10 replies to this topic

[josh austin mini city e 82]

Hi, think my head gasket has gone, got a few symptoms. Emulsified oil built up round the oil filler cap, there is a bit if white smoke coming from the exhaust but not much. Is there anything else it could be before I go taking the head off ? Don't want to do it if there is no need the coolant level doesn't seem to have gone down though which has confused me a little. I asked a friend he said it could be condensation from short journeys, but I have it a good run the other day (probably shouldn't have encase it is the headgasket I know) but there is still a build up of that 'Mayo' like stuff in the filler cap. I noticed it last week after I topped my oil up. As with a lot of minis mine has a very slow oil leak. I did use a different type of oil but I don't see how that would cause this 'mayo' :-( also it doesn't seem to overheat ...
Any help or advice on this is much appreciated !
Thanks
Josh

[creakyjaws5533]

Get a compression test to see if any cyclinders have lost compression if they have most likely the head gasket has gone

[josh austin mini city e 82]

Iv got one ill check them and get back to you

[lewBlew]

As you say mayo may be caused by condensation build up after lots of short journeys (esp. in the cold) so don't base your theory on just that! White smoke out of the exhaust can be due to various things, some bad some harmless. So again, don't worry too much.

 

If a head gasket had totally 'gone' the engine would by dying, overheating, steam everywhere and boiling noises, etc.

 

Don't panic! Get it tested properly before you do.

[josh austin mini city e 82]

As you say mayo may be caused by condensation build up after lots of short journeys (esp. in the cold) so don't base your theory on just that! White smoke out of the exhaust can be due to various things, some bad some harmless. So again, don't worry too much.
 
If a head gasket had totally 'gone' the engine would by dying, overheating, steam everywhere and boiling noises, etc.
 
Don't panic! Get it tested properly before you do.

Thanks for the reply, wouldn't a a good long run clear the 'mayo' out though ? I'll get it compression tested later on and see what's what

[sonikk4]

To get rid of mayo build up you need to clean it all out thoroughly including the breather as well. One trip will not do much but several long journeys will.

 

The compression test may not show anything but the thing to look for is rough running, coolant level dropping and water in the oil. My clubby has mayo but he was only used for short journeys to start with. A really thorough cleanup of everything, fresh oil and several good runs later sorted that out.

[mister bridger]

Head gasket went on mine recently and the only symptoms were rough running and lack of power. No leaks, mayo or steam. Compression test showed a lack of compression on cylinders 3 and 4 and sure enough the gasket had gone between these two

[JackF]

I have mayo in my rocker quite often. Cold air coupled with the alloy rocker cover + a few short trips causes this. No loss of coolant, no boiling, no loss of power and a good even compression. I've given up worrying about mine. Check your compression.

[Cooperman]

The HG usually fails in one of three modes.

The first is a failure of the fire rings between 2 & 3 which causes lack of power but no loss of coolant.

The second is a failure from cylinder bore to a water hole. This throws white steam out of the exhaust pipe.

The third is failure where an oil hole is part of the failure and this results in oil in the water and water (emulsified) in the water (=mayo in the rocker cover).

You can, of course, get a combination of these.

If in any doubt just whip the head off and change the gasket as if it fails on a journey it's a nuisance. After all it's a quick & cheap job to do on a Mini, especially if you have used 5/16" x 1.25" long bolts to fit the manifolds to the head as that saves removing the exhaust manifold or undoing the carb connections (maybe that's 'tip of the week').

[ethana]

Head gasket job on the mini is very straight forward. And if you suspect it's gone your probably right. Are you losing coolant?
The most effective method to determine gasket is a sniff test. They are relatively inexpensive and will defiantly diagnose the problem. The kit contains a blue dye which when exposed to products of combustion turn the dye green/yellow. Just offer the tool into the neck of the rad and run the car. Squeeze the bellow valve repeatedly to encourage the vapours into the dye.

[Cooperman]

Head gasket job on the mini is very straight forward. And if you suspect it's gone your probably right. Are you losing coolant?
The most effective method to determine gasket is a sniff test. They are relatively inexpensive and will defiantly diagnose the problem. The kit contains a blue dye which when exposed to products of combustion turn the dye green/yellow. Just offer the tool into the neck of the rad and run the car. Squeeze the bellow valve repeatedly to encourage the vapours into the dye.

This is a great way to test whether the HG has failed between combustion and water, but it won't tell you whether it has failed between 2 & 3 across the fire rings. A compression test will diagnose this however.