w220 oil color check help...

[dj_factor]

Hello Chaps. I have a w220 - 2000 model s320 petrol. The car has currently done 93400 miles and was last serviced at 88000 miles with a complete oil change, spark plugs, files, etc etc etc. It was service A. this is back in 2009 and now my service reminder for service b is up and I just thought to check the oil level and rest of the stuff. As I opened the oil filler cap and I saw something of a different sort, black oil color and a bit goldenish stuff. I dont know what it is or how it occured. This was after the car was stood for 6 days of non driving and after I did a 100 mile return trip, the oil filler cap was perfectly black. So i dont know wht is it. Is the engine going... Also just to mention, at the last service the oil put was Mobil 1 - 0w-40. Is it because the oil is too thin..

Your comments are always appreciated.

 

[JohnnyW202]

Either you headgasket has gone...

Or the car is driven short distances and not given time to warm up..

It's emulsified oil, caused by condensation in your rocker cover mixing with oil, if it's not driven for long distance regularly and it doesn't get upto temperature.

Otherwise if it is, could be coolant in the oil issues... Check the dipstick?

But just wipe off and change with 5W-40 soon, 10k+ is a bit long for an oil change.

I do mine every 6k-8k.

 

[dj_factor]

Thanks Johnny, Well the coolant level seems fine and the oil dipstick doesnt show any tell tell signs. dont know about the headgasket, any way to check it... short distances, well its usually we do a 10-15 miles in a week on the car, would that be to do with it. Well the next service is up and im surely going to do a 5w-40. Is 5w-40 good or 10w-40 as the car is approaching 100K miles soon...

 

[Mercsys]

Short trips without getting to running temp can give this result. If your not loosing coolant and are not seeing overheating problems, I think it is just condensation from any blow-by. I would keep an eye on it thought. Or get a “block test” done at the next service, it detects combustion gasses in the coolant tank.

You could look at a new thermostat if it is slow to get to running temperature ~92°.

 

[artyman]

If more than one trip of 10-15 miles, the engine is never going to get properly heated up, even 10-15 is debateable. Short runs are not good for an engine.

 

[JohnnyW202]

Thanks Johnny, Well the coolant level seems fine and the oil dipstick doesnt show any tell tell signs. dont know about the headgasket, any way to check it... short distances, well its usually we do a 10-15 miles in a week on the car, would that be to do with it. Well the next service is up and im surely going to do a 5w-40. Is 5w-40 good or 10w-40 as the car is approaching 100K miles soon...

10W-40 is generally a Semi-Sythetic Grade, which is more prone to breakdown and has a shorter service life, due to inferior base oils being used in the mix along with mineral oil.

5w-40 is a synthetic grade, that has a long service life and finer more refined base oils and additive pack. So it will keep your engine cleaner etc. Also keep the 5w-40 grade. Your car has hydraulic tappets and particularly in winter the grade needs to be thin when cold, i.e 5 weight when cold in order for these to operate correctly and be kept full of cold after a cold start. 100k is nothing for one of these engines, IMO. and it shouldn't be using any oil. The short journeys are definately causing your problem. Change the oil and filter, give that cap a good wipe and clean up, take when on a long journey 40+ miles, make sure the temperature guage sits midway throughout and report back. All should be well!

 

[JohnnyW202]

As said above the only way to check the head gasket hasn't been breached is to get a leakdown test done, to see if there is any chemical traces of antifreeze in your combustion cylinder, unlikely at all you'll be glad to heard as the headgasket is a big job $$$$$ £££££ especially as the chain has to come off, etc.

 

[Satch]

So that is 5400 miles in 2 years and a lot of short ish journeys.

That qualifies as "Severe Service " and really should be changing the oil more frequently because it has a finite capacity of absorb moisture if you are not getting up to full operating temperature on a frequent basis.

Would not worry about a bit of emulsion underneath the filler cap, because that is probably the coolest part of the engine and where you would expect it to form and the last place to go from after a long run.

Bung a full synthetic in and change every 12 months max. 0w 40, 5w 50, 10 w40 which meets the spec. matters not a jot unless you live in a really cold climate.

 

[dj_factor]

Thanks chaps, I must say, I have always found great help here. God bless you all. My next question is, should i get the block cylinder test or the leak test and also, I have roughly 10 litres of mobile 1 - 0w-40 oil that i bought in bulk last time, would that be any good for this time or should i put 5w-40 fully syn this time. What are your thought boys.

cheers to all

 

[JohnnyW202]

Thanks chaps, I must say, I have always found great help here. God bless you all. My next question is, should i get the block cylinder test or the leak test and also, I have roughly 10 litres of mobile 1 - 0w-40 oil that i bought in bulk last time, would that be any good for this time or should i put 5w-40 fully syn this time. What are your thought boys.

cheers to all

That Mobil 1 0W-40 would be perfect for your motor!

If you want to get a block test done for piece of mind, get one done along with a compression test to tell you how healthy your engine is. Personally I think it's just the short journeys causing this mayo effect.

 

[dj_factor]

Thanks Johnny I have booked my service for next week and will ask them to do so. Its a Merc independent garage. Just for my knowledge what happens in a block test or compression test. Thanks

 

[Mercsys]

...a block test is a simple tests to see if there is any combustion gasses from the coolant expansion tank and is quick and easy and uses a colour change in a test fluid that any escaping gasses must pass through.
The compression test is much more involved in that the cylinders are accessed either by removing a heater plug or injector, and cranking the engine with a pressure recording device replacing the injector or heater plug.
If a cracked head is suspected or a head gasket/water jacket, then the block test is a better indicator. If a cyl to cyl head gasket problem is suspected then a compression test is the way to go. As you are concerned with the possible coolant contamination of the crankcase oil then I would opt for the block test and forgo the compression test for now, unless the block test shows a problem then a compression test may be able to narrow the problem down but that scale leak would be bad enough to be showing other symptoms I would have thought.

 

[dj_factor]

Thanks Mercsys