Hi,

On my 1986 190E four-cylinder, I had a failed engine mount on the exhaust side that meant the engine vibrated a lot. This was replaced with (if I remember right) original parts, or at least good quality replicas (have heard bad stories about replica engine mounts..).

Then, the engine developed a rattle. It's heard best inside the car with the windows closed. It's the sort of rattle that sounds like a timing chain rattling, or as if someone left a screwdriver under the bonnet..

I replaced other engine mount, no improvement.

It's worst in 'D' at idle, still there driving at low speeds, not so bad in 'P', and gone in Reverse.

What's causing it?

Russell

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190E's:
2.5-16v 1990 90,000m Astral Silver
2.0E 8v 1986 107,000m Black 2nd owner
http://www.maylane.demon.co.uk/190esmall.jpghttp://www.maylane.demon.co.uk/190esmall2.jpg

Not an expert by any means (since I attempted to replace motor mounts on my W124 a couple of weeks ago...still can't get the bolt off the driver's side mount ), but it sounds like the new motor mounts cured the engine vibration, but exacerbated the transmission mount(s) if there are any. The clue to me is the different symptoms you are getting depending on gear selection...

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2009 ML350 (106K) - Family vehicle
2001 CLK430 Cabriolet (80K) - Wife's car
2005 BMW 645CI (138K) - My daily driver
2016 Mustang (32K) - Daughter's car

I would also check your exhaust to trans mounting bushings if your car has these (my W124 does). After you replace the motor mounts, thereby damping the engine vibrations, all sorts of other noises become more apparent. The noise you describe could be these bushings, or, as G-Benz states, it could be the tranny mount.

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08 W251 R350
97 W210 E320
91 W124 300E
86 W126 560SEL
85 W126 380SE Silver
85 W126 380SE Cranberry
79 W123 250
78 W123 280E
75 W114 280

Not sure I understand - if it's worst in 'D' and idle, those are conditions you can duplicate (with caution!) with the hood up and you looking around for the source. If you need to slide underneath, set it up completely on jackstands so the drive wheels are off the ground.

Might be a shield on exhaust of cat converter, if you have one.

Steve

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'91 MB 190E 2.3
'08 RAV4 Ltd 3.5
'83 Lazy Daze m'home 5.7

yes, check the exhaust for clearance. if you had work done on it it may have taken a "set" with the bad mounts that is now causing a clearance problem.

you may need to remove some clamps and twist the pipes to eleminate it.

tom w

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

You are sure that the fan blades are not striking the fan shroud?

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2012 E350
2006 Callaway SC560

Did you check the exhaust to trans mount bushings?

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08 W251 R350
97 W210 E320
91 W124 300E
86 W126 560SEL
85 W126 380SE Silver
85 W126 380SE Cranberry
79 W123 250
78 W123 280E
75 W114 280

If it rattles with the motor running, push the motor to one side and then the other and see if the rattle goes away. Does it rattle on a hard right turn or a hard left? If so, you probably have bad mounts. If they are original Mercedes mounts and it is less than 12 months (unlimited mileage) from the date on your receipt, Mercedes will replace them including labor under their parts warranty. (The warranty information is printed on the back of your parts invoice.)

At 135k I replaced the original mounts on my 92 300d (they are the hydraulic ones) with aftermarket mounts. The motor rattled just like in your description and I figured that the noise was something else since I had new mounts. I changed the transmission mount and checked the exhaust mount and it still rattled. Then I contemplated changing the lifters, the idler pulley and all sorts of things until a mechanic leaned in the motor while it was running and caused the rattle to go away.
Year or so after that (at around 165k) the mounts collapsed so I bought original parts from Caliber. When I installed them all of the noises disappeared.

In your case, the original mounts cost the same as aftermarket mounts, are higher quality and have a better warranty.

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Tom Hughes
St. Louis
84 300SD
92 300D
86 300SDL

Very common rattle on these is from the top bushing on the tensioner damper.
They usually show up at idle , in gear. Have someone do just that as you stick a screwdriver in at the bushing to tighten up the slack. You will see it right away and it can be cured by sandwiching an O ring around the mounting bolt to take up the side to side slack.

Archieves.

http://catalog.eautopartscatalog.com/mercedesshop/sophio/wizard.jsp?partner=mercedesshop&clientid=catalog.mercedesshop&baseurl=http://catalog.peachparts.com/&cookieid=1M30LAGSC1TR0Z7Y9Z&year=1986&make=MB&model=190-E-002&category=G&part=Acc.+Belt+Tension+Damper&appEngines=_any

my post regarding checking exhaust for adjustment issues applies to the fan shroud too. it can be moved around a bit if it is hitting after the new mounts.

tom w

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.