Mayonnaise

[cwhubb]

Here's a new one on me, what is engine mayonnaise and does it damage an engine?

 

[Photon440]

It's generally a term for the creamy buildup found inside the oil filler cap or dipstick, not good news. It's from water in the oil forming an emulsion. Not necessarily a water leak or broken gasket, could be just condensation from short running times, or a thermostat not letting the engine heat up enough. A good long highway trip can often boil out the condensation and things look clean again.

Note that if water has been building up for awhile like this and the oil level is fine, it may drop down quite a bit after the water is boiled out, so check it again after the trip.

 

[coronet340]

Never heard the mayo term before. But the 2 times I've had it it was the result of a blown head gasket or warped head. Those were both 4 bangers though.

 

[Stumper]

I've seen it in oil pans before on engines with no coolant leaks. Basically from condensation that does not boil off. The combustion process does produce water and if it is not removed it will accumulate. It doesn't take much to make the emulsion and deposits you see.

 

[AMX364]

I had this on one car, it was due to living too close to work about 1/4 mile away. Changed driving habits worked.

 

[cwhubb]

weird stuff, I have never seen anything like it. does it hurt the motor? @ Stumper, I never knew the combustion process created water, I always figured the water out the tail pipe was condensation from humidity thanks I learned something today.

 

[Photon440]

Yes, combustion creates water. Gasoline is a hydrocarbon, and the hydrogen part mixes with oxygen as it burns, forming water. Almost a gallon of water is produced when burning a gallon of gas. This is what forms contrails that you see on high altitude aircraft, whether piston or jet propelled.

 

[cwhubb]

got ya, hydrogen & oxygen equal water hs chem is coming back to haunt me lol

 

[NJRR]

I used to get that in my oil-filler tube in my Tacoma pickup. I switched from dino-oil to synthetic, never got it again.

 

[Jonnyuma]

If its just on the bottom of the breather or oil filler cap then its most likely just some condensation from cooling off and/or not getting the engine hot enough for long enough to burn it off. If the oil has water in it, well...that's a different story altogether.

 

[cwhubb]

thanks guys, it coated the top of the valve covers, but it rinsed right off, nasty stuff

 

[snakeoil24]

It's Engine Cheese.

 

[bigmanjbmopar]

Did someone say Mayonnaise?

https://www.youtube.com/watch?v=vuuTS_WNw5w

 

[cwhubb]

lol

 

[Ron 73]

Never heard the mayo term before. But the 2 times I've had it it was the result of a blown head gasket or warped head. Those were both 4 bangers though.

I never myself heard the term but when i have seen it in the past i knew what it was and was never a good thing...

 

[coronet340]

thanks guys, it coated the top of the valve covers, but it rinsed right off, nasty stuff

i was thinking it might be a humidity problem but saw nm. definitely not humid there.
los alamos is a pretty cool town, expensive groceries though. lol

 

[cwhubb]

@ coronet, you got that right, it's really expensive at one point it was 28% over national average col.

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here's another question regarding coolant/water in engine... if your head gasket was leaking does that mean your engine needs a rebuild? I would think it would take a few days to a week to notice if the leak wasnt large

 

[coronet340]

@ coronet, you got that right, it's really expensive at one point it was 28% over national average col.

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here's another question regarding coolant/water in engine... if your head gasket was leaking does that mean your engine needs a rebuild? I would think it would take a few days to a week to notice if the leak wasnt large

the first car I think I just had the head gasket changed and got another 10k before I locked the engine up, but it was a beat azz car and didn't have much life left anyways.
The other engine I just had done even after really warping the head I didn't have to do any bottom end work. The valve train and head went to the shop and came out looking brand new for $450 (1 16v head off a 2.4L). There was no sludge anywhere in the block and the bottom end looked great for 140k.

If after a long drive you see it clean up then come back weeks later after no long drives I think you would be alright.
I could be wrong but a pressure test on either the cooling or cylinder should let you know if your gasket is messed up.

 

[cwhubb]

I put a new gasket on it yesterday, the valley, lifters ,cam,push rods were spotless as was the valve train

 

[MOPOWER871]

When i was running copper gaskets on a blown 440 they were a bitch to get to seal kept making milk shakes in the valve covers .finally got it squared away had to take it on a long drive and on the way home beat the **** out of it , parked it, let cool ,re torque and wa-la no more shmegma these days cometic head gaskets 0 problems no more o-ringing blocks