S-Prihadi

This is what happen when MB Indonesia uses both high TDS water and probably under 35% antifreeze/coolant concentration.
Bought this car used at 9,700KM there about 3 years 4 months old in May 2017. That means it just expired its warranty for 4 months when I got it.
3 years is MB warranty in Indonesia. So that means there was never a need for coolant change during those years.
I believed the coolant is still original from local MB assembly line when I took this photo as database in May 2017.


It originally has the clear yellow coolant. I do not know its part number. The one I replaced it with in 2017 Aug is the blue one Coolant mercedes MB 325.0 ( P/N A 000 989 08 25 ) at 10,773KM.




On 17th June 2019 , approx at 17,000KM ish, or 6,000KM ish later after coolant change.......bad luck and a blessing in disguise happened.
My driver just arrived home and then in 30 minutes parking .... Whooshhhh....... the coolant hose at lower engine block side simply came off
The one I circled red. Coolant all over the garage. Good thing not at highway speed when this occured, or else bye-bye warp engine block.


So as you can see above, when original/old coolant was flushed, the radiator hose in photo circled red was removed to speed up draining and the clip L-bend orientation was installed wrong...LOL.

The working space is very unfriendly because I got the aftercooler blocking and its is so low down, its difficult to reach from the top.
It is easy to work from the bottom with car jacked-up, but one work by feel only, can't see proper hose entry and its "click" of the clip.
This is best done with 2 person one from top one from bottom.



Its location is as below :



If working person on top wants to see what he is touching with the hose, he has to have small and long hands ...LOL.




Now come the blessing in disguise part. Only then I managed to see, how corroded the steel hose end is.





So I filled up the cooling system with distilled water first while waiting for new concentrate coolant on order, and I also ordered the new Clips.
I let the car run with distilled water for a few days before I add 50/50 new coolant and distilled water.
All good. No leak.

But for anyone doing this hose install, do watch out for something : This steel hose end insertion depth at the lower side engine block is different than the rest using the same steel hose end.
It is deeper insertion, as such you would not see the hose end steel "rim".



The retainer clip is kinda cool clip and it does not like being removed completely as it will loose its pre-tension. Attached MB WIS. I labeled as Hose End Retainer Clip.pdf
Pull up clip a mere 7mm or so, and pull hose out.
To insert hose, let retainer clip in locked position and the small "hill" on the steel hose end will push the clip up and clip will get locked into hose end groove.
Do I like this kind of retainer clip for vital duty like 1.xx BAR coolant pressure ? NOPE.



Since 50/50 measurement of coolant to distilled water is not easy to be VERY accurate using common 1 liter beaker.
I use 2 gram accuracy weighing scale.
The concentrate coolant specific gravity is 1.09. So 100 grams of distilled water and 109 grams of concentrate coolant is 50/50 accurate.


So the story still continues............
On late Oct 2019, I did my 20,000KM oil change.

The day before workshop visit, my driver reported coolant lost for the first time of 1.5 cm on the reservoir and he can see minor droplets on the underside tray.
So let's get the mechanic to see where the leak comes from at the workshop.
Since I am changing my serpentine belt too, due to its age of 6 years ( car engine left germany in Aug 2013 ), albeit low mileage..the aftercooler has to be removed too anyway.

So I will have access to the plastic hose end receiver at lower side engine block.




Will continue in next post..................

S-Prihadi

PART 2

When arriving at the workshop, no leak occured and all wet traces of leak gone.
So oil change only .

Fast forward, next workshop visit a week later when parts arrived........... bought below hose + its black o-rings at hose end and the orange seal of plastic hose end receiver at engine block

Mechanic suspected the item 170 o-ring/seal



Me suspected the rusty hose end has pushed out the o-ring from its seating position. I seen such leak before on other engines.




This is typical of "hard water", scale build up.



At this stage I am very pissed with MB Indonesia quality control on its water for coolant mix.
At the same time I am also wondering what poor anti rust coating MB uses for its steel hose end ?


Fast forward ........new tee hose assy item no 150 and both end o-rings and that orange seal installed.
Also new brake pads front and back.




I tried to inspect hose no 60 hose's end at the no 80 black 0-ring.... which is the hose for the thermostat housing, but it won't come off. Damn, its steel hose end must have swollen the black o-ring too.
Since I have not at this point in time bought a new no 60 hose, I dare not play rough with it as I fear the hose itself will slip out of the steel hose end crimping.

Fast forward.........
So I ordered two new hoses, hose no 60 and no 200, where they have steel hose end fittings. I want to "reset" all the hoses with steel ends. Start fresh.
I have not yet installed these two hoses, maybe next week.




So I examined closely hose no 60 hose ends. Need close up photo to zoom, me eyes close up not good.
Indeed it has super minor leak, or else such mineral deposit from hard water will not be there. Radiator side.







Same super minor leak here, at thermostat housing




The smallest hose no 200 steel hose end me have not inspect yet, I will change it anyway.



So next work aside from changing the new 2 hoses, I will also change these seal and o-ring. This then becomes a complete total reset.



What could be only a US$3 for distilled water MB Indonesia could have use for coolant mix, and proper 50/50 coolant ratio at say US$50, now it cost me A LOT of $$ to reset/remedy.
But the good side of the story is, at the least I know MB hose end rust protection coating is crap

Will update when I get to change the other 2 hoses and 2 seal/o-ring and see what mineral deposit I can find building up there at the thermostat housing.


BTW, what is the yellow coolant MB uses, I mean is it HOAT or OAT ?
When did MB start using blue one ?
Thank u in advance


The blue one A 000 989 08 25 ( 325.0 ) I know what it is : It is basically the old fashion Silicate and a bit of Borat. I like this old fashion one, the silicate.


End for now......

S-Prihadi

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The final repair............. PART 3

I was so busy end of year 2019 and up to Feb 2020, I have not proceed with changing the 2 hoses where they have steel ends and potentially would be corroded .
I wanted to change them hoses and the 2 seal/o-ring on the thermostat housing to "reset" .

Sometime in late 2019, the cooling system has a leak again, albeit minor leak at approx 50 -100cc per 1,000KM.
I know the leak is not at the radiator, but somewhere on the engine. The leak is so small, it never reached my garage floor, it got dried on the underbody cover.
All I can see is the greenish residue from dried coolant on the undercover body and a bit under the water pump.
Was it also partly a weak radiator coolant reservoir cap too ? I don't know.

So early March 2020 I sent the car to my friend's workshop to change those 2 hoses and 2 seal/ring and remove + inspect the water pump.
I was in bad luck, the radiator pressure tester at the workshop, their hand pump recently was out of action.
So I can't do pressure test prior to changing the hoses and seal/o-ring. I am curious to see the pressure loss vs time and where actual coolant leak out under pressure, and if the 2 coolant reservoir caps is micro leaking.
I have checked the engine oil level and condition when the cooling system started loosing 50-100cc per 1,000KM late 2019, just in case a minor leak at the cylinder head gasket and coolant into oil occurs....... all good. Wheewww.

I was so pissed, how can a car properly maintained by 1st owner and myself as 2nd owner, and under 6 years old and only <22,000KM .......has a leaking cooling system ??

I have replaced the coolant 1st time on Aug 2018 at 10,773KM. I don't use coolant for more than 2 years, regardless of what MB claimed or reccomended.

I replaced again the coolant, for the 2nd time on June 2019 at approx 17,000KM because of that 1 hose, its metal hose end popping out of the pump suction port and I loose lots of coolant.
Before I did the 2nd coolant change, this time I ran the car for a good few hundred kilometers with distilled water first .....after 2nd flush, no other flushing chemical used.

When I sent the car for PART 3 repair early March 2020, it was at 21,336 KM.
So, my cooling system has been running new blue coolant for approx 10,000KM.


So the story goes...............
Time to change the 2 hoses and seal/o-ring at the thermostat housing and inspect the water pump.
The aftercooler has to be removed....damn.
The serpetine belt and one of its tensioner has to be removed....damn damn
The MAF / Throttle body has to be removed in order to remove the thermostat housing to replace its two seal/o-ring... triple damn.

Hose #60



This hose #200 only has one metal hose end.




No choice but to remove and inspect the water pump this time.








NOTE : The grease-looking brown slime is not grease. It is slime.


So, it was clear that the new coolant for approx 10,000KM of use, has cleaned the cooling system.
As such the previous bad hard water ( high TDS ) with probably insufficient coolant concentration MB Indonesia used ,which resulted in a calcium+whatever shiet deposit ....now been sort of "cleaned" and
then leak occurs at the gasket of the water pump. Calcium built-up can close up minor leak/s.

As to why all the hoses with steel ends can corrode while supposedly MB Indonesia uses the clear-yellowish coolant in 2014, I can only speculate that the concentration
of the coolant was way too low and hence the typical 3-4% corossion inhibitors in a coolant became too diluted/insufficient.
BTW : Glycol/coolant on its own without corossion inhibitors IS corossive when degraded.
https://www.process-cooling.com/arti...thylene-glycol
http://www.worldpac.com/tagged/MBZ_ANTIFREEZE_G48.pdf
All coolants main component is ETHYLENE GLYCOL

So I got double whacked by MB Indonesia. Poor quality water and very most likely insufficient coolant concentration.

Inspected the water pump shaft bearing, all good.
So I do not need to buy complete water pump assy, only gasket,....Nice !!
Clean all traces of calcium deposit and dirt/slime from the water pump and engine.

So everything was re-installed with the 2 new hoses and 2 seal/o-ring and new water pump's gasket.
Filled new coolant 50/50 with distilled water. Damn this is my 3rd time I replaced the coolant in 10,000 KM in less than 1 year.
Run the engine with heater ON and aircond ON for 30 minutes idling and some 4,000 RPM revs thrown in for 2 minutes.
No more coolant leak ....Yipeee !!

It was late 6PM ish and I decided to leave the E400 at the workshop and collect the car the next day.

The next day I came back to the workshop.
The mechanic told me that in the morning they discovered a very very minor leak from the water pump and they on purpose left the leak droplets untouched
for me to see for myself. It was the main shaft seal of the water pump micro leaking !!! Bloody hell...why no leak yesterday during the 30 minute test ?

Holy crap, those what I assume as calcium built-up is like having 200 grit sand-paper abrasiveness towards the pump mechanical seal.
So, ordered a new pump assy and the previous gasket is still good for re-use as it has not melt its special adhesive line....yet.
The gasket has a built-in adhesive line which I am sure it is heat activated.

Here we go again......... remove EVERYTHING once more to replace the water pump.
Again, I filled up at least new 50% new coolant + distilled water mix, I can't recover all 100%.
So, its like 3.5 times coolant change in 10,000KM

No more leak so far, but I only ran the engine from workshop to my home 6th March in bad traffic and only yesterday 5th April I drove it 20+ miles aggresively on the highway.
My city is on a soft lockdown due to Covid-19 since 14 days ago, so I did not really feel like testing the E400 earlier last week.
Yesterday 20+ miles was a badly needed run for the E400 to prevent rust on the brake system , tire stationary damage and engine oil being too dry on the engine upper region like camshaft and the timing chain.

I hope there will be no PART 4 of this post.... LOL.

End of Report.


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