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MG MGF Technical - Mayo on dipstick but not head gasket?!

Ok, so I have got the dreaded mayo on dipstick. Obvious thoughts were head gasket but I was losing no coolant. Garage pressure tested or what ever they do and confirmed there were no leaks. Assumed it was condensation. All oil was changed - however it has appeared again-quite a lot on the dipstick - still not losing any coolant and there is none on the filler cap.
Don't really do short journeys but I noticed the other morning before the car was used that there was a lot of condensation on the dipstick when I pulled it out.
Has anyone come across this before? Do you think that the dipstick/dipstick cover could be not sealed properly???
Any help appreciated.
Rob

If we're talking quite significant quantities of mayo, rather than a few spots on the dip stick that disappears when the engine warms through, then I am afraid that we are looking at a head gasket failure - probably somewhere around cylinder 1 and 2: the elastomeric seal has probably failed. :o(
Rob Bell

Rob

The burning of 40 gallons of fuel probably produces 40 gallons of water Although most of the water goes out the exhaust as a gas, some ends up in the engine crankcase as byproducts of combustion.

Your engine is a distillery in which water, combustion byproducts are added into a oil bath; agitate and aerate with the crankshaft and other rotating parts; heat until the more volatile products, principally water, vaporizes into a gas and flows out via breather into the cooler atmosphere.

Oil normally requires 20mins driving to come up to temperature and condensation does occur within engine re fluctuations of night and day temps if car not used.

Paul




Paul

Does you temp gauge rise to the one notch below middle after about 1 mile and then stay rock solid in that position irrelevent to how fast you are driving ?
Will Munns

Paul, a sump full of mayo isn't going to be the result of condensation! ;o)
Rob Bell

Rob,

Yes it is! as well as poss HGF. Although as its so called summer I would have more concern and would therefore check if a breathing problem is causing water accumulation and emulsification.

Paul
Paul

Have to say I've experienced this aswell. Not on an F, but on a Moto Guzzi I used to have for commuting. Loads of mayo, and was down to blocked breathers. Likelihood with F's though always seems to point to a head gasket :(

Alex T

Not ever heard of crankcase breathing problems causing condensation to this extent - but I can't say I don't believe you Paul.
Rob Bell

Rob,

Just trying to offer a glimmer of hope.

Certainly cold winter running can produce substantial amounts of Mayo, however if the engine is prevented from getting rid of excess water then it will just build up and is not temperature related. If anti feeze is in oil then immediate action is needed as it will kill the internals.

Paul
Paul

Thanks for all the feedback. Seems to get mayo high up on the dipstick and quite a lot of it. Was surprised to see the condensation though!!
Have to to admit that I was expecting to see it on the filler cap as well.
I guess I just need to keep an eye on it. Certainly do not seem to be losing any coolant.
Rob

Rob - you didn't answer the question on temp
Will Munns

Hi,
Temp gauge does just as you said. Rises steadly then just stays constant regardless of driving conditions.
Rob

How are you with a spanner?

If you are up to removing the engine cover then I'll give you further clues.
Will Munns

Yep,
No worries with a basic spanner. Replaced rear shocks and changed the steering column are the most I've done on it!!
What's the advice?
Thanks
Rob

OK, if you've changed shocks then this will be a walk in the park!

Remove the carpet and underlay from the engine cover

With a 10mm spanner remove all (12?) 10mm bolts from the engine cover and slide it forwards then hinge the back up to pull it out - watch your fingers on the sharp bits of trim!

With the cover removed you should have a clear view of the top of the engine.

At the back of the engine (as oriented in the car) in the centre of the cam cover there are two lugs, on these lugs should be two pipes, one should go directly to the inlet manifold, the other is longer and should end up on the throttle body.

Remove the pipes, they should be push fit and do not need hose clamps

Run water thru the pipes to check they are clear

poke a small screwdriver thru the holes into the manifold and into the throttle, check for gunge, if there is gunge then scoop it out.

Do not poke the engine

refit the pipes

Start the engine

remove the pipe to the throttle body, the engine might breifly pick up and then fall back - this is to be expected. put your thumb over the pipe, you should feel it being sucked on.

If you are unsure, or even if you're not you may want to open the cam cover.

-remove the spark plug leads from the spark plugs,
-note where they go, loosly block the spark plug holes -with tissue to prevent you dropping things in them!
-
-Starting at the ends remove the bolts with a 8mm
-spanner, undo 2 bolts, swap ends working inwards. dont
-forget bolts in the centre
-
-With all bolts removed pull the cam cover free
-
-The cam cover gasket is a plastic sheet, it might be
-pressed onto the cam cover, pull it off
-
-Do not be surprised to see plenty of white goo :-(
-
-Looking into the cam cover you should see two "brillo
-pads" one for each pipe from earlier, pull them out
-
-Soak in petrol/WD40/thinner of your choice & aggitate
-them to free any gunk
-
-Press them back into place
-refit gasket, it says which way is up
-
-Working from the centre outwardsfit the 8mm bolts
-thumb tight
-
-using the same pattern tighten the 8mm bolts
- BUT NO TIGHTER THAN YOU WOULD THINK "REASONABLE" IF
- YOU WERE USING A 8MM SPANNER **WRENCHES ARE
- DECEPTIVE**

refit is the process in reverse, take care with the 10mm bolts also, they loose their threads easily.
Will Munns

This thread was discussed between 06/07/2005 and 12/07/2005

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