Oil/filter change on a W124: how often?

[JumboBeef]

I am (hopefully) just about to buy a W124 E220 Estate 1994, and the current owner tells me the oil/filter should be changed every 9,000 miles. However, someone else told me it should be every 6,000 miles.

Who is right please?

 

[Roger Jones]

Opinions differ. I follow Honest John's advice:

http://www.honestjohn.co.uk/faq/faq.htm?id=13

Others who appear to be well informed also favour short intervals. With heavy usage -- short trips, towing, etc. -- shorter is better anyway.

 

[JumboBeef]

I agree about short changes (I change the oil in my V8 Disco every 6,000 miles) but I was just wondering what is the official oil/filter change interval on this motor?

 

[grober]

the official MB figure is every 9,000 miles. If you drive mainly motorway miles with engine nice and hot and use a good fully synthetic oil then this is fine. If your driving is mainly short journeys with the engine not fully warmed up then I would go for 5,000 miles and use a good 10w40 semi-synthetic. here's 2

 

[Number_Cruncher]

The MB figure is 9000 miles, which in my opinion is probably a little conservative - i.e., safe. Unless you're going to be using the car in an extreme way, I would stick to the MB intervals (which is exactly what I do with my E300D)

With a 15 year old W124, lubrication based engine failure is the very last of your worries.

 

[grober]

Another benefit of using a 10w40 semisynthetic is that the oil tends to stay inside the engine.

 

[Ian_C]

I would say more requent oil changes = less engine hassle in the future.

Thus, if you worry about engine wear and want to sleep at night, go for the lower figure

 

[JumboBeef]

OK, thanks. The seller currently uses semi synthetic and changes at 9,000. I'm sure I'll change that to 6,000.

Thanks again for the info.

 

[Number_Cruncher]

>>Thus, if you worry about engine wear...

But, why would one worry about engine wear? - even on these older cars, you're unlikely to have trouble that can be traced back to changing oil at 9000 rather than 6000. As an example, how often do people need advice about engine replacement and reconditioning on this site? Have a search of the forum, you won't find many!

When I took the cylinder head off my OM606 at 125,000 miles, I found the original cyclinder machining marks were still visible. In my case, after having been serviced according to the MB schedule, engine wear was truly negligible.

I would say, save your money, and use it to pay for the things that will *need* to be done on a 15 year old W124. For example, changing the gearbox oil, saving up for repairs or replacement of the engine wiring loom, brakes, suspension ball joints, coolant change, etc, etc.

I don't understand car forums - there's such a lot of hot air about engine oil changing, as if engine failure is as common today as it was in the 60s and 70s. Perhaps it's because oil changing is a DIY activity, and so all sorts of mythology have built up around it.

 

[3 phase]

Surely with new tech oils just stick to the recommended times. Unless you're doing stop start and cold runs that's what I would do. Oil science has evolved over the years, crikey an old Audi company car that I drove computed that I needed to have an oil service at 23,000 miles.

 

[bolide]

I would say, save your money, and use it to pay for the things that will *need* to be done on a 15 year old W124. For example, changing the gearbox oil, saving up for repairs or replacement of the engine wiring loom, brakes, suspension ball joints, coolant change, etc, etc.

I'd agree with that 100%. Nothing more to add

Nick Froome
www.w124.co.uk

 

[grober]

Under aggravated operating conditions an additional oil change without filter change is recommended every 7500km/4,500 miles.

Aggravated operating conditions are:

More than 50% short distance driving (less than 8km/5miles each time) in conjunction with a coolant temperature below 80c. This is particularly critical with low exterior temperatures.

More than 50% driving in low gears in conjunction with high engine load in (driving in mountains, trailer operation etc.)

verbatim quote from my Mercedes Maintenance Booklet. I feel my suggestion is good compromise between what some folks ( the 9k guys) and the Mercedes "official line" advises perhaps printed before the modern fully synthetic oils were routinely in use?
The "cost factor" is dealt with by using the cheaper 10w40 semi-synthetic e.g. 5 litres FUCHS XTR 10W40 at £16-19 MB 229.1 rather than a fully synthetic say 4 litres FUCHS TITAN SUPERSYN 5W40 at £ 27-86 MB 229.3
so the oil costs roughly the same.-one change V two changes
There is the hassle of changing it of course and the disposal of the old oil which may influence which regime to go for.

 

[Number_Cruncher]

>>perhaps printed before the modern fully synthetic oils were routinely in use?

Yes, I think you're right. It is the general advance in oil technology since W124s were new vehicles that leads me to say that the 9000 mile standard interval as then advised by MB is now well and truly on the safe side, and that unless severe conditions apply, changing any earlier is completely unecessary.

Some engines were carried over into W210s essentially unchanged in form - what were the service intervals for those engines?

 

[JumboBeef]

I don't understand car forums - there's such a lot of hot air about engine oil changing, as if engine failure is as common today as it was in the 60s and 70s. Perhaps it's because oil changing is a DIY activity, and so all sorts of mythology have built up around it.

I asked about oil changes because I currently run two Land Rover V8s, and I have owned other V8's in the past.

These V8s can suffer from oil starvation at the top of the engine and with these engines, oil changes at 6,000 max is very important (I've just changed the oil in my Disco last weekend, at 5,500 miles).

V8 engines are very expensive and oil is very cheap, so I would rather err on the side of caution and change early. Having said that, I've never had a Merc before so that is why I was asking in the first place!

 

[grober]

>>perhaps printed before the modern fully synthetic oils were routinely in use?

Yes, I think you're right. It is the general advance in oil technology since W124s were new vehicles that leads me to say that the 9000 mile standard interval as then advised by MB is now well and truly on the safe side, and that unless severe conditions apply, changing any earlier is completely unecessary.

Some engines were carried over into W210s essentially unchanged in form - what were the service intervals for those engines?

Can't answer that one since I havn't got access to official MB literature for the W210 and my advice was influenced to a certain extent by the original posters model a '94 E220 the same as my own car. I'm sure you are correct tho. It is interesting however that Mercedes have recently moved away from the variable service interval oil change back to fixed mileage/time for their latest vehicles-I think its 10,000 miles/1year but perhaps owners of new MB models could confirm this? I know Mercedes had huge problems in the 90's in the USA when they first introduced extended service intervals on their cars because dealers/owners tried to run their engines with these extended oil changes using what they lovingly termed " dyno-oil" i.e. old fashioned multigrade mineral oil instead of the newer long life synthetics. The result was a lot of wrecked engines!
I suppose what i am saying is a 9,000 mile oil change interval on a good fully synthetic oil is well within the boundaries of safety and will cope with whatever type of motoring you throw at it. A 9,000 mile oil change interval on a 10w40 semi-synthetic oil may just be reaching a marginal performance state under arduous operating conditions. The engine's not going to blow up or anything but there might be a bit of extra bore wear or the narrower oil passages or hydraulic tappets start getting gummed up with sludge. Problems that will only become obvious in the longer term.

 

[Number_Cruncher]

>>Problems that will only become obvious in the longer term.

But, we're already talking about 15 year old cars (and some W124s, over 20 years), I would say we're well into "long term" territory already!

A mechanic I used to work with years ago now works at a Vauxhall dealership. He says that the trouble they've had with longlife is where people use the wrong oil, and if people stick to the longlife regime properly, the cars are fine.

 

[Uberwagon]

The biggest help you can do to an old engine is give it a good thrash every so often in my opinion.

Dave!