Best oil viscosity for OM612 after 100k miles?

[Zarniwoop]

Hi,

Hope this isn't a daft question, but I see from the handbook that there is more than one viscosity of oil suitable for my CLK 270 CDI. I happen to have 10 litres of 5w30 that meets the correct M-B spec, but it's in the back of my mind that maybe after 100k miles I should be using a higher viscosity.

TBH, I'm used to running much older cars than this, and maybe modern engines don't suffer the same levels of wear.

Just wondered what the received wisdom is on this? Should I try the 5w30 and just see if it uses oil? Would there be any risk to the turbo?

By the way, is it true that there is no physical dipstick? Is it possible to add one. I'm sure the sensor is amazing, but I feel you can't really beat seeing the actual oil level sometimes.

Thanks in advance!

 

[sonic]

I am sure my 270 used Moblie 1 5w30, & I sold it with 115K on the clock. It never used oil.

 

[mioba]

Yep daft question.

 

[oigle]

Yep daft question.

Don'tbe nasty to a new member. Simple question. Really viscosity is relevant to climate. In UK, I'm sure 5W/30 is appropriate. In Oz, I use 15W/40. Horses for courses. An MB engine with moderate mileage would be fine on the lower viscosity suggested in UK.

 

[Gazwould]

Never understood the climate thing as engine temperature is regulated , seems like an air cooled engine theme .

A 15W40 tends to be a semi synthetic so will be missing out on the top two oil basestocks.

Strangely these two real synthetics top groups take the higher temperatures best.

 

[Zarniwoop]

Yep daft question.

Well apologies for that then.

As you can see below, the handbook suggests either viscosity should be OK for the temperature range we experience in the UK. However, I know from experience (I built the engine in one of my other cars) that with older engine designs it's quite normal to move to the slightly higher viscosity oil as an engine starts to become a bit 'baggy', as it were.

I guess my question was whether the 5w30 I already have would be acceptable, even though the engine has done 100k miles. Based on the experience of @sonic it sounds like it should be fine, which is good news as I had no use for the oil otherwise!

Thanks all

 

[oigle]

Never understood the climate thing as engine temperature is regulated , seems like an air cooled engine theme .

A 15W40 tends to be a semi synthetic so will be missing out on the top two oil basestocks.

Strangely these two real synthetics top groups take the higher temperatures best.

It's not so much the controlled temperature but the starting temp. UK can suffer from very cold temps whereas Oz does not. The need for quick initial circulation is paramount for preventing wear.
With running temps, yes the water temp is controlled by thermostat which keeps the oil at a suitable temp once warmed up. However, with high summer temps here and harsh usage such as towing, the cooling system often struggles to cope. Oils regularly run at temps above 100°C in those conditions. A higher viscosity oil helps in these conditions.
My car is a 2003 ML270 and is quite happy on a diet of semisyn. TBH, synthetic oils are a bit of a con in our climate. They do little outside of creating a high viscosity range, concentrating on the lower range. They have a higher additive level which can allow for extended oil changes but I prefer to change the oil every 10000KM. Works out about the same cost and I have fresh oil more often.

 

[mioba]

I have always stuck with what my came with and rexomended at the time.
My W124 was only fed mobil 1 0w40 and after years before she succumbed to too much rust the engine was still clear as a whistle and it never used a drop and done 114k.
My W220 uses only mobil 1 0w40 turbo diesel, after 18 years it doesnt use a drop and on 78k
My W251 uses shell helix 5w30 and is on 60k now.
My W205 also shell helix and is on a poultry 22k.
Merc engines are pretty solid and I dont think they loosen to an extent that they need a different oil with age. The engine will outlast the car.

 

[Zarniwoop]

Just going back to my earlier question: is it true that there is no dipstick on the 270 CDI engine? And if not, can you fit one?

Remember seeing a removable red cap that didn't seem to do anything in the back right (as you look at it) of the engine bay. Wondered if that was a dipstick tube ...

 

[Mark A]

The red cap is most likely the gearbox filler tube.

 

[sonic]

Just going back to my earlier question: is it true that there is no dipstick on the 270 CDI engine? And if not, can you fit one?

Remember seeing a removable red cap that didn't seem to do anything in the back right (as you look at it) of the engine bay. Wondered if that was a dipstick tube ...

Its a long time ago but I am sure you could check the engine oil level on the 270, was it on the dashboard display?

 

[Zarniwoop]

Its a long time ago but I am sure you could check the engine oil level on the 270, was it on the dashboard display?

That's right, there's a section on the dash menu to show you oil level. But, being a luddite, I would get considerable reassurance from being able to see the actual oil on a real dipstick!

In all seriousness, I'm partly asking just because I've never had an engine that didn't have a physical dipstick before. It bothered me slightly when I bought the car that I had to trust the seller about the frequency of oil changes, and wasn't able to see a 'sample' of oil to see how clean (or otherwise) it was.

 

[oigle]

270 engine in ML certainly had a dipstick. Presuming engine is similar to yours, there should be a place where the dipstick was situated. Maybe just plugged off? If so, should be able to buy a dipstick and tube and install it of you wish.

 

[Zarniwoop]

@oigle I don't suppose you could give me some directions as to where it's sited on the engine, could you? Would quite like to see if I can find some sort of blanked off or plugged port if I can.

 

[mercman111]

at the back as your looking at the engine from the front on the right under the plastic cover

 

[mercman111]

you will need to buy a dipstick but dont leave it in

 

[Taffy7hfa]

Engine oil dipstick .ML 270

 

[Zarniwoop]

you will need to buy a dipstick but dont leave it in

Can I ask why?

 

[V6Matty]

Can I ask why?

They are longer and hang out of the dipstick tube and can fowl, the 612 in the 209 was a bit strange like that, I always wondered why they didn’t fit the 647 to it like they did the 211 had, much more refined engine in 5 pot guise

 

[JBell]

Surely this will be perfect

20L Genuine Mercedes-Benz 5W30 Fully Synthetic Engine Oil Low Ash - MB229.52 7427011890988 | eBay

Optimises engine performance through reduced internal friction. Good cold starting performance, low oil consumption and minimised exhaust emissions. Minimises engine wear resulting in optimal engine service life.

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