[BowMan]

Originally Posted by Jeroen

That would be interesting.
Why even bother?

Jeroen

You mean with high ZDDP oil (let us forget the synthetic vs mineral debate)?

The newer oil specifications adopted worldwide call for less ZDDP as it is detrimental to catalytic converters. Mineral Oil which was available a few decades ago did not have these limitations. If you run low ZDDP oil in some classic car engines you might end up with premature wear on some surfaces.

[Jeroen]

Originally Posted by BowMan

You mean with high ZDDP oil (let us forget the synthetic vs mineral debate)?

The newer oil specifications adopted worldwide call for less ZDDP as it is detrimental to catalytic converters. Mineral Oil which was available a few decades ago did not have these limitations. If you run low ZDDP oil in some classic car engines you might end up with premature wear on some surfaces.

The key word here is some classic car engines. The jury is still out on that.

Truth is that the ZDDP debate is not really a topic of discussion on classic cars forums here in Europe. Nothing like for instance the removal of lead in fuel, which was a big thing.

But there are already parties advertising and bringing products to the market, be in special oils, or special additives to counter any negative effects of low ZDDP.

However, we do know that the average classic car in Europe runs about 16-1800 km a year. Do you really need to bother. In fact the same is true for replacing valve/valve seat on a classic so it can run on lead free. If you do very low mileage , what is the point?

What is also interesting to know, what would wear, if it is mainly the tappet, rather than the cam, on most cars, when push comes to shove, easy inexpensive replacement. Not sure how the business case would work out. Again, all down to how quickly stuff wears, or not.

Maybe a synthetic oil can be a good replacement for a mineral oil low on ZDDP?

I use run of the mill mineral oil on my W123. It has done about 45.000 km since I owned it. Minimal wear on the cams, I check the valve clearance religiously every year. Nothing out of the ordinary yet. That is no guarantee other similar engines would have no problems too.

But this kind of wear is easily checked and monitored.

If I call Mercedes Service centre for an oil recommendation today for my W123 they will come up with all the usual “modern” mineral oil. Nothing special.

Jeroen

[zalaps]

Originally Posted by BowMan

Some days the weather is just perfect and I will sign off now and let the pictures do the talking

How on the earth I missed this thread! Drooling! Someday would like to check out in person. Right now can't get over these pictures!
GIFT City & W123 are a contrast that jells surprisingly well!

[BowMan]

Originally Posted by Jeroen

Maybe a synthetic oil can be a good replacement for a mineral oil low on ZDDP?

True. I had bought my supply of Oil around Diwali/Christmas season and got carried away maybe. I am pretty much sure I will be using Mobil Delvac next change onward. However synthetic or not I would still keep to oils that have relatively higher ZDDP levels, and I know Delvac is. I would still not buy just about any oil I can find on the shelf. That is just the way I go about purchasing oil. For example by 2006 F4I gets JASO MA01 Oil and not the JASO MA02 which is much more easily available. My 97 Mitsubishi Pajero gets Delvac. Pretty much for similar reasons.

Originally Posted by zalaps

How on the earth I missed this thread! Drooling! Someday would like to check out in person. Right now can't get over these pictures!
GIFT City & W123 are a contrast that jells surprisingly well!

Thanks for your appreciation!

[Rex RAP]

Need help -- I have a W123 300D, and the glow plug relay has failed. Could anyone suggest where I can get a new one (mine has the original Bosch round pin wiring). Is there any alternate relay that I can use?

[Vmax1200]

Originally Posted by Rex RAP

Need help -- I have a W123 300D, and the glow plug relay has failed. Could anyone suggest where I can get a new one (mine has the original Bosch round pin wiring). Is there any alternate relay that I can use?

My friend had the same issue. He repaired the relay by re-soldering the components. It was repaired in Cochin by a guy who works on high end audio.

[BowMan]

Originally Posted by Rex RAP

Need help -- I have a W123 300D, and the glow plug relay has failed. Could anyone suggest where I can get a new one (mine has the original Bosch round pin wiring). Is there any alternate relay that I can use?

Did you check the relay fuse? There are two types, one is a 80 Amp part number 000-545-03-34-M96. And the other is a 50 Amp part number 000-545-25-34-M96. You can get these on eBay but others might chime in if anyone stocks locally. The relay itself is an expensive thing to replace and I would hope it is just the fuse.

Originally Posted by zalaps

How on the earth I missed this thread! Drooling! Someday would like to check out in person. Right now can't get over these pictures!
GIFT City & W123 are a contrast that jells surprisingly well!

Thanks. You are most welcome to visit. We can connect through PM.

[Screwdriva]

On the subject of engine oil, wanted to share that after much experimentation, I've settled of

Liqui Moly's MOS2

15W40 oil.

The motor is notably smoother and quieter at idle and low revs. It's the only engine oil that has yielded a result within 50 miles of driving my OM617 motor.

One very import note. I completed the Auto-RX engine oil treatment before switching to this oil. A quick search on this will show that ARX is an excellent, slow cleansing agent that helps liquify sludge, varnish and carbon without the use of harsh solvents. In doing so, it helps reduce engine blow by and increase compression without damaging internals. I also did a Liqui Moly Diesel Purge (2 bottles).

Once the fuel and oil systems were clean, I let the MOS2 oil do its work lubricating. The result is measurable.

[Vikram74]

Originally Posted by Chevy_Noir

Hi Fellow Gear-heads,
I'm in the process of restoring my W123 in Mumbai. Any help in steering me towards a good body and paint shop in the city will be really appreciated, especially a shop that has experience with these grand dames. Sadly over the years, the car has accumulated a fair deal of rust in all the usual places.

Hey Chevy , So we’re you able to finally restore your w123 and if yes could you share which mechanic did it for you.

[Jeroen]

Originally Posted by Screwdriva

On the subject of engine oil, wanted to share that after much experimentation, I've settled of

Thanks, that is a very informative Youtube channel. I have watched quite a few of his video’s.

The main reason for the scratching of the cam shaft lobes can be due to the oil. The reason is that when these cars were new, lubrication oils had zinc and phosphorus in them. With the introduction of catalytic convertors, they had to get rid of these, as it effected the cat’s effective life span.

These two components were very important for the lubrication of high pressure components such as camshaft, and to some extend chains as well. (not so much piston and or piston rings I would think)

So zinc and phosphorus was gradually removed from all engine oils. It has been replaced by different additives, you will see it referred to as ZDDP. I believe it was removed from just about all car engine oil, as per international standards from the early 90s or there about. Also, components such as cam shaft lobes were manufactured differently, so they would wear less.

So the older your car is (say pre-80s) the more likely it is your engine could benefit from an oil that makes up specifically for this zinc deficit. At the same time, it also depends on your mileage of course. My W123 runs only 1500-2000 km a year. No matter what oil I put in, wear is going to be very minimum.

I am using Kroon semi 10W40. Which is modern oil, but specifically useful on these older engines.

Jeroen

[Screwdriva]

Originally Posted by Jeroen

Thanks, that is a very informative Youtube channel. I
Jeroen

My pleasure! In my experience, everything that Kent recommends has proven to be tangibly beneficial for my diesel Mercedes vehicles. My standard routine has been to:

1) Perform an AUTO RX engine oil treatment (2 bottles). A quick google search will highlight that there is no safer way to remove sludge, carbon deposits or varnish from your engine interiors, allowing for reconditioning of seals. (It takes 5K miles for a treatment to be completed so make sure you follow instructions precisely.)

During this time, I treat the fuel system by:

2) I perform a Liqui Moly Diesel Purge (2 bottles). If gasoline, then I use Seafoam.

3) I use Chevon Techron fuel additive (diesel or petrol). I use two consecutive bottles at first followed by one before every oil change.

Then, I switch to Liqui Moly's 15W40 MOS2 Engine oil. If the motor needs thicker oil, I use Valvoline VR1 20W50, a extremely refined mineral oil with ZDDP.

The above regimen has seen engine compression and smoothness shoot up, elimination of oil blow by and fuel economy return to "new" car levels.

[Screwdriva]

Originally Posted by Jeroen

It has been replaced by different additives, you will see it referred to as ZDDP.

I've been a large advocate of Liqui Moly's MOS2 oil but only had my own measurements/ observations on its benefits. So this made for interesting reading

https://www.sciencedirect.com/scienc...4316481730830X