White residue - looks like it's coolant related - Page 3 - PeachParts Mercedes-Benz Forum

funola · #31 09-22-2019, 08:59 PM

Quote:

Originally Posted by Screwdriva

It's a 76 240D W115. Pressure test was planned pre-leak but its clear now that the radiator has to come out. The donuts are part of the kits I've linked above.

I'm getting conflicting information on the flush - it's been suggested to citric flush the radiator with the heater on full. Now I'm hearing its best to bypass the heater core?

Your radiator and heater core is 43 years old! They don't last forever and deteriorate faster if the coolant maintenance was not kept up, which looks to be the case by your pics.

If you are going to citric acid flush the heater core, there is a possibility you will get a leak afterwards because the acid will etch away sediments and corrosion that could cause a new leak.

I would not trust these stop leak products. They may work on very small leaks but not on bigger ones.

Screwdriva · #32 10-03-2019, 09:05 PM

Outside of the upper and lower coolant hoses, do you recommend replacing any others hoses specifically? Names or part numbers will do. The water pump is surprisingly inexpensive, so I may replace it preemptively as well.

Appreciate all the guidance here.

Diesel911 · #33 10-03-2019, 10:58 PM

Quote:

Originally Posted by Screwdriva

Outside of the upper and lower coolant hoses, do you recommend replacing any others hoses specifically? Names or part numbers will do. The water pump is surprisingly inexpensive, so I may replace it preemptively as well.

Appreciate all the guidance here.

The Bolts that hold the Water Pump on are exposed to the coolant on the other end and they apparently rust in place. It is not unusual to have one of more bolt heads snap off and there is not a lot of room to drill them out without removing the radiator and so on.

When one guy on another forum had some of the bolts break of I recommended removing the other aluminum housing that the water pump mounts on so that he could drill out the broken off water pump bolts. It turned out in this case to be bad advice because he also broke some bolts off removing the housing.

I will leave it to you to read up on if there is ways of reducing the chance of the bolt heads breaking off.

Screwdriva · #34 10-05-2019, 07:17 AM

Yes, prepared to deal with that with the radiator out. I've purchased Kent Bergma's stainless steel bolts to replace them with, which should solve this issue permanently.

Here's the video I used to learn about this:

https://www.youtube.com/watch?time_continue=416&v=AEHD_OT9gAU

Also, found another hose that I may have missed. Worth changing?

https://www.pelicanparts.com/More_Info/1158311094M22.htm?pn=115-831-10-94-M22&bt=Y&fs=0&SVSVSI=3196

Screwdriva · #35 10-21-2019, 12:24 PM

Citric acid flush complete, using dieselgiant's instructions. Even left the solution in the system overnight for a thorough clean. The result was positive (so far!). Smelly, lightly discolored solution was drained out. Nothing quite as drastic as described in earlier posts. Definitely not dark orange colored.

We haven't pressurized the system yet (waiting on the re-cored radiator) but my mechanic and I don't believe this cooling system to be corroded or in poor condition. Once the radiator is restored, we will install the new dealer sourced thermostat and housing gasket, water pump, hoses (X4) and new oil cooler.

Blue color coolant mix will be the last to go back in. My old-timer mechanic swears by its anti-corrosive properties. Hopefully, this will be the last time we need to touch the cooling system for years to come!

Screwdriva · #36 10-22-2019, 06:33 PM

Was able to get some pictures today.

Pictures 1 & 2 show the thermostat pulled from the housing. We found this black severely degraded and disintegrated rubber hose stuck inside the housing (pictured as it was found). It's clearly perished but we have no idea where it came from or how the system managed to cool with so much coolant flow restricted. Any thoughts?

Picture 3 shows you how clean the inside of the water pump housing is. (We haven't touched it)

Picture 4 and 5 show the factory installed water pump. I find it amazing that a piece of machinery can last 43 years and still run without any leaks. Simply amazing! How did Mercedes loose its way?

vox_incognita · #37 10-23-2019, 09:43 AM

-the thermostat is broken (look for Behr or Wahler with the same setting). "Boil" before install.
-somebody had put the rubber cutouts under the thermostat to (try to) block the smaller circuit(I think one can see the imprints).This might have resulted in the breakage. Or this "modification" was done as a remedy for the already broken thermostat.
-#3 is actually the water pump housing.The vent metal line tends to block. Was available from Febi with the hollow bolts ,reasonably priced.
-Scredriva,while you're there can you check the water pump housing for a logo or brand name? It would be interesting to know who the OEM was.

The proper coolant is G05 (available by Comma- https://www.commaoil.com/passenger-vehicles/products/view/354 ) ,yellow.
Or G48 (blue) . Both are HOAT, G05 lacking 2-EHA salts. Both MB 325.0 certified.

Screwdriva · #38 10-23-2019, 10:07 AM

Will do Vox.

Thermostat and seals on their way from Stuttgart. Do I still need to "boil" the thermostat, whatever that means?

Can't imagine why they would try to block the smaller circuit. I can check the vent metal line to see if its blocked. Or should I just replace it preemptively?

Cheers!

Quote:

Originally Posted by vox_incognita

-the thermostat is broken (look for Behr or Wahler with the same setting). "Boil" before install.
-somebody had put the rubber cutouts under the thermostat to (try to) block the smaller circuit(I think one can see the imprints).This might have resulted in the breakage. Or this "modification" was done as a remedy for the already broken thermostat.
-#3 is actually the water pump housing.The vent metal line tends to block. Was available from Febi with the hollow bolts ,reasonably priced.
-Scredriva,while you're there can you check the water pump housing for a logo or brand name? It would be interesting to know who the OEM was.

vox_incognita · #39 10-23-2019, 04:40 PM

It's advisable to boil the t-stat in water to verify its proper operation (a dvom with thermocouple will do).Try to keep the t-stat raised so it is not in contact with the pot bottom(use a hook or wire)..might be an overkill though.

Kinda difficult to check the metal line while still in place. Hope the hollow screws don't break. The part number - just google 1152000058 co.uk . MB wanted an arm and a leg for the stupid line alone. And yeah,check the new line too for blockage :-)

Who knows what made the guy put the rubber in the housing...people get extraordinarily creative at times

.Or very cheap...

vwnate1 · #40 10-24-2019, 12:12 AM

Well ;

It's certainly clean now ! .

I'm still getting reddish crud in my coolant, maybe I should use a stronger citric acid solution .

You're on the road to wellness, remember : this needs doing periodically, not just by miles .

Screwdriva · #41 10-24-2019, 12:43 PM

My 60 year old mechanic swears that the lack of any orange/ reddish crud in my cooling system is because the previous owner kept a strong mix of G48 (Blue) coolant (glysantin) in the cooling system.

In his words "In the ol' days, 'em cars only had one colour other than tap water..Blue...and it worked really well"

vwnate1 · #42 10-24-2019, 03:17 PM

...That's interesting .

I'm past 60 Y.O. and have never seen blue coolant .

Maybe it's an up market thing .

Green and yellow yes, blue, never .

Alex E · #43 10-24-2019, 03:48 PM

Coolant Color

In 1987 I got a '50 Chevy that was my wife's grandfather's. He died in 1953 and the car sat untouched in the garage for 34 years. I figured the block would be cracked from freezing (alcohol antifreeze). Pulled the dipstick and oil level was full & clean.

That's when I noticed a paper tag on the radiator "Prestone Permanent Antifreeze" installed 1953. It was blue and still good!
Prestone was originally blue!

To keep this Mercedes related I'll mention in the '70's when I was 16 my parents would not loan me $300 to buy a cherry '53 W187 coupe, "too old" they said. I still think about that car...

Screwdriva · #44 10-25-2019, 01:46 AM

Quote:

Originally Posted by Alex E

Coolant Color

In 1987 I got a '50 Chevy that was my wife's grandfather's. He died in 1953 and the car sat untouched in the garage for 34 years. I

Interesting you say that. My W115 sat in a garage for 10 years with the glysantin coolant. Not a spec of rust!

vwnate1 · #45 10-25-2019, 09:33 AM

You guys are lucky ~ I'm still finding opaque stuff in my distilled water.....

It's lighter colored now though, orange instead or red so maybe I'm getting there .

Good thing I found .80 cent gallons of distilled water at wallymart .

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