W220 3.2 CDi - Reverse Mirror/Rumble at 70mph/Rough idle

[Suhayl Tariq]

Hi,

New here,

been a serial lurker for a while and thought i would jump in and register as my enthusiasm level is 10/10 and mechanical skills are -10/10!

i have my S W220 3.2 CDi, owned her for nearly 7 years. Shes done 120k miles

Daily driver with the usual faults of air suspension, air con, heat sensors etc etc. all been repaired/replaced with genuine parts by the local indie. Its been serviced as the schedule, original filters, oil etc are used.

The car will probably end up back with him, but I wanted to learn a bit more about the car and how its put together before i take the car to the garage for him to look at and advise.

Been on various youtube channels, spoke to a colleague of mine and a car dealer i know so if anyone here could shed some light, i would be very grateful.

Thank you!

Sorry for the long post!

Q1 - Passenger Side Mirror
When you select revers, the mirror used to dip towards the kurb to allow you to park better. Great feature and helped to keep the alloys scuff free. This was working really well until a few months ago. Now when you select reverse, the mirror slides up, down, left right and ends up focusing at the sky. Great for bird watching but nothing else!
I tried to reset the position, re-programme the setting my holding the memory button but to no avail. All the drains around the car are clear, door cards are clear and water does not seep inside the car in any place.

Suggested it may be the SAM module but not sure?

Q2 - Rumble at 70mph+
When driving on the motorway, with my foot on the accelerator pedal the car drives normal. At 60 Mph the car is fine, take my foot off the pedal and its sounds OK. When driving at 70mph and ease off the pedal you can hear a distinct rumble noise coming from the car. The rumble lasts until the car reduces its speed to 60mph ish. I cant really pin point the area the rumble is coming from but hazard a guess its near the front of the car.

Tyres are new, replaced them with the same Conti Sports in November 2019. have only covered 3k miles in them but the problem has only just occurred.

Steering wheel does not vibrate nor does the gear stick.

Could it be the Wheel bearings? not had these adjusted yet

Q3 Rough idle
Each morning, when starting the car, the car sounds rough and the idle is, well, really rough. if you press the accelerator pedal to steady and get to the 1000 rpm the car does not sound rough, sound normal. the coil light comes on and stays on for about 5-10 mins.

when switching the car off, and then starting it about an hour later, the idle is fine and no rough idle so i can only think its related to the first start of the day, irrelevant of the temp outside.

 

[Suhayl Tariq]

Bump..anyone?

 

[malcolm E53 AMG]

Welcome!

Q1 - yes as you suspect the SAM

Q2 - Does sound like a wheel bearing car needs lifting and each wheel checking by rotating by hand, There are a multitude of other checks that can be carried out as it could be anywhere along the drive train or even tyre related or engine mounts

Q2 - probably the glow plug relay at fault this is a known problem area and may explain the rough idling at first start of the day

Hope this helps!

 

[Wighty]

Rumble could be rear differential , maybe check the oil level and condition ?
Glow plug light staying on is glow plug failures , replace them all and the glow plug relay .
I’m sure your Indy will have Star diagnostics to look for any other stored faults

 

[LostKiwi]

Rumble - check your engine and gearbox mounts.
They're hydraulic and can leak all the fluid away once tired.

 

[Suhayl Tariq]

hi all
thank you for the replies!
the SAM Module - found a good video on here https://w220.ee/Door_control_module to remove the cover. although the passenger side mirror is the one that is playing up, do i change the SAM Module in the drivers side - or is there 1 module that controls both sides? (logic would dictate that but not sure)

with the rumble noise, i have another observation - when starting in the morning and driving at low speeds, the car makes the grumble noise - like the gears want to change up/down but give up. I think its coming from the gear box area - im guessing its possibly the torque convertor?. I'ts a very similar noise to that at 70mph

The car has never had a gearbox oil change before so will be booked in to get that changed. Get them to look at the wheel bearings too

Glow plugs - any chance someone can tell me (or point me in the right direction) for the merc part code? i assume they use the bosch ones?

thank you

 

[LostKiwi]

As before check engine mounts.

 

[Suhayl Tariq]

Thanks. I’ll add that to the list of checks too

 

[Suhayl Tariq]

hi

had the car back

flush and change of fluid of the gear box - the gears change smooth and drives is so much better!

there is a slight rumble noise but ever so slight. i was told the gearbox mounts looked ok and to drive the car for a short time before committing to changing the mounts

glow plugs - all but 1 were faulty. had them all changed and no more erratic idle!

for the SAM module i had the part number and ordered a second hand one from Dronesfiled. Found a youtube video to remove the section and will give this a go on the weekend

thanks for your help, will keep you posted!