milky oil and maybe too much oil ?..

[simbad]

2 things worrying me.

1. i checked the oil and it was a little low about 1/3 on min/max- topped it up.
read manual last night and it said that dipstick checks should be 10mins stopping after normal running temp.
not sure i had done that, so i ran engine warm today and checked. seemed to be about 3 to 4 mm higher than the Max line.

is that a problem, i heard to much oil can cause probs?

2. Big worry. opened the oil filler cap and there was a very small amount of milky/oily slightly white, slightly sludgy oil on the inside of the cap. only a little and a small wipe with a tissue it was gone. although i think i noticed the same about 3/4 weeks ago when i checked the oil, but in between checked once and nothing.

i remember from somewhere this meaning water getting in the engine and causing big probs?

Advice please?

Should i take the car for an oil change to rectify the levels. and any recommendation on type of oil.

Car is yr 2000 CLK 55 AMG

 

[Stulc]

To much oil is as bad as to little as you know....to much can blow seals ect, I had to much in mine when I got it but got some out pretty dam quick.

I would have it between min/max but dont let go above max......milky/oily sludge on the cap could be condensation as I also had, and was due to mine sitting for a couple of month's on a forecourt and just the odd (very odd) short run which as we all know isn't good at all.

I would get you car for a good long run (after taking some out....or changing it) then check the cap and I'm quite sure the sludge will have all but gone. Also check your expansion tank for sign's of oil in the water, put your finger in and look to see if there's any traces of oil if not then it's probably as stated above.

As for what type....I would just use a good 5-10/40 and regular changes.....I'll be changing mine every 6 month's which probably is more than most, but thats me.

 

[simbad]

when to read.

so when is the most accurate time to take a reading on the stick?
and is it 1L from min to max?

 

[Stulc]

I know they say 10 min's....I'd wait about 5, but it's swing's n roundabout's...


I think it's 2 ltr's between min/max...but it tell that also in the manual.

 

[simbad]

I think it's 2 ltr's between min/max...but it tell that also in the manual.

Wierd, i thought it would bbe i just checked back and nothing in the manual on the amount from min to max- i had always thought this was just 1L.

 

[television]

The worst that can happen is that you can damage the CAT with too much oil
when it is warm, by the time that you have turned off the car, got out and opened the bonnet and pulled the stick, wiped it and put it back it is near enough. The car has to be on level ground in all ways. 2 to 3 mm I would not worry to much. Might not be a bad idea to check it when cold when all of the journals have drained, if it goes over 3 mm I would take a little out.

Most fluids in the car take in moisture over a period of time, more so when standing, these however soon evaperate when the car is used.

Malcolm

 

[tom7035]

Simbad. Don 't become paranoid about oil level. Too much yes can be harmful, but let it settle down to somewhere between the marks.

 

[Stulc]

It's ok saying to get parnanoid over to much.....you were all warning me of the danger's of to much eg blowing seals ect. I allready knew that but just didnt know how much over in the C280 would do any damage.

I know just a bit over eg maybe 1/2 ltr or so wont do much, but a ltr + can/does, yes it will eat the cat too.

 

[simmo300e]

too much oil will eat the cat?? I don't know where that assumption comes from but if you've got to that stage, replacing the catalytic converter is the least of your worries.

i'd be concerned about that milky sludge, could be condensation in the rocker head but could also be a blown head gasket.

use good oil and change it often, saves a lot of worry in the long run.

 

[Stulc]

i'd be concerned about that milky sludge, could be condensation in the rocker head but could also be a blown head gasket.

In my case it's not.....it was just condensation.

 

[cubicincubi]

Too much oil is dangerous for the internals - oil on the cap isnt caused by a sitting vehicle.

Too much Oil

too much oil causes oil to be thrown off the crank up onto the pistons and the bores, this gets past the rings into the combustion area, it's known as 'pumping', it wears the rings and bore causing increased blow by, carbon deposits on injectors, valves and the combustion area in general, the ecu corrects as emissions soar.

With too much oil as well as increased crankcase pressure your pcv will be working overtime, burning even more oil, oil deposits and cooked sludge may block or limit the pcv operation causing further increased crankcase pressure, causing seals to wear and bore/ring wear. In addition this can cause overheating and warping in the head and leads to head gasket seep and eventual cylinder head or bore wall fractures, all dependant on engine management spec.

This of course is in relation to how far the car is driven with too much oil, the rpm values, temperatures and other basic factors.

Mayo on the oil cap.

I personally would not expect to see ANY white on underside of the oil cap on a 2000 merc unless it has been driving with the intake into heavy rain or water spray, or through a dense fog for example. This is not caused imho by moisture entering an engine left sitting.

Why?

Dew or frost forms on objects that have cooled to less than the dew point or frost point (the point at which air is saturated with water), respectively.

Objects near the ground will cool more rapidly at night than the air itself, which is somewhat transparent to terrestrial radiation (heat energy leaving the ground). So dew or frost will normally occur before a fog will form.

The supply of water for dew or frost normally comes from water in the air, although excess water in the air can come from the soil and/or in plant leaves, particularly after a day of rain. Evaporation of water from the ground continues even at night and results in a shallow, more humid layer of air near the ground, resulting in some soaking dews on grass at times.

The only route for moisture into the crankcase is past the rings, valves via the manifolds or past the PCV if it is two way or moisture allready in the crankcase from previous high moisture content blow by, which is mixed and will rise to the head and stick to the surfaces. I dont believe that ambient moisture can enter a sitting engine and mix with the crankcase vapour to then condense and form a mayo on in the head/cam cover.

This of course is in relation to how far the car is driven with too much oil, the rpm values, temperatures and other basic factors.


White mayo is imho the result of crankcase vapour with mixed moisture collecting in the head after running due to ingress in airflow or gasket issues. It collects in the cam cover as its the first place to cool after engine shut down.

This is a pic of what is pumped through the pcv and back to your intake route though this particular test used a catch can routed from the pcv with the intake route blocked. It also acts as a condensation catch can - it's minus the evaporative loss which happens during normal operating temperatures, vented through a filter (would normally be burned in the intake stroke), see what solids are left and what h20 is present, it's hard to see the quantity but this is about 250ml. This is about 1000 miles worth of crud;

The coolant was spotless. The mixed moisture and crankcase blow by vapour isnt mayo, though it is mixed to a degree, though not through condenstion contact but through mixing while moving in vapour form, most of the settled condensation is seperate from the sludge.

So, if I was to answer the initial question simply, I would say change the oil and filter, too much oil can cause damage but is dependant on the conditions of use whilst too much oil is present, and mayo in the cam cover is either a failing head gasket, or water ingress in the intake airflow whilst the vehicle is moving, condesning with the oil vapour on the first to cool area on shutdown. Time between use should not be a factor.

opinions welcome.

 

[shirubaby]

so condensation can lead to a milky substance within the camsharft area?

 

[cubicincubi]

i'm suggesting that condensation that developes in an engine which is not running and sits for a while will not make a mayo. it is ingested water in the airstream through the intake or leaky gasket that leaves the milky substance once the engine cools. it also rises to the top of the rad, coolant resevoir or expansion tank if it is a gasket or water channel fracture.

the crankcase vapours and oil are pumped through the engine to lube the head - cams - the oil drains away back to the sump, the vapours under positive pressure exit via the PCV valve (positive crankcase ventilation) commonly called 'breather' to the inlet route and these gases/vapours are burned in the combustion process.

positive pressure is the result of cylinder blow by which is present on all engines. without a breather or vent the seals would burst and the oil would be forced out under pressure.

on engine shut down these vapours with a moisture content rise to the head through oil channells as the head cools and collects on the top of the inside of the cam cover/rocker cover and inside surface of oil cap as these are the first areas to cool. condensation sitting in a cold stationary vehicles can't mix with the oil and cause mayo.

 

[Charlotte001]

Milky white in the oil is commonly head gasket failure. It is a mixture of the combustion gasses and water mixing with the oil to form a type of emulsion. although it could just be condensation somewhere in the system such as a cracked water jacket.

Charlotte

 

[Stulc]

Well all I can say is that the "milky" oil that was on my cap when I got it has gone!, I'm using it regular and a few long hauls thrown in for good messure and all seem's fine.

I thought I had a photo handy but it's in the camera and the batterie's are done, but if I remember I'll send a pic of what my cap used to look like.

 

[big x]

It seems modern extended oil drain times and owners not using high RPM's on larger engine cars may be the cause of light colored emulsion.I looked at several 3 to 4 year old BMW 5-series at a car supermarket and all had it on the underside of the filler cap. All where FSH but low mileage cars can go 2 years without oil changes or up to 18k.Does the combustion process itself produce vapour that thins the oil and condenses ?

adam