Engine Flush For W124, M104 Engine.

[WDB124066]

I have been told by a MB Dealership that Mercedes-Benz DO NOT recommend an Engine Flush of the cooling system for the M104 in a 124.

Has anybody else heard this, or confirm this advice..........?

 

[scillyisles]

Mbworld flushed mine so I will be interested if this is against MB recommendations.

 

[WDB124066]

Thanks for that. The reason given to me was that apparently there is an anti corrosion lining applied to the block. A flush will remove the lining so MB don't even provide a flush for the cooling system.
Now, this sounds a little far fetched to me, so I thought I'd put it out there to see if other people have heard the same from MB........??

 

[kth286]

Do not know if there is an actual flushing liquid, but the merc workshop manual certainly shows a flush with normal water to get all the used coolant (which is very acidic after the 2/3 years use) out from the system.

 

[BillyW124]

I was also recomended not to use flush by my merc indy. He just used water to cycle it through untill water colour was transparent. Then the new mixture was added.

He told me that it may cause more harm than good on an older engine such as mines. Perhaps this may be the general consensus to flushing a 124!

 

[scillyisles]

When I say flush - MBWorld did not use any other flushing agent other than water and flushed the cooling system until the water ran clear.

 

[Will]

Well, Mercedes-Benz actually supply a flushing agent specifically for descaling the cooling systems of their own engines. They list a specific part number and will sell it to you in an MB-labelled tub, but it is just citric acid powder

My own advice is not to use hard water in your cooling system.

Will

 

[WDB124066]

Well, Mercedes-Benz actually supply a flushing agent specifically for descaling the cooling systems of their own engines. They list a specific part number and will sell it to you in an MB-labelled tub, but it is just citric acid powder

My own advice is not to use hard water in your cooling system.

Will

That's what I thought until I asked at the Dealership and was told that MB don't sell a flush for the M104 engine & don't recommend doing it.

I've got distilled water in the system now.

Another question re the additive, MB supplied green additive whereas I thought the M104 should have had brown additive, is this correct??

 

[scillyisles]

Think my additive is blue - yes just checked in garage. It is a turquoise blue colour - part number on bottle is A000 989 08 25 10.

 

[grober]

Thanks for that. The reason given to me was that apparently there is an anti corrosion lining applied to the block. A flush will remove the lining so MB don't even provide a flush for the cooling system.
Now, this sounds a little far fetched to me, so I thought I'd put it out there to see if other people have heard the same from MB........??

I don't think there is such a thing as a anticorrosion lining per se. Its possible the antifreeze anti-corrosion additives have reacted with the water passages and formed a thin protective film on the internal surfaces affording them a degree of protection. Vigorous flushing with water might wash that off I suppose meaning the new coolant inhibitors would be depleted slightly in forming a new protective layer? My guess is if the coolant has been changed at the regular recommended service intervals flushing would be unnecessary. However if coolant changes have been neglected corrosion particulate matter may have built up in the passages and a flush might help remove that.

 

[design guru]

I have a W126 300se and when I flushed my system I used citric acid mixed with water and left it for a few days and then flushed the system with clean water.

It cleared so much dirt from the system I decided to do it again, but this time I thought I would leave it longer. To cut a long story short I left it in there for 7 months using it everyday and using the heating every time I drove. When I did flush the acid and added new anti freeze it still works, no leaks and the heating is perfect. IT has now been 9 months and the heating still works perfectly and there are no signs of leaks and I have not had to top up the system.

 

[Steven Stoole]

The other thing we do here in SA is use washing powder in the system to clean it out. I did this to clean the bottle and system and it seemed to work well while giving the water a nice smell. But I am going to try the citric acid my self as what it does is attack the rust and dirt throughout the system. The only thing you will need to do is make sure you use a bit of bicarbonate to neutralize the acid when flushing it out then place the antifreeze in. Hope this helps.

 

[Dieselman]

Rather than Citric acid, what about using Acetic acid?

 

[tonywashere]

Acetic acid
best on chips, with salt

 

[grober]

Citric acid is an excellent chelating agent, binding metals---- iron in particular . It is used to remove scale from boilers and evaporators. By chelating the metals in hard water, it lets detergents produce foam and work better without need for water softening. In industry, it is used to dissolve rust from steel. On that basis it might not be so effective on the new all aluminium block engines but OK on the grey- iron blocked engines.

 

[millo777]

I would imagine that by now most M104 engines have their head gaskets replaced, and therefore almost certainly had their cooling systems flushed.

as per Steven Stoole, most mechanics will use automatic washing powder to remove any oil from the cooling system. If the problem is rust or limescale, citic flush is probably the best option.

There are plenty of coolant flush products on the market, but I haven't used any so can't comment on their effectiveness, but I doubt any will harm an M104 if used properly.

 

[grober]

I would imagine that by now most M104 engines have their head gaskets replaced, and therefore almost certainly had their cooling systems flushed.

as per Steven Stoole, most mechanics will use was automatic washing powder to remove any oil from the cooling system. If the problem is rust or limescale, citic flush is probably the best option.

There are plenty of coolant flush products on the market, but I haven't used any so can't comment on their effectiveness, but I doubt any will harm an M104 if used properly.

As an enquiry of interest is that automatic dishwashing powder or automatic clothes washing powder? My guess and its only a guess is that dishwasher powder would be better than clothes washing powder but might be useful to confirm that?