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HELP I THINK MY HEAD GASKET MAYBE GONE

Posted: Wed Apr 04, 2018 9:10 pm
by raseys
HI, RECENTLY I HAVE NOTICED ALOT OF MAYO APPREARING AROUND THE NECK OF THE OIL FILLER CAP AND HAVE HEARD OF IT CAUSEING HEAD GASKETS BEING THE CAUSE SO I CHECKED THE WATER LEVEL AND WAS GOOD SO THOUGHT ID CONTINUE TO MONITER THIS. (THIS WAS BEGINING OF LAST WEEK)

THURSDAY LAST WEEK - CHANGED OIL, FILTERS, PLUGS, DIST. CAP, INLINE FUEL FILTER. CHECKED RAD LEVEL. ALL WAS GOOD.

LAST NIGHT - CHECKED THE RAD LEVE - DIDNT THINK WAS LOW AND COULDNT SEE TOP OF RAD ON THE INSIDE.

THIS EVENING - FOUND MAYO ON DIPSTICK, WATER LEVEL IN RAD LOW (COULD SEE INSIDE OF RAD) (HAVE NOW TOPPED BACK TO TOP)

DOES ANYONE KNOW IF A GONE HEAD GASKET WOULD BE CAUSING THESE SYMTOMS. AND ARE THEY ANY SIMPLE TEST TO RULE OUT ANYTHING ELSE BEFORE DOING A COMPRESSION TEST.

Re: HELP I THINK MY HEAD GASKET MAYBE GONE

Posted: Wed Apr 04, 2018 10:28 pm
by philthehill
The mayo can be caused by the use of a wrong engine oil or the engine not getting hot enough.
Having mayo does not always mean that the head gasket has failed.

A simple check is to fill the rad to the top and see if any bubbles appear at the filler neck.
If they do then suspect a failed head gasket and carry out a compression test.

Re: HELP I THINK MY HEAD GASKET MAYBE GONE

Posted: Thu Apr 05, 2018 7:34 am
by oliver90owner
Agree wuth what Phil says. A failed fire ring is not the only way that a head gasket can fail and a compression test may not show up a very slightly leaking fire ring.

Not necessarily appliccable to this engine, but core plugs, cracked cylinder walls, O-rings on wet liners, cracked blocks, porous blocks and a few other reasons can be traced as culprits of oil in the water or water in the oil, depending on the pressure differentials involved.

Re: HELP I THINK MY HEAD GASKET MAYBE GONE

Posted: Thu Apr 05, 2018 7:56 am
by kennatt
take the rad filler cap off start engine and let it tick over until hot,rev engine via cable to carb and watch water level in rad ,if head gasket gone water will be pushed out of the rad since gasket failure lets combustion products into water system causing over pressurization. Alternatively get it hot with cap on and feel the top hose, squeeze it, it should be firm but not rock hard. be causeful the water will be hot,obviously don't take cap off when hot.The mayo is caused ,usually because of cold running,the moggie engine is overcooled as standard,in the winter air flow over the rocker cover cools it even further ,some take the fan off to prevent this in the winter, if all is well gasket wise and you are still loosing water take it to a garage and ask them to do a pressure drop test on the water system it will show if you have a slight leakage somewhere. Good luck.

Re: HELP I THINK MY HEAD GASKET MAYBE GONE

Posted: Thu Apr 05, 2018 7:59 am
by myoldjalopy
philthehill wrote: Wed Apr 04, 2018 10:28 pm A simple check is to fill the rad to the top and see if any bubbles appear at the filler neck.
For the sake of clarity, Phil, presumably with the engine warmed up and running? I don't think just filling the rad will show bubbles if the gasket is gone - it has to be run as well, I guess.

Re: HELP I THINK MY HEAD GASKET MAYBE GONE

Posted: Thu Apr 05, 2018 4:53 pm
by kennatt
see post above

Re: HELP I THINK MY HEAD GASKET MAYBE GONE

Posted: Thu Apr 05, 2018 6:03 pm
by philthehill
myoldjalopy
I would have considered that it could be taken as read that the engine is running as you do not get compression with the engine not rotating.
No compression = no bubbles.

Re: HELP I THINK MY HEAD GASKET MAYBE GONE

Posted: Thu Apr 05, 2018 8:08 pm
by myoldjalopy
Yes indeed Phil, I'm not pedantic but its just (without making any assumptions about the OP) we don't always know the level of knowledge of some people asking questions on this forum. There was a time when I would not have understood what compression was myself....... I am reminded of a girlfriend who was caught trying to top up the engine oil through the dipstick hole! :roll:
Cheers,
Pete

Re: HELP I THINK MY HEAD GASKET MAYBE GONE

Posted: Thu Apr 05, 2018 8:30 pm
by palacebear
Sorry ... thread drift... reminds me of a woman who asked me for help in a petrol station shop. She was searching amongst the oils and brake fluid etc., because she needed to buy 'a can of petrol' :lol:

Re: HELP I THINK MY HEAD GASKET MAYBE GONE

Posted: Thu Apr 05, 2018 9:14 pm
by raseys
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

Re: HELP I THINK MY HEAD GASKET MAYBE GONE

Posted: Thu Apr 05, 2018 9:35 pm
by les
Something you might try is to remove the plugs and by using the starter motor or pressing the solenoid button, turn the engine over and see if any water sprays out of the plug holes, this would likely indicate head gasket.

Re: HELP I THINK MY HEAD GASKET MAYBE GONE

Posted: Thu Apr 05, 2018 9:44 pm
by raseys
OKAY WILL TRY THAT TOMORROW AND REPORT BACK

Re: HELP I THINK MY HEAD GASKET MAYBE GONE

Posted: Thu Apr 05, 2018 10:24 pm
by oliver90owner
If water ‘sprays’ out, you would already know you had a failed head gasket - it would only confirm it! There would only be about a Bar and a bit pressure differential between the cooling system and the combustion chamber, at most (engine very hot and radiator cap working correctly). The compression pressure and power stroke would provide a much greater pressure and force combustion gases into the cooling system while running. The engine might well ‘hydraulic lock’ if water were leaking that fast.

A compression test is more likely to show zilch if the gasket has blown between numbers 2 and 3. Valves and rings are also part of that test - like did you check the valve clearances before testing? Did you do a dry and wet test? Water can get from the cooling system to the sump via other ways than a compression test would show.

Also, there is no water flow between Nos. 2 and 3 cylinders - the distance is minimal.

Your head gasket could well be leaking. Nobody has disputed that. By all means, change it if you must, but far better to diagnose the fault properly before doing unnecessary work and then finding it was not the fault.

Gases into the cooling system is a far better indication of a failing head gasket. And, of course, the antifreeze pH will be much lower than it should be, so will have changed colour.

MOJ,

Did you date my daughter? On second thoughts, likely not. She knew the oil level on her metro was low but did not know there was a filler cap, so topped up the oil via the dipstick tube and carried on driving. Sensible girl - she got the job done - and she was a quick learner when shown.

Re: HELP I THINK MY HEAD GASKET MAYBE GONE

Posted: Thu Apr 05, 2018 10:31 pm
by les
Try the water test anyway, despite the comment of ' you would already know the gasket had blown'

Re: HELP I THINK MY HEAD GASKET MAYBE GONE

Posted: Thu Apr 05, 2018 10:44 pm
by oliver90owner
Yes, try the water test, by all means. If it sprays water out your head gasket will clearly be toast. But what about if it doesn’t? Does that mean your head gasket is good? I don’t think so. But carry on regardless....

Re: HELP I THINK MY HEAD GASKET MAYBE GONE

Posted: Thu Apr 05, 2018 11:26 pm
by myoldjalopy
oliver90owner wrote: Thu Apr 05, 2018 10:24 pm
MOJ,
Did you date my daughter?
No sir, I don't think I have had that privilege. Not unless she also thought the coal might have 'gone off' after lying for a year in the outside coal bunker :-?
But you do have to give her credit for washing out an old squeegee bottle and filling it with oil to get it down the dipstick hole!

Re: HELP I THINK MY HEAD GASKET MAYBE GONE

Posted: Fri Apr 06, 2018 7:39 am
by kennatt
if you are unsure of the gasket via the testing take it to a DECENT garage and ask them to do what is called a"sniff test" its basically testing for combustion gasses coming from the rad. Sometimes you can smell it yourself if the leakage is high. You say there was bubbles coming from rad this dosent necessarily mean gasket trouble, the usual result ,assuming hot engine and a good high rev up,not just a blip of the throttle ,is that the water is forcibly pushed out of the rad,if not and all is well with the revs held high you should see the reverse ie the level should drop,slightly as the water pump draws water round the system. The differences in comp could be caused by valve trouble, if the gasket had gone there would be little if any compression on 2/3 also the engine would be running like a tractor. good luck.