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Metallic sound from 6.9 engine front end?

Started by Jan S, 09 May 2022, 10:22 AM

daantjie

Ticking could also be an exhaust leak right at the manifold.  The "tick" is actually an air pulse/puff.  Usually it is worse with cold engine then as the heat makes the metal expand the sound gets less pronounced.  You can also use a length of hose and probe with one end then hold to other end of the hose to your ear. 
Daniel
1977 450 SEL 6.9 - Astralsilber

Jan S

Quote from: daantjie on 18 September 2022, 02:59 PMTicking could also be an exhaust leak right at the manifold.  The "tick" is actually an air pulse/puff.  Usually it is worse with cold engine then as the heat makes the metal expand the sound gets less pronounced.  You can also use a length of hose and probe with one end then hold to other end of the hose to your ear. 

Interesting, thanks for the tip! Search continues .....
1975-mod W116 450 SE with 6.9 engine

Jan S

Today I took off all the belts.

Ran the engine without alternator, fan/water pump and power steering pump for 1-1.5 min.

The great news is that the engine ran smooth as a warm knife in butter  :)  Fantastic to hear!

The noise must be coming from the fan/water pump or maybe the power steering pump (the alternator moves smoothly).

Stethoscope test gives no further information ... for an untrained ear.

Any thoughts?

Replacing the water pump is a big job, I guess, and difficult to get a new/renovated pump?
The steering pump is easier to get, I assume
1975-mod W116 450 SE with 6.9 engine

rumb

#18
I believe MB sells them for a princely sum of @$1150

I understand rebuild is difficult. Some out there have done it.

old thread, someone in australia was rebuilding them
https://forum.w116.org/mechanicals/6-9-water-pump-replacement-2/msg53322/#msg53322

Here is a thread on removing the pump.
https://www.topklasse.org/forums/threads/6-9-water-pump-replacement.4636/

Here the real info:
https://forum.w116.org/mechanicals/mercedes-6-9-water-pump-overhaul/
'68 250S
'77 6.9 Euro
'91 300SE,
'98 SL500
'14 CLS550,
'16 AMG GTS

Jan S

Thanks, Robert

I'm not seeing the pics ... are you?

I also found this great thread from 2019: https://forum.w116.org/mechanicals/mercedes-6-9-water-pump-overhaul/

My cooling temp is where it should be and stable. I don't think I have a leak in the water pump. However, the noise comes from the water pump and/or the power steering pump. Hard to say.

Search continues ...
1975-mod W116 450 SE with 6.9 engine

Randys01

Ok  rat down which one it is......pwr stg pump is unique to 6.9 but bearing/seal kit etc are off the shelf.
As yours is not a 6.9 you could run a std pwr stg pump for ease of change over.
The water pump is another story...there are two versions...square and round. The respective pump must fit the respective base.
If the classic Centre still has water pumps BUY one!..........oh they're a nightmare!%#

Jan S

Quote from: Randys01 on 25 September 2022, 12:33 AMOk  rat down which one it is......pwr stg pump is unique to 6.9 but bearing/seal kit etc are off the shelf.
As yours is not a 6.9 you could run a std pwr stg pump for ease of change over.
The water pump is another story...there are two versions...square and round. The respective pump must fit the respective base.
If the classic Centre still has water pumps BUY one!..........oh they're a nightmare!%#

Thanks!

Yes, search continues ....

It turns out the steering pump is from a W126 380 SE (part nr. A 126 460 1480 with 82 bar) but seems to fit the 6.9 engine ... as far as I can tell. A previous owner in the US must have installed it.

I assume the steering box is from the original car, i.e. 1975 US 450 SE 4.5 liter.

Square and round water pump ... how can I see the difference? The engine is a 1977 US 6.9 if that helps.
1975-mod W116 450 SE with 6.9 engine

Randys01

The year etc won't help in determining whether it is square or round type.
This post  is not helping as I can neither send/read attach and I dont post BUT someone else will surely chime in with a picture.

Jan S

Anyone has pics of square and round water pumps?

I'm trying to determine which one is in my car.

1975-mod W116 450 SE with 6.9 engine

raueda1

Quote from: Jan S on 27 September 2022, 05:24 AMAnyone has pics of square and round water pumps?

I'm trying to determine which one is in my car.


If you can see it at all it's pretty clear.  There are 2 aluminum pipes going down from the rear of the water pump body on the front of the block.  The pipes are either round or rectangular.  Mine are round though my impression is that rectangular is more common.  Cheers,
-Dave
Now:  1976 6.9 Euro, 2015 GL550
Before that:  1966 230S, 1964 220SE coupe, 1977 Carrera 3.0

Randys01

Funnily enuff I came across a couple of spare pumps in storage after 5years and as Dave has said...the square one has square-ish pipes and the round one is definitely round pipes.