motor or tranny mounts. dont ask how i know.

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I agree. motor mounts can look fine, but be bad.

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

I replaced the motor mounts 26,000 mi. ago (1/2005).

Transmission mount(s) never replaced.

176,000 mi. on the odometer (reliable number).

Again, the vibration/noise is only between 1,400 and 1,600 RPMs (idling or driving, makes no difference which is the case).

Incidentally, this problem presented shortly after I replaced the original bowden cable
(click here
http://www.peachparts.com/shopforum/showthread.php?t=291245
for the horrid [but successful] job story).

Take a #2 pencil try to fit it between the engine mount cup and the aluminum mount bracket.

If it passes through freely they are OK.

If it does not fit or you feel resistance/contact = the engine mount is junk (regardless of miles).




.

__________________
ASE Master Mechanic
asemastermechanic@juno.com

Prototype R&D/testing:
Thermal & Aerodynamic System Engineering (TASE) Senior vehicle instrumentation technician.
Noise Vibration and Harshness (NVH).
Dynamometer.
Heat exchanger durability.
HV-A/C Climate Control.
Vehicle build.
Fleet Durability
Technical Quality Auditor.
Automotive Technical Writer

1985 300SD
1983 300D
1984 190D
2003 Volvo V70
2002 Honda Civic

https://www.boldegoist.com/

How're your exhaust hangers?

The fact that it happens at a specific rev range makes me think it's something loose or not properly supported that's resonating at that frequency.

The motor mounts and trans mounts can cause problems for each other....
I kept having to replace the driveshaft mount on a chev pickup.... and later found that a cracked ( a clean line you could not see ) engine mount was allowing too much movement and messing up that driveshaft support... same with most tripartite engine trans supports.. all should be replaced at same time if any doubt exists..

Also, there are VERY SPECIFIC instructions in the FSM about positioning the motor mounts correctly.. including a home made tool for checking the position.. if you just installed them last time.. they may have cracked.. or may be transmitting vibrations due to binding and misadjustment.

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1980 240d ,

chain elongation, cam marks reference:
http://www.peachparts.com/shopforum/showthread.php?threadid=10414

http://www.peachparts.com/shopforum/diesel-discussion/305365-9-degrees-chain-stretch.html

evap fin cleaning:

http://www.peachparts.com/shopforum/showthread.php?t=156207&highlight=evaporator

A/C thread

http://www.peachparts.com/shopforum/diesel-discussion/297462-c-recommendations-mb-vehicles.html

Ok. I'll be first looking at the motor mounts as whunter pointed out. Then I'll check the rest of the supports as suggested. Will go back to the FSM (I have the old paper copies) and reacquaint myself with the motor mount install.

If I replace the motor mounts, is brand significant? I see that Lee is offering here a generic, Lemfoerder and Corteco and ranging from $20-$63 each.

Thanks for the observations and help.

Could be as simple as the air filter canister tapping the valve cover at a specific rpm span. Hold the canister with one hand and bring the rpm up with the other. See if the noise goes away.

__________________
1984 300SD turbo 126
"My true love"

God made me an atheist and who am I to question His wisdom

[The car is a Calif. model so it has the unusual air filter canister that goes with the I'll-fated trap oxidizer] As per post# 13

The OP car is a Calif. model 300CD, so the air filter sits behind the R/F head light. no way it could hit the valve cover unless that engine is really rockin and rollin .

Janamarie, I don`t know what a "balance shaft belt" is, the car in question is a W123 model. maybe something the newer models have as per your picture.


Charlie

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there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

See the picture. Head/valve cover are way to top right corner.

Bump: Anyone have any opinions about brands of motor mount if I find that the one(s) installed have already failed?

Attached Thumbnails

 

Call Phil and ask for "PHOENIX" brand.

When not available, I use Lemfoerder or Corteco.

Excellent. Thanks.

Am I wasting my time with the Febi ones I've bought?

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

They are OK.
I use them, just out of stock at the moment.

Thanks - good to know!

__________________
1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!