Hi folks,

This one has me baffled, story so far - new aux belt(Conti), tensioner and arm, water pump and alternator (not new but removed from working vehicle without issues).

The problem, the belt squeaks when making right hand turns, fine on left hand, also when damp outside - noise is less, also a liberal squirt of WD40 gets rid of it for 100 or so miles.

..any ideas?


Cheers,

__________________
David


1996 Mercedes S124 E300TD - 129k - rolling restoration project -

1998 Mercedes W210 300TD - 118k (assimilated into above vehicle)

Sagging motor mounts?
when you turn, the engine also rotates (think “roll” in an aircraft). Upon making a turn you are causing something to shift and make noise. The WD40 is lubricating the contact point until it eventually wears away.

__________________
The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech

Check engine mounts.

Sixto
98 E320s sedan and wagon

New engine mounts, last year - went out and swapped it around, letters facing front, are the belts directional by any chance?

Under closer inspection one of the V lines looks closer to the edge than otherside, it also looked very slightly chaffed.

I thought it may have been the extra load on PS pump when turning causing belt to slip, doesn't do it when stationary though.

__________________
David


1996 Mercedes S124 E300TD - 129k - rolling restoration project -

1998 Mercedes W210 300TD - 118k (assimilated into above vehicle)

Double check your serpentine belt routing, it is _just_ possible to install it wrong and then it will be a little too loose and perform as you describe.

__________________
Respectfully,
/s/
M. Dillon
'87 124.193 (300TD) "White Whale", ~392k miles, 3.5l IP fitted
'95 124.131 (E300) "Sapphire", 380k miles
'73 Balboa 20 "Sanctification"
Charleston SC

..ta max, couldn't find a pic, but mine has the tensonior smooth cog sitting on the outside of belt, it then doubles back sitting on the outside of all V pulleys'


edit, cant seem to post images from Google anymore, encryption city

Tkae two:

__________________
David


1996 Mercedes S124 E300TD - 129k - rolling restoration project -

1998 Mercedes W210 300TD - 118k (assimilated into above vehicle)

Messed around with a few option, checked belt config - all okay there, the noise seems constant (but not very loud) on each lock, wondering if the P/S fluid being old could be causing the squeal?

I agree with the comments relating to lock causing engine to rise/fall, thing is all the whirrly bits move too -

__________________
David


1996 Mercedes S124 E300TD - 129k - rolling restoration project -

1998 Mercedes W210 300TD - 118k (assimilated into above vehicle)

Guess what this turned out to be...would you Adam & Eve it..


Changed part of the PS fluid using oil suction gizmo, waiting for new filter to arrive to complete flush/change..

I don't know why but over looked this when flushing SLS, not to worry, hopefully help someone else experiencing similar problem.

Used Dex 3 as opposed to actaul PS fluid, just had it to hand.

Good video

https://www.youtube.com/watch?v=S2CRnUcpOjs

__________________
David


1996 Mercedes S124 E300TD - 129k - rolling restoration project -

1998 Mercedes W210 300TD - 118k (assimilated into above vehicle)

Filter arrived, this one is supplied without the gasket which I think refers to the lid - good vales at around $6 delivered.

Highly recommend oil suction gizmo, thin tube can fit inside the feed/return to a degree.

__________________
David


1996 Mercedes S124 E300TD - 129k - rolling restoration project -

1998 Mercedes W210 300TD - 118k (assimilated into above vehicle)

I know what everyone is thinking, simple fix ..but this remains unresolved and my last project ..

On right turns low/high -ish speed it squeaks like crazy, no problem left turns silent.

Attempted remedy so far, three new belts of different brand, currently using Continental.

Flushed power steering fluid, replaced doughnut filter.

New tensioner arm and piston damper.

No a/c fitted

__________________
David


1996 Mercedes S124 E300TD - 129k - rolling restoration project -

1998 Mercedes W210 300TD - 118k (assimilated into above vehicle)

Does it happen when you turn the steering wheel when the car’s not moving? Maybe you have a bad steering box.

Sixto
98 E320s sedan and wagon
02 C320 wagon

I'd suspect a steering box problem too. The PS pump is going to do it's thing regardless of what position the wheel is in. The same force should be required to turn left as to turn right. The fact it only screeches the belt in one direction indicates that something is binding up or having problems.

__________________
Current stable:
1995 E320 157K (Nancy)
1983 500SL 125K (SLoL)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Gone and wanting to forget:
1985 524TD 167K (TotalDumpster™) [Definitely NOT a Benz]

..this sounds daft, but the engine tray is off and weather wet - is the belt getting splashed causing it to slip, it is intermittent

Sunny day, will take a car park and investigate above points too..

__________________
David


1996 Mercedes S124 E300TD - 129k - rolling restoration project -

1998 Mercedes W210 300TD - 118k (assimilated into above vehicle)

Renew the belt tension spring. They do get old and tired.

Double check the belt for correct length.

__________________
Respectfully,
/s/
M. Dillon
'87 124.193 (300TD) "White Whale", ~392k miles, 3.5l IP fitted
'95 124.131 (E300) "Sapphire", 380k miles
'73 Balboa 20 "Sanctification"
Charleston SC

Will do, just back from test drive..

It's louder but that could be part of drying out.

I am wondering if the belt got contaminated with oil from leaky crank seal, everything else (especially the underside of tensioner arm) had a oily coat.

Sixto, only does it while moving, had four wheel alignment a while back too.

__________________
David


1996 Mercedes S124 E300TD - 129k - rolling restoration project -

1998 Mercedes W210 300TD - 118k (assimilated into above vehicle)