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Let's have some fun and get knowledge while at it..........
The A1 engine mount is the VERY worn out one. Approx 83,000KM and 13 years old today 2023.
When it was still 71,000KM in 2021 at 11 years old, this is its photo.
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This car mount was already sending mild vibration to steering wheel and chassis overall.
At that time, for idle vibration quality, I being first time touching this car at such age and mileage, assumed that a 4 cylinder M271 ( 1.8L Turbo ) which uses dumb-azz Lanchester counter balance shaft won't be as "smooth"
as my V6 which is 2 more cylinders and no need counter balance shaft.
Even my Toyota 1.8L: 4 cylinder from brand new, can't at idle.... be as smooth as my M276.820 by steering feel sensing and overall vibration of the car.
I did tell him though to replace the engine mounts x 2 and the tranny mount, but he said later.....
Few months back, his W204 has a flat battery, so I assisted him and I used my old & retired 2021 battery to start his car and I took the car home to test parasitic load.
When I started to drive his car and more so when gear engaged, HOLY MOLLY.... the freaking engine vibration towards the steering is so strong !!!
He said he can't feel anything different....LOL. Numb azz-dyno he has
So both engine mounts and tranny mount replaced sometime ago and I told him, give them to me for autopsy.
So, here we are :
The A1 is the worst worn out one, and I assumed it must be the LEFT side one. Too bad the P/N are both the same for L and R side, so I can't ID which side it came from, unlike my car.
Some gang-bang have occurred ....LOL
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I can not really the difference between the W204 and my W212 engine mount visually, only the weight is up to 17 grams heavier for my W212
The stiffness of the mount if tested by hand. A1, A2 and B1 tested.
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Tested using weight.
Sorry, I use the digital angle meter only much later on, so A1 never get the angle read. But you can tell by the drop visually, it is a GONER !!!
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Verification of weight, of the lead used. This is a diving weight belt and lead .....LOL
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This is not oil. It is very watery. I do not know if the liquid color is naturally dark purple black-ish or because of the rubber ?
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The layout.
IN = inward side, to engine mount big stem rubber
Left is O or outside, that is to small rubber cup. Right side is INward side. A, B and C are fluid flow holes or path
I believe the rubber membrane I marked FIXED, those 2 got over-pressurized and hence top images shows the rubber kind pop-out of its parking spot.
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The life and stiffness of the mount is 99% depending on the big rubber stem and not the liquid.
Below is the damage profile of the big rubber stem.
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So the liquid is the comfort maker. Its like damper between the rubber mount to the car.
I don't understand how the liquid A, B and C flow holes/path actually works other than liquid can flow between chamber A to B and vice versa.
I mean, in a car damper/shock absober I know exactly how it works.... but not on this mount.
The mount is probably made by WEISS Germany. https://www.weiss-world.com/de-en/In...ity/automotive
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I personally being very sensitive and know my car so well, will put no more than 30,000KM ( 18,600 miles ) as good comfy life out of the engine mounts + tranny mount. Maybe less for tranny.
This is based on my driving style, engine power and road condition.
Engine mount must be "measured" visually with LOAD.
Here is what the B1 and B2 engine mounts of mine were like before I replaced them.
Left is my B2 when it was removed at 18,000KM or 11,180 miles.
LOADED B1 ( Left side )
B2, right side, loaded.
Now at 39,500 KM or 24,534 miles, where this means the current engine mounts are at 39,500 less 28,700 KM = 10,800 KM ( 6,708 miles ) old
This is Left Side
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This is Right side
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Let see when at 20,000KM or 12,422 miles, or when my azz-dyno already sense the mounts lost its creme de la creme vibration isolation goodness.
I admire your devotion to do the things "just because you can"
Been dealing with "liquid filled MM" for about 25 years and I could never confirm they are really riding on liquid.
For me the liquid you see is just rain water , or oil leaks making it there.
When living in dry climates, all MM I replaces were always dry.
Anyway, I prize the latest MM design, who gives it rubber flange, so when the main mount fails, you still have rubber pad the engine is resting on and not metal-to-metal.
My conclusion about MM is "if in doubt - replace it".
That was easy on previous models, where MM in the past cost me $50.
I replaced them this year on W212 and shopping around, I spend about $500 for 2 of them.
Those things are not cheap anymore.
I admire your devotion to do the things "just because you can" Been dealing with "liquid filled MM" for about 25 years and I could never confirm they are really riding on liquid.
For me the liquid you see is just rain water , or oil leaks making it there.
When living in dry climates, all MM I replaces were always dry.
Anyway, I prize the latest MM design, who gives it rubber flange, so when the main mount fails, you still have rubber pad the engine is resting on and not metal-to-metal.
My conclusion about MM is "if in doubt - replace it".
That was easy on previous models, where MM in the past cost me $50.
I replaced them this year on W212 and shopping around, I spend about $500 for 2 of them.
Those things are not cheap anymore.
Did you tear-down the mounts like I did before they get overly abused ?
I don't know if diesel engine get different mounts or not due to its more vibration by nature and massive torque it has if 3.0 liter.... but my W212 and the W204 is a guaranteed 100% liquid fill.
The liquid sealing method is very good and simple as this is not above the atmospheric pressure system, unless the bottom thin rubber boot shaped membrane get torn, you will find the dark liquid there and it is not rain water.
As I said at the beginning of the post, we all need to learn .
W212 is 1st MB with MM who are closed cup.
Previous model simply had the top with rubber stick into big hole, so when removed them after long time, they would come apart.
The rubber at this point is so mangled, that it is hard to determinate if the rubber could have fluid pocket.
So again, if it did have, I could never recognize it.
12-14-2023, 09:14 AM
