Brown sludge!!!

[Gwnapper]

Help. Im new here and looking for some help with the wifes car. She owns a mercedes a class. Oil change light came on a few weeks ago and last week engine management light. On inspection of dipstick saw oil was a light brown creamy sludge. Took to the garage who changed oil and both lights off for a week. Now engine management light back on and oil starting to go same brown sludgy again. Any ideas?

 

[markjay]

I think this is either head gasket (various ways of checking this), or the engine had too much sludge due to use of wrong type of oil in the past, and an engine flush might help (though it can be risky). Alternatively can just try another oil change and see what happens.

 

[grober]

Sounds like oil or hydraulic fluid are getting mixed with coolant. There are several places where this might happen depending on what engine/transmission/ cooling system you have. Need further investigation pronto. If large quantities of coolant are getting into the oil then its lubricating properties are reduced leading to engine wear. The usual suspects are the cylinder head gasket or the small oil filter heat exchanger found on some diesels. [ not sure if this applies to the A class diesel engine] There is a simple test for combustion gases in the coolant headspace using an exhaust gas analyser to check the CHG.

 

[rf065]

First thing I'd do is use another garage, they don't appear to have done much investigations?

Russ

 

[grumpyoldgit]

What year is the car and is it petrol or diesel?
Have you had to top the coolant up and is there any sign of oil in the header tank?
Is it used on short runs only and not reaching full operating temperature?
Does the heater blow hot or just warm? (Possible faulty thermostat)
Is there any 'mayonnaise like' sludge under/in the oil filler tube and cap?

There is at least one other thread on here regarding the same or similar problem with A Class, but I can't remember who posted it. You could try a search.
All cars produce a lot of condensation within the engine especially in cold weather and if they are used for short runs only (not reaching full operating temperature) this builds up and runs down into the sump, where it gets mixed with the oil and causes sludge. Diesel engines take a lot longer than petrol to warm up.

Found the post I referred to above. http://www.mbclub.co.uk/forums/engi...neck.html?highlight=mayonnaise+oil+filler+cap

I hope it's something along these lines and not a failed head gasket, but get it checked out.

 

[Gwnapper]

Thanks all. Further info: its an 03 petrol engine. No sludge under cap but it is on the dip stick. My wife only goes on short journeys to work, asda, etc. engine coolant looks fine. Is quite full and looks clear.

 

[shanksy]

I would second on the change of garage, that is something they really should be picking up and at the very least mentioning considering the possible implications.

 

[Benza750]

Nearly all A class do this even the newer 169 A class aswell

 

[Benza750]

They al get condensation in the filler neck which causes a build up of sludge.
It does not mean that the head gasket has gone.
The garage may of noticed it but not mentioned it as they all do it

 

[markjay]

If this is indeed a characteristic of the A Class petrol engine when used on short journeys , then I suggest that an additional interim oil service should be carried-out every six months.

 

[grober]

What year is the car and is it petrol or diesel?
Have you had to top the coolant up and is there any sign of oil in the header tank?
Is it used on short runs only and not reaching full operating temperature?
Does the heater blow hot or just warm? (Possible faulty thermostat)
Is there any 'mayonnaise like' sludge under/in the oil filler tube and cap?

There is at least one other thread on here regarding the same or similar problem with A Class, but I can't remember who posted it. You could try a search.
All cars produce a lot of condensation within the engine especially in cold weather and if they are used for short runs only (not reaching full operating temperature) this builds up and runs down into the sump, where it gets mixed with the oil and causes sludge. Diesel engines take a lot longer than petrol to warm up.

Found the post I referred to above. http://www.mbclub.co.uk/forums/engi...neck.html?highlight=mayonnaise+oil+filler+cap

I hope it's something along these lines and not a failed head gasket, but get it checked out.

The difference here is
1. its the oil that's contaminated and has become re-contaminated after a very short space of time. [ no mention of filler caps]

2. the engine light is coming on and came on again after a very short space of time

Neither of these symptoms were mentioned in the previous thread which only talks of mayonnaise on the filler cap.


Just saying -- it could be gross oil contamination by lots of sludge but seems to be more than that? hope not.

 

[Pendragon]

I had this problem last year and it was found to be condensation getting in around the filler cap area.


Keith

 

[Bacchus]

would an "italian tune up" help?