Mayonnaise - Head Gasket?

[Arnold]

Hello

My mighty MA10 is showing mayonnaise symptoms on the oil cap, which am told is a sign of head gasket failure. What other symptoms are there to look for, because although i thought she was smoking loads, that just seems to happen in the cold. With the weather being warmer recently, she's running fine & has no smoke coming out the back.

It absolutly stinks of fuel again, so think that might just be the carb or something dumping in too much fuel.

She only misfires when its cold aswell. Recently it cut out, but that i think was down to the cold / dampness & an old dizzy playing up.

Have i got anything to worry about? Apart from the mayonnaise symptoms, is there anything else i can check for.

Cheers people

 

[Low Rider]

Are you using coolant? Emulsified oil on the filler doesn't automatically mean the headgasket has gone. In cold weather it can be as simple as not driving the car for long enough to get the oil hot enough to drive out the moisture in the system. The oil system takes longer to heat up than the coolant and in conditions such as we've had lately, shorter runs can just cause a build up of condensate in the system.........not great but it can happen.

Wipe off the filler cap, give the car a nice long run over the weekend and monitor it

 

[Arnold]

Cheers Low Rider. I've got to do 90 miles later so i'l give it a wipe before i go! The majority of my journies during the week are less than a mile long, twice a day.

I do have coolant in the system, i changed it the middle of last year - probably overdue a change! It may even be a summer mixture... I may change it though and see what colour etc comes out. Hopefully not oily!

 

[Ems]

I still think your lazy. U best start cycling in the summer!!!!

 

[Arnold]

I still think your lazy. U best start cycling in the summer!!!!

Im too fat to ride a bike

 

[lewic]

Honest John website mentions K10s being prone to fuel pump failure "Fuel pump diaphragms fail, leaking neat petrol into the oil sump leading to severe engine wear and possibly even an explosion". Not that I'm trying to alarm you or anything...and I'm no expert!

 

[Arnold]

The fuel has to go through the external filter, then the carb, so how is that possible? I've never heard of K10 Fuel pumps doing that before. Mine is running rich as the exhaust fumes smell worse than a petrol station forecourt, but im hoping thats just a quick adjustment on the carb.

Anyway, i've cleaned out the mayo! there's quite a lot of it, so i'l check it after my journey and see how she looks!

 

[AMY]

If you have a lot of gunk under the cap, I would say it is probably h/g related. Have you checked the water level at the radiator and expansion tank?
I have never heard of the fuel pump failure, BUT the pump is driven by a rod that is fed engine oil to keep it lubricated, so it is possible that fuel could find it's way to the oil in the event of a leak.

 

[Fordy]

it could even be that the breather pipes on the rocker cover are blocked, and the one way valve in the inlet manifold that the big breather pipe connects onto might need a clean

 

[fox1983]

rimmer check on the underside of your collant cap is there gunk on that that is another sign of it as this was what we saw if u remember at jae on mine 2 years ago and it was a blown gasket.

 

[Arnold]

Ok, after 90 miles i removed the cap & there was no sign of gunk or anything under the cap. I did another 90 earlier without any problems but havent checked the cap as yet.

I checked under the rad cap, there's no sign of any mayo symptoms but it was a little grubby. The car isnt burning oil or water, there's still plenty in the reservoir. Its not oily or anything either, a bit dirty but thats normal isnt it? Especially as it could do with a change,

 

[Charlotte001]

mayo in the oil cap

I have to agree, just because you have a bit of white emulsion in the oil cap doesn't necessarily mean a head gasket blow.

A good way to definately tell is run the engine, undo the water cap to see if it bubbles or if you have a lot of oil on top. Expect the water to rise but what you're looking for is bubbles or smell of exhaust gas. In extreme cases you will have smoke rise off the water.

Get a compression test done check the results these will tell you forsure. If you're uncertain and you have high miles change it anyhow as the older coolant wasn't a lot of good when it came to corrosion protection

Charlotte

 

[kev_mono72]

by the sounds of things it just needed a good run to let any moisture evaporate. The misfiring is more than likely just the dizzy or coil, check dizzy for moisture and check contacts for corrosion. Might be an idea to change your oil sometime soon...

 

[Arnold]

thanks for the reply charlotte. I'l look into doing the compression test etc.

Kev, the oil was replaced not long ago, along with the Dizzy as the other one failed. The mis firing only happens when its cold & damp, could be down to incorrect timing.