What engine oil for E300D Diesel 1994 W124

[SilverSaloon]

Hi

i'm planning on doing an engine oil change - probably on both my 124's - same age and engines: E300D Multivalve.

As there is plenty of Diesel W124 guys on here, anyone have any advice of the best oil to use would be?

Plus any hints on the cheapest place to get it from?

Just done the gearbox oil - general opinion was to use the genuine merc gearbox oil. Is it the same for engine oil? i run the car on a mix of veg oil and diesel so will be changing the oil probably every 4000 miles or so i expect.

i've already bought a genuine merc filter - again, not sure about whether a cheaper part would be fine, but i guess so - especially if changing regurally.

thanks

derek

 

[grober]

SHELL HELIX 10W40 diesel semisynthetic or Millers XFE 10W40 diesel semisynthetic. An appropriate HENGST filter from Euro car parts would be finehttp://www.millersoils.net/1_Millers_frame_AUTO_RETAIL.htm

 

[TonyVianoAmbiente]

I use only Mercedes genuine filters. They are not expensive and there is no point making small savings with something so important.

As for oil, I have just had the oil changed at an independent and they refilled it with Mobil 1 15W/40 for diesels. At the last service at a Mercedes dealer it was refilled with Shell Helix 10W/40. I think both are 100% synthetic but am willing to be corrected!

 

[mikevernon]

Hi Derek

Take a look at my post under the For Sale section on here. I'm selling the remains of a consignment of Shell Helix Ultra Diesel 5w40 Fully Synthetic which is ideal for your E300D. It satisfies the Mercedes 229.5 specification, but if in any doubt consult your main dealership.
I'm selling it at £3.80 per litre which is less than a third of the Shell price of £13.99 per litre. I can send it by carrier for £8.50 for any quantity up to 24 litres.

As for oil filters, I would stick to genuine Mercedes parts. I used to think that all oill filters were the same but 10 years ago I had a problem with a Golf GTi engine which lacked oil pressure. After cleaning out the sump, stripping the oil pump and replacing the con rod bearing shells the problem still remained. I mentioned the problem to a mechanic friend and the first thing he asked was whether I had used a genuine VAG oil filter. Not really expecting any difference I replaced the filter for the third time, this time with a genuine VAG one, and the problem was instantly cured! Since then I've always used the maufacturer's oil filters, whatever the vehicle.

 

[TonyVianoAmbiente]

Take a look at my post under the For Sale section on here. I'm selling the remains of a consignment of Shell Helix Ultra Diesel 5w40 Fully Synthetic which is ideal for your E300D. It satisfies the Mercedes 229.5 specification, but if in any doubt consult your main dealership.

I asked at the Mercedes dealership and also at the independent who serviced my car (same engine as Derek's) yesterday. They both advised a thicker oil than 5W for my M606 with 100,000+ miles. Otherwise I would have bought some off you, because you are offering an excellent deal here.

As for oil filters, I would stick to genuine Mercedes parts. I used to think that all oill filters were the same but 10 years ago I had a problem with a Golf GTi engine which lacked oil pressure. After cleaning out the sump, stripping the oil pump and replacing the con rod bearing shells the problem still remained. I mentioned the problem to a mechanic friend and the first thing he asked was whether I had used a genuine VAG oil filter. Not really expecting any difference I replaced the filter for the third time, this time with a genuine VAG one, and the problem was instantly cured! Since then I've always used the maufacturer's oil filters, whatever the vehicle.

The genuine VAG filters have a non-return valve to ensure that oil is delivered the instant the engine turns. That is also true of Mann and Mahle brand filters, but other brand filters listed for VAG vehicles don't have this valve. I ran only VAG vehicles until changing to my current W124 from an Audi A6. The correct choice of oil filter is very important.

 

[Number_Cruncher]

>>They both advised a thicker oil than 5W

They are both almost certainly wrong - ALL engine oil is way too *thick* when cold. Although the 5 is a lower number than the 40, the oil is way thicker at low temperatures (the numbers for cold and hot viscosity aren't directly comparable). Or, phrased another way, the 5 value is utterly irrelevant when the engine is running, and the oil is warming or warmed.

I use Fuchs Titan Super Syn 5W40 in our E300D, which I get from GSF. I also use the original MB filter, and every now and again, I change the two O rings on the centre tube in the oil filter housing.

 

[TonyVianoAmbiente]

They are both almost certainly wrong

I will make sure I consult you in future.

 

[Number_Cruncher]

>> I will make sure I consult you in future.

Ah!, shrewd fellow!

;-)

Seriously, there's a danger in being overly deferential towards both independent garages and dealership service advisors. For example, it's entirely possible that they say that 5W40 is too thin, and 10W40 is just right because they have a tank full of 10W40 to sell!

Without wishing to be derogatory, most people who work in garages and deal with customers have never spent any time studying the subject, and have probably never got further than oil manufacturer's sales bumf.

As an ex main dealer mechanic (long since out of the trade thankfully!), I can vouch for the minimal time spent considering oil during the college courses I did (1 or 2 hour long sesions seemed to cover it). I found out a little more when working on the design of a hydraulic/mechanical system for aircraft - ensuring that the system worked at -40C, when the oil looks more like butter!, was a challenge.

To see the point I'm making, find the actual viscosity values for the oil in centi stokes at different temperatures. You'll find that the cold viscosity is massive, and in all cases, oil is too thick when cold.

 

[mikevernon]

Hi Tony,

Number Cruncher is absolutely correct. It seems to be a surprisingly common misconception that modern "thinner" oils are somehow unsuitable for older engines. That is a complete fallacy.

The "5" in the 5w40 is a measure of the viscosity at 0 degrees C, and "40" is a measure of the viscosity at 100 degrees C.

A 5w oil is therefore thinner only at the crucial lower temperatures when the engine is first started and during warm-up, resulting in reduced wear and improved fuel consumption. At normal operating temperatures the second figure gives an indication of the viscosity of the oil. Therefore a 5w40 oil will behave the same as a 10w40 oil when hot, but will give the vital increased protection when cold.

Another adventage of modern fully synthetic oils is that they retain their viscosity range for a considerably longer period than older mineral oils, so an old fashioned 20w50 will offer less protection at higher temperatures than a modern 5w40, as well as causing far greater wear at low temperatures and increased fuel consumption.

So by all means use older low-tech oils in your older engines, and as long as you change it more frequently it probably won't do much harm (apart from to your fuel consumption). But please don't be under the illusion that it is somehow better for your engine because just the opposite is true.

 

[bolide]

Just bear in mind that the service interval for a W124 is 9000 miles and that this is probably the "softest" engine MB has ever produced, in that the state of tune is very low, and most never run above 4000 rpm

I'd rather spend the time and money on bushes, tyres & maintenance than on 4000-mile oil changes with fully synthetic oil

Nick Froome
www.w124.co.uk

 

[grober]

My experience of engines with a little "miles under their belt" is that the very thin 5w40 synthetic oils tend to leak slightly from any worn seals- the front crankshaft oil seal being a classic. The 10w40 semisynthetics were the "state of the art" when the engine was designed and are perfectly adequate for a non turbocharged engine like yours. If you intend to change the engine oil at more frequent intervals say 5,000 miles instead of 9,000 then there's no sense in using an expensive synthetic IMHO. If you want to extend the service interval to 10-12k miles and/or your engine is turbocharged then thats a different matter! Then you may begin to benefit from the greater stability of a fully synthetic oil. As far as filters are concerned there's little difference in price between the MB one or a good after market make like Hengst so no reason not use the proper MB one. If you have any doubts about Hengst it may help to know that the mercedes ones are made by Hengst and marked as such along with the MB logo. I have used both with no discernible difference in performance.

 

[230K]

Hi

In my 1998 E300TD i use Mobil 1 at 10,000 mile intervals regardless of what the Assyst says. If i intended to change the oil like you at every 4000 miles i wouldnt really go to the expense of fully synthetic. Bolide isnt far off the mark with what he says.

230K

 

[TonyVianoAmbiente]

My experience of engines with a little "miles under their belt" is that the very thin 5w40 synthetic oils tend to leak slightly from any worn seals- the front crankshaft oil seal being a classic.

Funny, that. The Mercedes dealer and the independent both said the same thing. They both specifically mentioned the greater likelihood of oil leaks.

Of course they were probably just trying to sell whatever oil they happened to have in stock.

 

[Ian B Walker]

I am with Grober on oils. I use either Shell Helix 10w/40 or Millers Xss 10w/40. Being semi synth they last well and provide the cover you require in conditions usually found in UK

 

[Number_Cruncher]

>>the very thin 5w40 synthetic oils

Here's the thing!, 5w40 oils aren't thin! At the operating temperature of the engine, there's little difference between the viscosity of a 5w40, a 10w40, a 15w40. When in matters, they aren't actually thin.

When cold, a 5w40 oil is still way too thick, but isn't as thick as a 15w40.

The point being that the viscosity of a 5w40 *always* lies within the range of viscosites of a 10w40 - it's the 10w40 oil that's actually more extreme. This is an example where the numbers placed on oil bottles are actually misleading - it would be far clearer if the numbers were actually viscosities in CentiStokes.

If your oil seal leaks, then, it's best to repair it. It's been my experience that you tend to get oil leaks on old engines with "miles under their belt" whatever oil you choose to pour into them.

For more, have a read of: http://members.rennlist.com/oil/Motor Oil 101.htm


In terms of the OP's question, I have no knowledge at all of running using anything other than diesel. I don't know which oils resist contamination from the different blowby products that you'll get using other fuels better than others.

 

[grober]

Here's the thing!, 5w40 oils aren't thin! At the operating temperature of the engine, there's little difference between the viscosity of a 5w40, a 10w40, a 15w40. When in matters, they aren't actually thin. I don't think anyone was disputing this??

5w40 oils aren't thin ---yes but when cold they are thinner than a 10w40!

The point being that the viscosity of a 5w40 *always* lies within the range of viscosities of a 10w40 --- true but the converse isn't true a 10w40 viscosity oil doesn't always lie in the viscosity range of a 5w40---when cold.

Why older semi-synthetics don't leak past oil seals as much as an oil with a wider viscosity range may be to do with their resistance to flow at lower temperature say as an engine gradually cools down and adjacent metal surfaces contract at different rates. Or it may be chemical in nature where the composition of modern synthetics doesn't swell the elastomers in the seals as much as the older "cruder" oils.

If your oil seal leaks, then, it's best to repair it. I agree with you 100% but there are certain instances where its difficult to achieve this. The front crankshaft oil seal is a case in point where a high mileage ( 100k+) engine may actually wear the shaft so much its almost impossible to achieve a good seal even with a new one- this can be combated by a repositioning of the seal on the shaft slightly but its not always successful.

Oil threads are always contentious. Everyone has their own ideas about what's best for their engine. The modern wide range synthetic oils are undoubtedly better products than the old mineral based oils in almost every respect its just that in certain circumstances --- older design of engine, short intervals between changes, worn seals, strained finances the older cruder semi synthetic may be the more appropriate product.

 

[SilverSaloon]

its just i'm running it on veg oil aswell so might need changing more often.

i definatly need to do the saloon though as it hasnt been done for a while and is due a service.

the estate got a full service when i bought it.

 

[TonyVianoAmbiente]

its just i'm running it on veg oil aswell so might need changing more often.

Why would it need changing more often?

 

[SilverSaloon]

Why would it need changing more often?

thats what the guys on:

http://www.vegetableoildiesel.co.uk/forum/index.php

seem to think.

some dont bother, some do.

i think it something to do with the veg getting into the engine oil or something

 

[Number_Cruncher]

>>I don't think anyone was disputing this??

Sorry Graeme, I was actually responding to your comment about the "very thin 5w40".


>>Why older semi-synthetics don't leak past oil seals as much as an oil with a wider viscosity range may be to do with their resistance to flow at lower temperature say as an engine gradually cools down and adjacent metal surfaces contract at different rates.

But, surely when the engine's cold both oils are much thicker than they are when operating, and this surely can't be the dominant mechanism?

>>Or it may be chemical in nature where the composition of modern synthetics doesn't swell the elastomers in the seals as much as the older "cruder" oils.

As a mechanism, that's more believable, but, I'm not sure if it's true, or urban myth. Is there any documented evidence of this anywhere?

>>this can be combated by a repositioning of the seal on the shaft slightly but its not always successful.

Building the shaft up with weld, and grinding back again is a good way to repair these types of seal properly.

>>Oil threads are always contentious.

Yes, that's quite true. I'm not actually much of an advocate for synthetics, and expensive oil in general. Where I jump into threads like this is where there are misconceptions about oil being repeated and re-inforced. I do tend to agree with the pragmatic point of view.

The big one that most folk get wrong is viscosity - the big problem being the numbers on the cans, who on earth thought up a system where the range of numbers on the can doesn't bear any resemblance to range of viscosity of the oil?

What proportion of people, trade included would naturally say that a 5w40 oil has a more extreme range of viscosities than a 15w40 oil? 60%? 75%?

Tony - one of the issues with running bio-fuel is how the blowby products of combustion react with the oil. It's not unknown for their to be a chemical reaction which turns the contents of the sump into jelly like gloop!