Car's going home...

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Burger

Active Member
Joined
Sep 13, 2010
Messages
862
Car
2007 SL (R230)
Setting off for Germany at 5.00am. Going for the week to escape the event of the year... oops, I mean visit the parents in law. Really looking forward to getting the SL on some smooth roads and letting it breath a little. Unfortunately the weather forecast isn't as sunny for there as it is here, but hey, what do they know? :)

Just had the 4 years service done and two new rear tyres fitted so hopefully it'll be smooth running all the way.

Regards,
 
Have a safe trip Dave... and enjoy the trip :).... or at least the journey there and back.
 
The trip is almost at an end and it's been absolutely wonderful driving on the smooth quiet Tarmac of mainland Europe.

One thing though that I'm a little concerned about is the level of final drive noise I can hear in the SL. I say final drive because it's directly related to road speed and sounds like a low pitched mechanical hunting noise. Wheel bearing? Prop shaft? Diff? I hear it most between about 40 and 70 mph. It also seems to be worse after a fast drive.

Strangely though it seems to vary at times which makes me wonder if it could be tyres and road surface. I just had new Michelin Pilot 3's fitted to the rear though so can't be sure.

I know noises are hard to describe and diagnose without hearing them but any ideas? Car's just done 20k and just had it's 4 year service.
 
Not sure if anyone's reading this or even interested or maybe this iPhone app doesn't work?

Set off the journey home today and had only gone 20 miles when the car cut out momentarily, the dash lit up then it restarted leaving me with an engine management light and a red battery warning. Apart from these it seemed to be running fine. Detour to nearest mb dealer and they diagnosed the crankshaft sensor. They didn't have one in stock but took one off another SL they had in for some work.

The cars still making the same whiny rumbly road speed noise. Will get it checked when we get back.

Regards
 
Reading it and enjoying it too.

Really chuffed the Mercedes dealer got you on your way. Give them a plug, why not.

Safe journey home.

CHEERS
 
Reading with interest too, sounds like that MB dealer deserves a thumbs up mention, we are always happy to mention 'stealers' by name when it goes wrong so give em a good news story! :D
 
The dealer is Autohause Hahn just off the E51 at Munchberg. When we arrived they took the car straight into the workshop and read the fault in 10 mins. Then realising they didn't have one in stock phoned other dealers on our route to see if they did. None did and so then plan B taking one off another car and order in a new one for them saw us all fixed in 45 mins. 50 Euros seemed like a good deal.

We finish the journey home today and so far the cars been fine with the second hand sensor. I am though worried about what seems to me to be excessive final drive noise.

Regards.
 
Welcome home Dave.

You can now sort the final drive noise at your own pace.

Your signature block says you als have a Dennison GW500 + AVR. At the risk of total ignorance is that some sort of agricultural machine.
 
Welcome home Dave.

You can now sort the final drive noise at your own pace.

Your signature block says you als have a Dennison GW500 + AVR. At the risk of total ignorance is that some sort of agricultural machine.

Not far off eh! Looks like an I pod thing according to google.
 
If you have a noise related to road speed and with a hunt (louder and softer with no changes to the running conditions) then you need to be looking at wheels/tyres, tyre pressures, weight distribution, wheel balance, does it disappear on a motorway bend, lane change, to the right or left? The hunt has got me stumped here, any dif/final drive whine should be constant and road speed related, well it always was on my Renault! Without the hunt it could be wheel bearings, centre bearing if you have one, diff…
 
Arrived home last night all safe and sound and without any further incidents. I'll stick some pictures up from the trip soon.

This noise... much harder, but not impossible to hear in the UK thanks to the increased tyre/road sounds/feels mechanical and not from the tyres... I think I misled you all by describing it as a hunting noise and should probably have said more a rasping/grinding noise... only not so grinding as I think something's going to fall off any second. More like a rough bearing would sound/feel.

It makes no difference at all if the car is driving straight or turning, changing lanes or anything else. Which to my mind rules out wheel bearings and leaves the diff and prop shaft... or perhaps the final drive of the gear box? I guess it could still be a rear wheel bearing, but I'd expect some variance in noise depending on weight transfer etc.

Having said that, I did notice the noise disappears completely when the suspension is unloaded... eg hit a bump at speed - which makes me think once again, wheel bearing.

I can hear the noise as low as 20mph and as high as 80mph beyond which the pitch and increased road/wind noise make it disappear. It is loudest in the car with the roof up and at around 50 to 60 mph. With the roof down or the windows down, I cannot hear the noise being reflected from other objects (walls, hedge rows etc.) and other noises such as wind, tend to lessen it, which makes me think it might just be natural resonance in an SL?

Anyone else with an SL noticed something similar?

I'll be speaking to the dealer tomorrow and asking them to check it out under warranty and will of course post back, but I'm concerned I'll get the 'They all do that sir' line.

Regards,
 
I'll be speaking to the dealer tomorrow and asking them to check it out under warranty and will of course post back, but I'm concerned I'll get the 'They all do that sir' line.

Regards,

Easy , before you mention anything about the noise in your own car , ask for a test drive in a new one , and listen for any noise .

Then , when you mention the noise in your car , if they come back with that excuse , you can point out that the noise is not present in their demonstrator , and suggest they accompany you in both cars if they want to debate it - unless , of course , the demonstrator also makes the noise !
 
The only things remaining that I can think of is the parking brake, perhaps loose shoe/foreign object in there. Alternately a mounting rubber on the exhaust or running gear could have gone bad and is allowing contact under torque, or foreign body bridging the rubber allowing noise transition, are the engine mountings good?

A desperate measure, get someone else to drive and get an arms length if pencil diameter hose with one end to an ear you can get a good idea where the sound is coming from by pointing the other end at suspected areas.

You aren’t a concert musician by any chance? :)

J
 
Just returned from the dealers where, no surprise, they couldn't find anything wrong. The guy who came out with me to listen claimed he could hear the same noise I'm concerned about, but like me at times seemed convinced it was tyres. However, he also agreed they should have a good look because there might be something put back incorrectly after replacing the fuel filter the week before last etc.

As I say he couldn't find anything wrong, although he did apparently re-torque many of the bolts etc. that would have been disturbed on the service.

I'm not disappointed really, more I'm reassured to know there's nothing wrong. The noise is hard to isolate from all the others in this country with our appallingly loud road surfaces, and so I honestly don't know if it existed or not before the trip to Germany... I'm prepared to accept it's a normal noise for the car and will monitor it over the next weeks to make sure it's not getting worse.

The car's only done just over 20,000 miles and right before the trip to Germany I had two new Michelin Pilot Sport 3's fitted to the rear. I can't believe these could be the source of the noise, but perhaps they could be? It had Pilot Sports (not 3's) on before.

Anyway, as I say, I'll monitor it and see if there's any change over the next weeks or learn to ignore it :)

Regards,
 
No change in the noise, but it's still there!!! However, I've now decided that it is absolutely the tyres. This because of variances in the noise on different surfaces etc. and the fact that when unloaded, for a brief moment it disappears completely.

Not happy :(

Brand new Michelin Pilot Sport 3's, £300 each and they're making this odd noise.

My tyre dealer told me the 3's were the replacements for the standard Pilot Sports... Unfortunately, and too late, I've found out this is nonsense. The 3's are a new tyre sure enough but Michelin continue to make the originals.

Oh well, I'll just have to rack up the miles and wear them out :)
 

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