Page 1 of 2 12 LastLast
Results 1 to 10 of 14

Thread: coolant bubbling in reservoir tank? Normal?

  1. #1
    Join Date
    Sep 2009
    Location
    Perth, Australia
    Posts
    58

    coolant bubbling in reservoir tank? Normal?

    Hi all,

    I actually noticed a while back that the coolant bubbles up in the reservoir, and that it bubbles up harder when you rev the car. Is this normal or a symptom of something that has gone wrong? Temp is always at the same mark - just a tad over half way.

    History: I replaced the radiator about 6 months ago, as it was leaking where the core meets the end tanks. Have always been wondering whether this bubbling was linked to it somehow.

    I 'googled' the bubbling and apparently it's normal, but I'd rather be sure, that all other D2's do the same thing.

    Thanks in advance,

    ffdisco2

  2. #2
    Join Date
    Aug 2006
    Location
    Melbourn(ish)
    Posts
    24,485
    bubbles are bad...

    if your coolant is bubbling your head gasket is on the way..

    IF however its being caused by the return flow from the radiator areating the coolant in the bottle thats ok.

    If its any help I normally define the "bubbling" that occours when its the return coolant areating the fluid in the tank as "frothing" it looks similar to the coolant flow in an old school engine thats being run on low coolant level and the pump is cavitating.
    Dave

    "In a Landrover the other vehicle is your crumple zone."

    For spelling call Rogets, for mechanicing call me.

    Fozzy, 2.25D SIII Ex DCA Ute
    TDI D1(its responded well to its lecture about poor performance)

    If you've benefited from one or more of my posts please remember, your taxes paid for my skill sets, I'm just trying to make sure you get your monies worth.
    If you think you're in front on the deal, pay it forwards.

  3. #3
    Join Date
    Jan 1970
    Location
    Adelaide Hills - SA
    Posts
    12,516
    With the engine cold, or just a little warm, take off the lid of the expansion tank.

    Start up your engine and place your palm over the opening of the expansion tank.

    Can you feel any pressure? If you lift your palm off a bit, so the seal is broken, do you get a little pop of air?

    Sounds very like a head gasket, but give the above a try and see what you discover.

  4. #4
    Join Date
    Sep 2009
    Location
    Perth, Australia
    Posts
    58
    Thanks for the advise.

    I should explain what's happening isn't 'bubbling' in the sense where bubbles are forming. It could be better described as a disturbance, similar to holding a garden hose under water in a bucket, with the hose pointing up. Is this something that happens on other D2's?

    spudboy: I just tried as you suggested engine cold (so thermostat should have been closed/no flow), there was no pressure building up which is a good sign i guess. I'll do this again at work tomorrow, I'm sure the neighbours don't appreciate the the car rumbling away this time of the day. I did however, at one point feel a little bit of vacuum on my hand could this have been the thermostat opening and flow starting???

    Will let you know how I go tomorrow with it. Hopefully it's just flow as blknight pointed out. If it starts doing it when it is cold I guess I'll start worrying again.

  5. #5
    Join Date
    Jan 1970
    Location
    Adelaide Hills - SA
    Posts
    12,516
    I have done it on a warmed up engine, but I was just making sure you didn't just open the cap and get scalded or anything. Come to think of it, maybe the engine should be warmed up to test this!!

    I am just a farmer - so someone with better mechanic skills might advise whether hot or cold makes a difference.

    All I know is, if you get pressure on your palm and things "deep gurgle" inside the system, the head gasket is probably leaking. Hopefully for you, it is not the case on your engine.

  6. #6
    Join Date
    Jan 2011
    Location
    Gold Coast
    Posts
    289
    My td5 has a constant flow of coolant going into the overflow tank. This could prob be mistaken as bubbling.
    For bubbles to be created in the over flow tank and it be head gasket related this would mean exhaust gases carbon dioxide (diesel) or carbon monoxide (petrol) would be traveling into the cooling system from the combustion chamber. This would definately make the engine over heat by pressurizing the expansion tank and forcing the coolant out of the relief hose. If your not loosing coolant I doubt it's head gasket related.
    Michael.

  7. #7
    Join Date
    Aug 2010
    Location
    Karratha WA
    Posts
    159
    Be careful with the "hand over" trick, because the design on the neck is such that the overflow is open once the cap is less than 1/2 a turn off its seat, which means putting your hand over the neck won't do anything because the overflow pipe is open an venting. You will need both hands...one to place a finger over the overflow tube.
    Of course if the engine is run for a period of time, you will build pressure anyway simply because the coolant expands (like any fluid) as it's heated, and in fact, you may self delusion bubbles, as the coolant cavitaes at the water pump as it heats up, and imitates the effect of boiling at the tank.
    As pacemaker said..."If your not loosing coolant I doubt it's head gasket related."

  8. #8
    Join Date
    Jun 2009
    Location
    Melbourne
    Posts
    472
    It sounds to me like it's just the fluid pumping through the tank and not much of a concern.

    I concur that if you're not losing coolant, then you probably don't have a head gasket leak.

  9. #9
    Join Date
    Sep 2009
    Location
    Perth, Australia
    Posts
    58
    cheers everyone. I'll keep an eye on it. Hopefully it's not a head gasket issue. fingers crossed.

  10. #10
    Join Date
    Aug 2009
    Location
    Point Cook, Vic
    Posts
    123
    Hey mate A big thing I missed about coolant bubbling i had, Only lost coolant when it was on the road. had a "fish tank" gurgiling sound for some time.
    I pulled the whole car apart, all hoses cleaned up, rad return replaced (snaped) new tank cap, thermostat, rad flush out, water pump cleaned out and new seals, flush engine, new viscos fan.

    still bubbling, fish tank noise.........smoke steam and black water out exhurs...... tow truck to mechanic to do engine

    found gasket cracked into rear cylinder water slowly filling cylinder.
    but as water/steam filled cylinder slowly burnt out part of gasket and then melted head.

    $5000 later for works new engine and big lesson learnt.

Page 1 of 2 12 LastLast

Bookmarks

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Search AULRO.com ONLY!
Search All the Web!