B Class W245 fuel economy and slight wobble

[B160 Petrol]

Hi guys

This is my first post.

I’ve just recently purchased a B Class W245 B160 CVT with full main dealer service history 10 plate. I purchased the car privately not trade.

My first issue is that there is a slight wobble (not a shudder or vibration) it’s a side to side movement when I drive between 10 to 20 MPH, then the car is fine no vibration on the steering wheel, the wobble is coming from the footwell and centre console. I’ve had this checked out and have been told is offside driveshaft but I’m not convinced. The wobble does not happen when the car is cold you have to drive it 5 or 10 minutes for it to start.

The second issue is the fuel economy, I’m getting 18-20MPG AT BEST, it’s local city driving mostly but I would have expected between 28-30MPG figures.

What I have done to try and rectify both issues:

1. New main dealer Spark plugs
2. All 4 new tyres grip grade A and fuel economy grade B.
3. Main dealer Air filter.
4. Had all alloys checked for and buckles for the a slight wobble.

Diagnostic shows now error codes

I would appreciate any suggestions.

Thank you in advance for looking at my post.

 

[Fununcle]

Depending on your in town driving,ie lots of traffic, lots of stop start, I think you’re fuel consumption could be about right.

 

[B160 Petrol]

Depending on your in town driving,ie lots of traffic, lots of stop start, I think you’re fuel consumption could be about right.

Thank you for the quick response, I was getting 17.5 MPG on my Land Rover Discovery 3 doing the same local runs, that was a 2.7 V6, surely the B Class would do a little better this 18-20MPG cant be the right.

 

[Fununcle]

Looking at other posts on here it seems that big Diesel engines and small petrol ones do roughly the same mpg, as you are finding and I see the same sort of thing in my c180. Anything from 18 to 28 mpg in town depending on amount of traffic etc.

 

[Benzowner]

I have a B180 diesel W245, my wheel wobble is at 28-30mph, had it for a number of years. I have new alloy wheels, new tyres, all steering checked and certainly no problems at any other speeds. I have even let go the steering wheel and the car goes straight. I have mentioned it at the last 2 services and nothing found. I have the impression it could be a slight fault in the power steering, but nothing shows other that the very slight wobble.

 

[B160 Petrol]

I have a B180 diesel W245, my wheel wobble is at 28-30mph, had it for a number of years. I have new alloy wheels, new tyres, all steering checked and certainly no problems at any other speeds. I have even let go the steering wheel and the car goes straight. I have mentioned it at the last 2 services and nothing found. I have the impression it could be a slight fault in the power steering, but nothing shows other that the very slight wobble.

Thank for you reply, my wobble is in the footwell and centre console, no issues with the steering wheel. No wobble, vibration or shudder felt in the steering.

 

[BlackC55]

I'm pretty sure it will be a drive shaft or CV joint issue. I have just cured one for this problem on a 245 by fitting a new front left CV joint. Not the first one I have done either.

 

[B160 Petrol]

I'm pretty sure it will be a drive shaft or CV joint issue. I have just cured one for this problem on a 245 by fitting a new front left CV joint. Not the first one I have done either.

Thank you for the info, I will get them checked out

 

[B160 Petrol]

I'm pretty sure it will be a drive shaft or CV joint issue. I have just cured one for this problem on a 245 by fitting a new front left CV joint. Not the first one I have done either.

Are you based in Birmingham or can anyone point me in the right direction to a good garage that can 100% diagnoses the problem and fix it. I’m getting silly quotes of £180 for 3hrs just to have a look and diagnose the problem and extra to fix it.

If anyone knows of a good honest mechanic or garage that can help me it will much appreciate.

Thanks

 

[grober]

Only other possibility might be worn engine mounts allowing movement at a certain resonant frequency. Difficult to diagnose for certain. Do you see excessive engine movement on start up? You probably need to see several other B160's starting up to compare. That's where an experienced Merc Specialist knows what's normal on these cars. I would go with BlackC55's advice as the most likely cause of your problem.

 

[B160 Petrol]

Only other possibility might be worn engine mounts allowing movement at a certain resonant frequency. Difficult to diagnose for certain. Do you see excessive engine movement on start up? You probably need to see several other B160's starting up to compare. That's where an experienced Merc Specialist knows what's normal on these cars. I would go with BlackC55's advice as the most likely cause of your problem.

Thank you for the advice, I just need to find a Mercedes specialist in Birmingham that isn’t going to rip me off.

 

[B160 Petrol]

New symptoms on this cold day, there is a slight creaking noise at full lock right and the front right makes a slight knocking noise when going over a ramp or a pothole. Still looking for a garage.

 

[grober]

Broken front spring or worn strut mount ?

 

[B160 Petrol]

I'm pretty sure it will be a drive shaft or CV joint issue. I have just cured one for this problem on a 245 by fitting a new front left CV joint. Not the first one I have done either.

*****update****

I went to a company called Ultimate Recons in Birmingham and they specialise in driveshaft, CV joints and steering racks reconditioning, they said it’s not the cars driveshafts, no play in them and no grease leaks or ripped boots.

They suggested possible gearbox issues and that’s something I’d need to get checked out, unfortunately they don’t specialise in gearbox issues.

Does this sound right?

The car has full main dealer service history and the previous owner did change the gearbox oil, filters.

I hope it’s not the gearbox!!!

 

[B160 Petrol]

Broken front spring or worn strut mount ?

Had springs checked and all look fine

 

[grober]

Had springs checked and all look fine

Sometimes its difficult to spot a broken spring if its at the coil end- just saying. Try the "static rock test" if you can. Get two hefty assistants to rock the car on it suspension while you try to locate the source of the noise /detect excessive play in the supension but be sure not to get any body part caught in the process!

 

[MickyP64]

I’ve just had the drive shaft and inner CV joint replaced on my A200T for symptoms that sound very much like those that you describe. I had an intermittent creaking/knocking/clunking sound that appeared to be coming from the front RHS of the car that got progressively worse over time, and then after a while a very noticeable wobble that would come and go at various speeds. All good now!

I had various garages have a look at it over a period of about 12 months, all had a good look but not one of them diagnosed the drive shaft/CV joint, only when it became unbearable and I took it to a highly recommended A Class specialist did I get it resolved. The wear was such that the turn of the drive shaft had become concentric, and so resulting in the 'wobble', weirdly the symptoms would come and go, but were most evident under acceleration.

If it's CVT I doubt it's the gear box - I've had plenty of problems with my CVT over the years, none of them have been noise or wobble related.

 

[B160 Petrol]

I’ve just had the drive shaft and inner CV joint replaced on my A200T for symptoms that sound very much like those that you describe. I had an intermittent creaking/knocking/clunking sound that appeared to be coming from the front RHS of the car that got progressively worse over time, and then after a while a very noticeable wobble that would come and go at various speeds. All good now!

I had various garages have a look at it over a period of about 12 months, all had a good look but not one of them diagnosed the drive shaft/CV joint, only when it became unbearable and I took it to a highly recommended A Class specialist did I get it resolved. The wear was such that the turn of the drive shaft had become concentric, and so resulting in the 'wobble', weirdly the symptoms would come and go, but were most evident under acceleration.

If it's CVT I doubt it's the gear box - I've had plenty of problems with my CVT over the years, none of them have been noise or wobble related.

Thank you for your reply I will update once I get another garage check the driveshaft out.

Just out of interest what issues have you had with your CVT? This is the first CVT AUTOMATIC I’ve ever had and it scares me with all the stories I’ve heard and the bills people have paid.

 

[MickyP64]

I used to be like that too but I don’t really care anymore, I used to drive around almost expecting the gearbox to fail at any moment after all the bad news I was reading. There's loads of these cars on the road and they're not all suffering from gearbox failure.

Issues with the speed sensors seems to be the most common problem. They’re located within the ECU in the gear box and they go open circuit – the car then has no way of monitoring what the gearbox is doing so it goes into ‘limp home mode’. The problem usually manifests itself intermittently and can often be temporarily resolved by turning the ignition off and then back on again. There’s loads of info about this all over the internet now and it's not just MB that suffer from it. You can get it fixed by either sending the ECU off for repair, or alternatively MB now sell a repair kit (replacement speed sensors) – both options cost around £400. I had this problem but got it fixed under dealership warranty, at the time the only option was a new valve body together with the new ECU at a cost of around £1500 (luckily I didn't have to pay on this occasion).

If you’re really unlucky and have a mechanical failure then it can be expensive, I’ve had this too and had the gearbox rebuilt for £2400, but I haven’t seen many posts regards the mechanical failure that I had (primary pulley shaft/bearing wear – caused the whole mechanism to lock up - I had quite a detailed post hear on this forum with pictures but it seems to have disappeared so I can’t link to it).

I read lots of posts slating the CVT and they’re probably quite reasonable comments, but you know I see plenty of other posts related to gearbox issues with plenty of other more ‘respectable’ MB models too.

I think it’s just best not to worry about it until it happens or if it happens. If you’re unlucky enough to have a major failure like the one I had I guess it comes down to how much you like the car and how much you’re prepared to spend. I figured I’d have to spend quite a bit more than £2400 to get a replacement car that I liked (it still stung though!).

 

[B160 Petrol]

I used to be like that too but I don’t really care anymore, I used to drive around almost expecting the gearbox to fail at any moment after all the bad news I was reading. There's loads of these cars on the road and they're not all suffering from gearbox failure.

Issues with the speed sensors seems to be the most common problem. They’re located within the ECU in the gear box and they go open circuit – the car then has no way of monitoring what the gearbox is doing so it goes into ‘limp home mode’. The problem usually manifests itself intermittently and can often be temporarily resolved by turning the ignition off and then back on again. There’s loads of info about this all over the internet now and it's not just MB that suffer from it. You can get it fixed by either sending the ECU off for repair, or alternatively MB now sell a repair kit (replacement speed sensors) – both options cost around £400. I had this problem but got it fixed under dealership warranty, at the time the only option was a new valve body together with the new ECU at a cost of around £1500 (luckily I didn't have to pay on this occasion).

If you’re really unlucky and have a mechanical failure then it can be expensive, I’ve had this too and had the gearbox rebuilt for £2400, but I haven’t seen many posts regards the mechanical failure that I had (primary pulley shaft/bearing wear – caused the whole mechanism to lock up - I had quite a detailed post hear on this forum with pictures but it seems to have disappeared so I can’t link to it).

I read lots of posts slating the CVT and they’re probably quite reasonable comments, but you know I see plenty of other posts related to gearbox issues with plenty of other more ‘respectable’ MB models too.

I think it’s just best not to worry about it until it happens or if it happens. If you’re unlucky enough to have a major failure like the one I had I guess it comes down to how much you like the car and how much you’re prepared to spend. I figured I’d have to spend quite a bit more than £2400 to get a replacement car that I liked (it still stung though!).

Thank you for the reply at least I know what to look out for, if something doesn’t seem right.