Cruise Control and other things....

[Pookis Dad]

Hi, remember me? I posted ages ago regarding a "C" 200 problem.

Put it to the local dealer who fixed it within a couple of days and charged a mere £440 for the privelage

Problem?

We think the relay went and the previous owner got messrs C Bronson & J Wayne to "have a look".

The result was melted wires and busted relay holders as well as a knackered key.

Going now and boy does it go 140mph (on the track ). Not bad for what my friends call "the baby elephant".....

Anyhoo, I love this car

I changed the rear discs & pads in a little under half an hour per side from jacking up to jacking down.

I also changed the rear bumper in a little under 15 minutes as it was cracked when I bought the car.

Now I feel ready to tackle the cruise control as it has decided to only work up to 40mph

Anything over that and it cuts out as if a cam on the stepper motor has broken.

Before I go stripping the throttle is there anyone had one of these with a similar problem?

It's the 2.0 litre 5 speed auto, 1997 petrol with 142,000 on the clock and it burns no oil.

Another thing is the radiator fan. I don't think it is operating as it should as the fan feels loose even at normal operating temperature. Is this an easy job to change and should I change the water pump while I'm at it?

Thanks in advance.

Pooki's dad.

 

[stringerdavid@hotmail.com]

Cruise Control

Hi there,

I had a similar problem with my cruise control - which is now resolved.

The problem was that of different sized tyres (275/40/20 front and 295/40/20 rear) It was not as simple as the fact that the rears were slightly wider than the front - the rolling diameters were different. This meant that the system 'thought' that one or more wheels were losing traction and simply swithched off the cruise control - or wouldn't allow it to engage at higher speeds.

Worth checking out.

 

[jamesmc]

David

Nice one

Passing on info like this that can save others hours of grief!

 

[stringerdavid@hotmail.com]

Cruise control

No problem.

Let the Forum know how you went on.

p.s. I ended up replacing all 4 tyres with new 295/40/20's all round - just to be on the safe side. Extreme I know - but I am moving to Southern Spain soon, and needed my cruise control to work.!!

 

[Pookis Dad]

Well bugger me, you could be spot on.....however, my car doesn't have traction control. But thats not to say the ABS sensors have picked up the fact the rolling diameter of the rear tyres is different from the fronts.

I got a set of alloys on a Vectra (long story, suffice to say the Vectra is VOR for a long time till the engine is changed) so borrowed them to use on the Mercedes. I noticed the tyres were different sizes. Spookily, when I changed the tyres the cruise control went tits up.

I shall change the tyres soonest as I like using the cruise control, what with living in Inverness and driving down the A9 to Edinburgh needs the patience of a saint.

Thank you very much indeed all.

 

[JEZ.S320L]

Glad to have been of help

Well bugger me, you could be spot on.....however, my car doesn't have traction control. But thats not to say the ABS sensors have picked up the fact the rolling diameter of the rear tyres is different from the fronts.

I got a set of alloys on a Vectra (long story, suffice to say the Vectra is VOR for a long time till the engine is changed) so borrowed them to use on the Mercedes. I noticed the tyres were different sizes. Spookily, when I changed the tyres the cruise control went tits up.

I shall change the tyres soonest as I like using the cruise control, what with living in Inverness and driving down the A9 to Edinburgh needs the patience of a saint.

Thank you very much indeed all.

I couldn't tell you WHICH of the sensors (ABS, ESP, BAS etc etc) and how they interact with each other, that are affected - but as long as all is OK now, thats fine.

These MB's are too damn clever for their own good - Ever get the feeling that the driver is surplus to requirements??

 

[Pookis Dad]

Cruise Control Fixed

Hi guys n gals, I fitted a pair of new tyres to the back of the car and the cruise control is now working perfectly.

I was told that this car didn't "know" what size tyres it had so the cruise control couldn't have stopped because of this.

However, you guys were correct and I can only assume the ABS was telling the ecu that the rear wheels were spinning or something so it shut down the CC.

Damn clever car, and it is 10 years old with 142,000 miles on the clock.

I also replaced the plugs and leads which has corrected the hesitation and made the car a pleasure to drive once more.

My wife is happy so that makes me happy.

Once again, thank you

 

[kid-jensen]

Pooki's Dad,

If you think the Fan is slipping, do a Forum search for "Carrot Test". That should diagnose it for you..

 

[Pookis Dad]

The Fan Is Fixed

I replaced the fan drive along with the radiator.

It was definately useless, no carrots required.....the overheating told me all I needed to know.

I think the overheating caused the radiator to expand, cracking it at the top so it was a case of spend it and fit it.

It no longer overheats and it no longer dumps coolant.

Thanks anyway

 

[JEZ.S320L]

Hi guys n gals, I fitted a pair of new tyres to the back of the car and the cruise control is now working perfectly.

I was told that this car didn't "know" what size tyres it had so the cruise control couldn't have stopped because of this.

However, you guys were correct and I can only assume the ABS was telling the ecu that the rear wheels were spinning or something so it shut down the CC.

Damn clever car, and it is 10 years old with 142,000 miles on the clock.

I also replaced the plugs and leads which has corrected the hesitation and made the car a pleasure to drive once more.

My wife is happy so that makes me happy.

Once again, thank you

It's all to do with the 'rolling diameter' of the different-sized tyres!

Glad you have got it sorted out though - I was just passing on the information from my own situation + information gleaned from this forum.

p.s. - do drivers in Southern England not know what the blooming inside lane is for!!!??? I have just travelled North and South of the M6 - the ONLY time I could click CC on - was on the Toll Road - Grrrrrrrrrrr.
By the way - beware of dark BMW's and/or Volvo's on the Toll Road - they COULD be Police (saw one booking a Toll Road speeder). Which leads nicely on to another point. IF the Toll Road is classed as a PRIVATE ROAD - why does the National Speed Limit apply?

 

[stevesey]

p.s. - do drivers in Southern England not know what the blooming inside lane is for!!!??? I have just travelled North and South of the M6 - the ONLY time I could click CC on - was on the Toll Road - Grrrrrrrrrrr.

Left hand lane is for undertaking BMWs

You were travelling at the weekend - lots of numpties about. Doing the Bristol to Swindon M4 commute regularly I find the standard of lane disipline quite good in the rush hour. Only get to do the left lane -> right lane and all the way back to the left lane overtaking move about once a day.

 

[Pookis Dad]

Toll Road

Ahhh, the M6 toll.

I was on there with the Laguna doing 124mph on cruise control coz it's a "private" road.

Thing is, the Laguna tops out at 124mph on cruise, but will happily tramp on to 140mph on the pedal?

I remember traveling to Southhampton via the toll road and using CC. The car had gone but a couple of miles at 124mph when the CC shut down followed by "Warning, tyre pressure unsuitable for current road speed!" (or something similar). The car had decided that the front tyres being 3 or 4 psi less than the rears it was unsafe to drive.

Damn!

Still, I was uber impressed by the cars ability to tell me what a tit I was for not checking the pressure (even though I knew they were being changed for new tyres when I got home).

Cars, eh?

 

[JEZ.S320L]

Ahhh, the M6 toll.

I was on there with the Laguna doing 124mph on cruise control coz it's a "private" road.

Thing is, the Laguna tops out at 124mph on cruise, but will happily tramp on to 140mph on the pedal?

I remember traveling to Southhampton via the toll road and using CC. The car had gone but a couple of miles at 124mph when the CC shut down followed by "Warning, tyre pressure unsuitable for current road speed!" (or something similar). The car had decided that the front tyres being 3 or 4 psi less than the rears it was unsafe to drive.

Damn!

Still, I was uber impressed by the cars ability to tell me what a tit I was for not checking the pressure (even though I knew they were being changed for new tyres when I got home).

Cars, eh?

I'll start a new thread on this.