the hood to see if it was still producing bubbles in the reservoir. NOTHING.


    So, what can that tell us?

    A.) The HG only leaks when cold? Possible, but I would expect at least SOMETHING coming from the exhaust.

    B.) Letting my truck sit overnight allowed some air in the system? Very possible, since I'm pretty sure there is a very small leak somewhere.




    Am I going to chance this being a HG problem? No way. I'm calling Dan today to get the HG parts coming, and I'll replace it next weekend. Honestly, I'm just tired of worrying about it....




    I'll update this thread tonight with results from the "Block Sniffer" tool. Maybe it will catch something this time?

  12. Paul_L

    Paul_L

    Messages:
    549
    Location:
    Valencia, CA
    It may just be air working it's way out.
  13. tim.korn.99

    tim.korn.99

    Messages:
    764
    Location:
    Northwest Arkansas
    I'm pretty sure that's it.

    Just checked it tonight when I got home and even had my wife hold the RPM up. No bubbles at all.

    Still planning to do the HG swap. No way of knowing if it was ever done on my rig, and it will make me feel better...
  14. Aww, come on! I replaced my HG in January in Colorado. It's not that bad.:meh::D

    You walk a not so fine line between being thorough and being neurotic. Well done!!!:clap:
  15. BrotherRob

    BrotherRob

    Messages:
    3,605
    Location:
    Scottsdale, AZ
    My HG had a separation of the firing ring on #1 and #6 that closed up as the engine warmed up. It was a very odd failure, I've never seen another like it.
    Three points to consider from my experience:
    When cold I lost compression in two cylinders, so it was nearly impossible to start but started and ran normally when warm. Secondly, because the breach occurred only when cold with the tstat closed, there were no bubbles and coolant loss was miniscule. Third, after starting the engine, my exhaust created a small, localized thunderstorm, once warmed up, nothing notable.
  16. Dgurley2000

    Dgurley2000

    Messages:
    187
    Location:
    DFW
    Still planning on replacing your head gasket? Would you do it yourself?
  17. skintunes

    skintunes

    Messages:
    692
    Location:
    piermont, NY
    saw this happen years ago on a 4cyl - might have been 22re- retorqued the head - and it drove around for another 100,000
  18. BrotherRob

    BrotherRob

    Messages:
    3,605
    Location:
    Scottsdale, AZ
    Lucky bastid, my 22re blew 3 head gaskets.:crybaby:

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