Oil for a '74 Mercedes 450 SL

[Tommiee]

I'm just wondering what oil to use in my '74 450SL running on LPG.

Car runs on 10W40 right now, just wanted to know if this is the right viscosity for this engine.

On the mercedes forums they mostly use 10w40, but my mind keeps saying 15w40 or 15w50.

Can get Total oil for very low prices, so that will be my preference.
Should I stick with dino oil? don't want it to leak more than it does now ( not much, but a little from the crankshaft seal )


Mileage is 197.000 miles ( yes, it's imported from california to Holland )

Thank you guys for your opinions.

 

[EddieCairns]

If it has done 200,000 miles on 10W/40 and has no lube problems and you are worrying it appears you need to get out more.

Would you be less worried if it had done 250,00 miles and be happier then to keep it on that weight of oil or would you be looking for a longer proving mileage.

eddie

 

[Tommiee]

The lubrication is fine i guess, but it uses some oil,

Valve seals i guess, when lifting the throttle at higer speeds i can sometimes see some blue smoke, and smell it.

Don't know if another type of oil or viscosity is going to help here?

Lubrication is the most important, i'd rather fill a quart of oil every 1500 miles, than missing lubrication.

 

[mahansm]

Your oil usage is almost certainly valve stem seals, caused by worn valve guides. That engine series puts a fair side load on the valve stems. Guides typically last about 170,000 miles.
Replacing the seals is a very short term fix, as without the new guides the seals will not last.

I've seen engines of this type in the shop for their third set of guides (500,000 miles). Internal engine parts clean, original hone marks still visible on cylinder walls.

As long as pressure is good, 15W40, 10W40, or the 0W40 oils should be good. 20W50 would work for a summer grade.

 

[Tommiee]

Valve guides was the word i am looking for, my english isn't perfect.

Going to get the valve guides replaced within a short term.

Bodywork is completely finished now, so the last bits are the engine, wich is running superb, but only the valve guide issue is something that has to be fixed.


This is her

 

[Kool1]

That is a beautiful car. I believe Bruce Lee had a similar car only in white.

 

[Tommiee]

Thank you Kool1.

 

[Turk]

Beautiful.

 

[Tommiee]

Last year i got the dash leathered ( how you say it?)

Made the wooden parts myself, with a very very smal saw( dont know the translation.. )

 

[Tommiee]

And the seats ofcourse!

 

[05LGTLtd]

Very nice, indeed...

 

[Tommiee]

Thank you very much!

 

[fdcg27]

Nice car.
I've always liked this generation of SL.
One of the classiest looks of the modern era.
I'd say that a 10W-40 would be fine for this engine in your climate.
FWIU, these iron Mercedes V-8s are long-lived and unfussy.
Can you get Valvoline Maxlife in Holland?
It might be worth a try for your rear main seep.
Much cheaper and much easier than removing the tranny, and IIRC, there are some Mercedes cars of around that era in which the automatic cannot be separated from the engine while installed in the car. Both have to be hauled out as a unit.
That would be a major pain and/or expense.

 

[spk2000]

Very nice!!!

 

[Doug Hillary]

Hi,
Tommiee - I agree with the cmments about seals and guides

Once done you would be well advised to use a 5W-40 C?/S? HDEO (Delvac, Delo, Rotella/Rimula) if you want to change from your 10W-40. These engine families always performed well on HD lubricants

My first Benz was a 230SL - in 1970 - I should never have sold it!!

 

[sprintman]

Originally Posted By: Doug Hillary
Hi,
Tommiee - I agree with the cmments about seals and guides

Once done you would be well advised to use a 5W-40 C?/S? HDEO (Delvac, Delo, Rotella/Rimula) if you want to change from your 10W-40. These engine families always performed well on HD lubricants

My first Benz was a 230SL - in 1970 - I should never have sold it!!


Afternoon Doug!!

 

[Doug Hillary]

Hi,
sprintman - good to see you around again- stay with us. Is Julia keeping you in order.......

 

[gregoron]

Lovely car. Just goes to show that they don't make them like they used to anymore. Cars today - not just MB's - have become commoditized. Yes, they're safer and more efficient, but they're sold as packaged electronic gadgets than the driver's car back then.

 

[sprintman]

Originally Posted By: Doug Hillary
Hi,
sprintman - good to see you around again- stay with us. Is Julia keeping you in order.......


Yep, but Kev would be better. You must update me on the new version(s) of Delvac 1 soon, I'm outa touch.

 

[Tommiee]

Planning to change the oil this winter. Car will not be driven during winter period. It's a garage queen and drives between 500/750 miles a year.

Still not sure what oil to use. What kind of specs do I need?
Does it need a higher ZDDP oil?

Will 5w40 be good enough or should i keep using 10W40?

There's a 'cheap shop' here that sells oil called Techno. Opinions are mixed about this oil but it costs like 10 dollars for 4 Litres 10w40

normal prices here at car parts shops are ore like 15 dollars for
ONE litre..