Wobbly Mercedes ML164

[RINMOS]

Hi,
I love my old Mercedes ML (2008 320CDi) but driving it on our now useless roads has become a challenge!
It wallows up and down and tramlines and basically gets thrown off-course by pot-holes and sags
in the road. Does anyone else suffer this problem? Ive had the wheels aligned, straightened, re-aligned,
changed tyres (Pirelli Sport Contacts now and no better than the cheaper Scorpions it had on before).
I met a lady with a similar year ML having her tyres changed and she said its like hanging on to a wayward
horse.
I'm going to send it to the knackers yard if it carries on misbehaving unless someone out there can
recommend remedial action?

Edited by RINMOS on Friday 2nd February 19:56

[E90_M3Ross]

On a 15-16 year old car then you need to look at all of the suspension components as they'll be well past their best.......shock absorbers, springs, top mounts, bump stops, all arms and bushes, subframe bushes etc as well as the condition of all of the steering system.

You can spend a lot of money on a full suspension refresh, but it can drive literally like a new car.

[RINMOS]

Thanks E90_M3Ross,
Would have replied earlier but as a "newbee" I was not allowed by the system
in case I increased the amount of "SPAM" on the site for established floks like yourself (yeah... I know).
Seems like a long and expensive haul to get back to where the car should be. Food for thought...
R.

[Gigamoons]

E90_M3Ross said:

On a 15-16 year old car then you need to look at all of the suspension components as they'll be well past their best.......shock absorbers, springs, top mounts, bump stops, all arms and bushes, subframe bushes etc as well as the condition of all of the steering system.

You can spend a lot of money on a full suspension refresh, but it can drive literally like a new car.

Exactly that. SUVs are heavy and 15 years will be considered a fair lifespan for these components within OEM design principles.

At this age cars start falling into 'refresh territory' or 'MOT failure territory' depending on how interested the current owner is in keeping it going or limping it along for a bit before just chopping out of it and buying something newer.

[Fiedka]

Whole suspension refresh aside, your symptoms sound remarkably like shock absorbers just went.
Bad shocks will also amplify any play in other areas of the suspension.
I would start with those.

[Hustle_]

RINMOS said:

Ive had the wheels aligned, straightened, re-aligned,
changed tyres

All that's very good but it's a 16 year old car and there is absolutely nothing in there to remediate the tired suspension. I agree that shock absorbers are probably part of the issue but there are also a dosen or more bushes and balljoints under there which, if worn, will introduce an element of play and undo your good work on the geometry.

[RINMOS]

Thanks Fiedka. This weekend I noticed the car did "crash" into some pot-holes and
that makes sense. The shocks will be replaced first!!
Fair comments about the age thing too G. That ML weighs over 3 tons so its certainly
time to call time on the suspension. R.

[akirk]

RINMOS said:

Seems like a long and expensive haul to get back to where the car should be.

Why is it a long and expensive process?
not especially long - throw into garage and then collect car
expensive if viewed in isolation, but a lot cheaper than scrapping the car and buying one ten years newer which handles better yet already is 5-6 years into the same cycle of eventually needing new suspension...

Suspension parts are consumables on a car in exactly the same way as tyres / brakes / etc. - they tend to last longer, but they still degrade over time...
I have a 30yr old range rover which has had new shocks / new bushes / various new bits I don't understand and even new airbags at each corner (fortunately very cheap on that era RR) - drives better over Bristol roads than the 25years newer F-Type I owned...

[RINMOS]

Point well taken H.
Thanks everyone with your positive encouragement to make some remedial changes. R.

[Hustle_]

Should probably add that I know nothing about MLs in particular but given your anecdote with the lady ML owner, there is a possibility that they're just 'a bit like this' and you might end up throwing a lot of money trying to make a Clydesdale do dressage.

Did it used to behave better?

In a similar vein, maybe someone out there knows some tricks to make an ML drive better. Maybe it needs a bit more toe-in at the front than spec or something.

[RINMOS]

"... a lot cheaper than scrapping the car and buying one ten years newer which handles better yet already is 5-6 years into the same cycle of eventually needing new suspension..."
Indeed Akirk.

[E90_M3Ross]

If doing the shocks you really may as well do the springs, too in my opinion.

[Gigamoons]

I’d start by getting it into garage I trust, explaining the issues, getting it up on the ramps for inspection and getting their view on what the immediate priorities are to get sorted.

[Hustle_]

E90_M3Ross said:

If doing the shocks you really may as well do the springs, too in my opinion.

and top mounts

[RINMOS]

OK, I will start with Shocks and Top Mounts and I will keep you guys informed!!
Cheers, R.

[Hustle_]

TBH I think Gigamoon's reply is the best approach. Let a mechanic inspect and diagnose- although yes, it is likely you'll need at least a couple of shock absorbers along the way.

Gigamoons said:

I’d start by getting it into garage I trust, explaining the issues, getting it up on the ramps for inspection and getting their view on what the immediate priorities are to get sorted.

[RINMOS]

But why the tram-lining?
If there are longitudinal ruts in the road or "troughs" on the motorway... the car
will follow them. Crossing the white lines and the car will try to follow them too!!
Naughty thing it has become!

[8bit]

Hustle_ said:

E90_M3Ross said:

If doing the shocks you really may as well do the springs, too in my opinion.

and top mounts

Good chance the springs need attention as well, these cars have an appetite for them. We had three go on our old W164 ML320 in the few years we've had it. I've only ever had one broken spring on all the other cars we've owned put together (maybe just been lucky there).

To be fair though, ours was fairly "marine-like" in terms of handling, as I would describe it. Definitely get it properly checked out but yours doesn't sound terribly unlike ours was, OP.

[RINMOS]

Thanks 8bit... yeah "Marine" describes it well !!
I did take it to a garage (Merc in Berkhamstead) and they pronounced it fit.
I took it to Merc in Reading for a full geometry check. They did their thing but it did
not solve anything. Hence my reaching out to you guys.
I will focus on a systematic remedial process... starting with Shocks, Springs and Top Mounts.
Will keep you posted! R.

[Hustle_]

RINMOS said:

But why the tram-lining?
If there are longitudinal ruts in the road or "troughs" on the motorway... the car
will follow them. Crossing the white lines and the car will try to follow them too!!
Naughty thing it has become!

If it isn't due to bad toe settings (which you have checked) it is probably the toe wandering around because of some combination of worn inner or outer tie rods, worn front track control arm bushes, or rear links, rear trailing arm bushes etc- e.g. parts responsible for controlling the toe and preventing it from varying excessively.

If it feels like it's steering itself, it quite probably is!