Wind causing instability at motorway speeds. W202.

[JohnnyW202]

Picked up a W202, that seems very unstable at high speed 70+mph.

The steering is overly light i.e a tiny bit of movement makes the car move sharply between lanes, the car is also effected badly by side winds needing small constant corrections.

The car has recently had both the front and rear springs replaced due to being paritally snapped and corroded.

According the the Service history, the Passenger side front ball joint has been changed, along with the steering damper.

Although it have cheap federal 195/65/15s on the back.

And Continental Premium Contact on the front.

6J Steel rims.

Any advise.

 

[gIzzE]

This sounds exactly like a BMW with mixed tyres on front and rear.

Some Mercs are the same.

Can you borrow a set of wheels from someone to test??


If not I would buy a pair of used Continental Premium Contacts off ebay and stick them on the rear.

 

[GSD]

Could definitely be the tyres I had a similar problem with my old winter alloys found out that all the tyres were a different brand and two of the alloys were buckled

It would be good if you can borrow another set of wheels for testing or you could try switching the fronts with the rears that may make a difference.

 

[noogieman]

might be good doing a 4 wheel alignment.
might remedy your problems?

 

[JohnnyW202]

My father had a problem when cheap tyres were fitted to the rear of his LS430.

Prior to this C class I've only had one rear wheel drive car, a 190E.

I assume these cheap tyres have a soft tire wall and not alot of compliance much like his, making for a "floaty" effect from the back end? and needing constant correcting at motorway speeds.

I'll change the tyres over the rears have nearly had it... Part Worns... Kicking myself as my Avensis has two brand new BF Goodrich on the front, but they're 195/60 where as my Merc is 195/65... I'm going to get some nice alloys put on this car as well as the body work, because mechanically it is truly smashing.

Going to change the ATF fluid as well...

Really love the W202, Much like my W201 but with more toys and comfort. Shame about the paintwork :/

 

[pimpmyc250td]

had similar on mine, found two left tyres were down on pressure...

pumped back up much more solid michelin energy all round...

 

[moonloops]

Wind causing instability at motorway speeds

Cut out beans and Brussels sprouts

 

[The mallard]

When a certain Scottish police force started using W202's they began with a C280 which was rock solid, they then got a couple of C230 kompressors as they were allegedly more economical, however both were seriously unstable at Motorway speeds and above, exhibiting uncommanded lane changes etc, MB boffins crawled all over them, changed springs, wheels, dampers removed light bars etc but never managed to fully cure the instability. If I recall they ended up being used in urban areas and not on A class roads or motorways.

So I suspect you may have problems resolving it. Post the reg number and I will tell you if it is one of the offending vehcles?

 

[JohnnyW202]

S159 AET, is the Reg number.

 

[andy27168]

Hi,
I had exactly the same issues with my C230K, when i bought it at 24500 miles and 4 years old.
I was always told that it was a "characteristic" of the car.
At 120,000 miles i hapened to have a "proper" 4-wheel alignment check when i had new tyres fitted, this transformed the car totally, no more instability at speed, it was a lot more willing to straighten up from lock, it turned out the adjustment on the rear was out (toe in/out i think).

 

[The mallard]

Not one of their numbers but similar age. I know it had the MB techs mystified, and they never resolved it. The force bought some C203 320's afterwards, probably got a good deal as compensation. The 202's were apparantly very reliable though

 

[JohnnyW202]

Right changed over the tyres.

Well fitted some alloys off a W203... 220CDI

They have newish 5mm+ Goodyear NCT5's on which I've used before on an Octavia, so I know a good tyres..

Still the problem persists..

If I take it down a country road enthaustically and hit a bumpy patch at 60, the front and back end seem to bounce for a moment and take awhile to recover. my 140,000 Avensis dealt with this better and that was an estate with shocks more worn than this.

I wonder if I don't have the front spring I replaced in properly although it seems to be sitting in the perch rubber and bottom groove fine it seems to be bowing outwards in the middle.

I've checked, the spring is the same length and the snapped original that came out.

Any ideas... I've heard these are slab sided cars, but this is ridicious considering my 190E was lighter and much the same as held the road like glue!

 

[gIzzE]

Sounds like the dampers are shot?

 

[fuzzer]

Yeah , that sounds like the shock absorbers are gone.

Have you tried the bounce test when stationary?

 

[wheels-inmotion]

Very unlikely this is a geometric problem because there's an initiation point for the complaint.

Personally i agree with other members and feel the problem is the dampers unable to control the coil rebound, this would also have a longitudinal effect if all the dampers are ..... Tired.

 

[JohnnyW202]

So what you're saying is Mercedes aren't very good?

Since I've had a Mondeo, Octavia, 406 etc etc... All with over 100k on in fact the Octavia had 207k on when it was finished.

None needed new springs, shock absorbers etc.

Yet this car has done 85k, one owner, FSH and yet it's had 4 new springs, a steering damper, ball joints etc etc.

I know it's down to how a cars driven but I had no problems with my W201!

By the way, the car bounces fine... tried all 4 corners, so would definately pass an MOT, seems a strong recoil back too.