Rattle coming from under my B Class

[MB-BTurbo]

Oh good grief. Are you still benefitting from nice courtesy cars?

Have you been able to test drive another B class to compare and to hear these 'rattles' from these cars as well? Im around 40 mins from you (Keighley) a bit far to pop over but if they are still selling the 'its a characteristic' nonsense Id be happy to meet halfway in Bradford for example and you can compare mine to yours.

 

[ccp]

The courtesy cars have dried up for now - and they weren't particularly nice. All two(ish) year old A class classics, one with bald tyres, another with a faulty radio, and a third with dodgy brakes. You couldn't make it up!

One point I think you may have missed - the car in question is an A150. I understand / believe that the A & B class engine & transmission designs are very similar.

Thank you for the offer to meet - I work in Bradford (Huddersfield side) and would be happy to meet you nearer home, assuming you agree it would be worthwhile. But as the MB dealer is still engaged (for now) I would like to play this path out and see where we end up - also we don't have the car at the moment either!

I'll post again when I have more news!

 

[MB-BTurbo]

One point I think you may have missed - the car in question is an A150.

Sorry Im confused. I thought it was a B class that is making the noises?

 

[paulandlouise]

I am taking my car in next Thursday but after reading the thread am not confident but it does sound like the same noise - mine happens between 1000rpm and 1400 rpm and is most noticeable first thing in the morning on start up - but then has started to make it now during the day when at idle or when moving slowly in the car - I even out my iPhone under the car yesterday and recorded the noise so I have evidence it does happen - spoke to Mercedes and the service manager will come out with me - def not a normal noise as didn't do it for the the first 18 months !!!!! Will watch this thread with interest and update myself when I have been in .

 

[paulandlouise]

Hope I am not confusing things for everyone - mine is the B Class 160 sport auto - With the rattle !!! And yes I do believe the A and B class as far as I am aware share a lot of components so fingers crossed once your A class is fixed then I will have a way forward with mine - the comments about a piece of the honeycomb inside the catalyst breaking off and rattling does sound feasible for me and I believe they are prone to this looking around the Internet - I can't believe when I tell em that it's under the car and record the noise for them from under the car they still persist in looking in the engine bay - maybe they don't want to pay for an exhaust / catalyst....I will await your update.

 

[MB-BTurbo]

I am taking my car in next Thursday but after reading the thread am not confident but it does sound like the same noise - mine happens between 1000rpm and 1400 rpm and is most noticeable first thing in the morning on start up - but then has started to make it now during the day when at idle or when moving slowly in the car - I even out my iPhone under the car yesterday and recorded the noise so I have evidence it does happen - spoke to Mercedes and the service manager will come out with me - def not a normal noise as didn't do it for the the first 18 months !!!!! Will watch this thread with interest and update myself when I have been in .

My shock absorber did this. The oil in the shock had burst and was noticeable when starting. As the car was driven it sounded as though the noise went slightly - maybe due to the oil moving around or does it get warmed up??? I dont know but eventually it was bad all the time and had it replaced.

 

[MB-BTurbo]

Interesting stuff. (I need to get 30 posts in order to use private message)

Lol, I see what you're doing. You can reply to this if you want, that might help.

 

[ccp]

Sorry Im confused. I thought it was a B class that is making the noises?

No it is me that is mixing things up - I trawled the forums for reports of similar symptoms and the OP for this thread (paulandloiuse) had posted a description that made me think it might be a similar problem to mine.

My car with the rattle is an A150,the OP's is a B160 - As far as I am aware the engine and exhaust are pretty much the same - obviously the gearbox is different because mine is a manual and the OP's is an auto. If paulandlouise can PM me the VIN from their B160 then I'll compare the major components in the MB EPC software to check out this belief.

 

[ccp]

My shock absorber did this. The oil in the shock had burst and was noticeable when starting. As the car was driven it sounded as though the noise went slightly - maybe due to the oil moving around or does it get warmed up??? I dont know but eventually it was bad all the time and had it replaced.

The noise you experienced with your shock absorber - how did you make it happen? did it require you to be driving along causing the suspension to work or did it happen when stationary and bouncing the car at the relevant corner?

 

[ccp]

Todays update - no delivery of parts to MB dealer today so car returned to us whilst the exhaust parts are located!! It will probably go in for the exchange early next week.

The noise (with the original exhaust components) is now worse than ever - While we wait for MB to sort their act out I'm going to try and record the noise and post it for others to hear and comment on.

 

[paulandlouise]

Hi - I was sat listening to my rattling B Class today and thought I would turn the air con off to hear the noise better as it was a warm day and unbelievably the rattle disappeared !!! - I altered the revs to compensate for the fact that it changes when the air con is switched on and off and The noise stayed away - turned the air con back on and the noise came back? However and this is where I am confused - if I leave the fan on but press the A/C button so I have fan but no air con the noise stays hmmm... I originally thought may be air con compressor but unless that works even when the air con button is off I am completely baffled..
The noise comes a lot first thing in a morning so going to mess about with the air connect then - unless it's just coincidence with the revs changing ...will report back tomorrow ..any views ?

 

[paulandlouise]

Well maybe there was something in my thoughts re the air con - my car went into Mercedes today and there chief technical engineer came out , listened to the car and then I emailed him the noise I recorded so he could listen to it with his technical team... He said the noise was normal and was belt chatter from the belt that looks after the air con , alternator etc ( not the cam belt) ... I continued to say that the noise should not be there on a 23k car and they needed to sort it and off I went .... On my return they had replaced this belt and assure me that was the cause - - certainly no noise was there on the way home but tomorrow morning will be the big test ...will report back then.....

 

[joecash]

these dealers should know xx after all they charge virtually charge the same hourly rates as solicitors xx no such thing as mates rates xx

 

[polo_dude]

Well maybe there was something in my thoughts re the air con - my car went into Mercedes today and there chief technical engineer came out , listened to the car and then I emailed him the noise I recorded so he could listen to it with his technical team... He said the noise was normal and was belt chatter from the belt that looks after the air con , alternator etc ( not the cam belt) ... I continued to say that the noise should not be there on a 23k car and they needed to sort it and off I went .... On my return they had replaced this belt and assure me that was the cause - - certainly no noise was there on the way home but tomorrow morning will be the big test ...will report back then.....

How are the morning rattles now? Any news on this?

 

[paulandlouise]

How are the morning rattles now? Any news on this?

Morning rattles are still there unfortunately even though they assured me it would be gone - at a complete loss now - the service team don't seem to have any idea apart from saying - " they all do that" to which I point out - " we'll it didn't for 2 years " ! What more can I do - I recorded the noise for them and no one seems interested any more - a shame really first time I have ever owned a Mercedes having had Renaults for the last 20 years - never missing a beat - - am open to ideas if anyone can help ?

 

[MB-BTurbo]

Have you tried another dealership for their opinion?

 

[paulandlouise]

To clarify the noise is a definite rattle - a bit like a piece of plastic trim resonating but loudly - it does it most first thing in a morning when backing the car out of the garage or starting to pull off- I can replicate it by putting the hand break on whilst the car is in gear and pressing the accelerator until it reaches a certain point then the rattle starts - its coming from underneath the car a little bit forward from where the bonnet ends and the front door starts but if I look underneath I can't pin point it - then even though I don't move my foot from the accelerator the noise dies off itself slightly- Then when it pulls away it rattles for a brief couple of seconds . The only fly in the ointment is it doesn't only do it in a morning ? But can do it at other times - am so fed up with it . Where do I go from here ? I cant hear it when I am driving though ??? The noise does seem to go though as I have mentioned before when I turn the fan off but that may be to do with the revs changing slightly .

 

[paulandlouise]

Don't really have another dealer really close and they always want it for the day - but maybe I'm gonna have to bite the bullet and travel as its so frustrating .

 

[MB-BTurbo]

i cant think of much else Im afraid. Ask around and see if there are any other mechanics around your area who dont charge if they cant locate a fault. I have had to take my car to 3 places before my knock was found. My normal garage gave up after spending 2 hours solid on it. They didnt charge me - although its probably because Im a good customer (or rather - a regular customer since having my B class).

Mercedes misdiagnosed it and only realised after I spent £200 on parts that they said "was" wrong. Then took it to a different garage. The guy spent 2 hours more got nowhere, asked his colleague who found it in 5 mins! They charged me for 3 hours though so not happy but could be bother to argue especially as the fault only cost £20 in parts and they were the ones to find it.

 

[paulandlouise]

Problem solved !!!!! Only after I insisted in going into the workshop and having the car raised and standing under it with a mechanic ( after it had stayed over night as it was worse when the engine was cold ) did the mechanic and service advisor go " oh that noise " - anyway the problem was caused by the tensioner spring for the belt that looks after the air con , alternator etc - it's hidden away in the side of the engine - you can't see it - he identified it was that by putting a spanner on a nut near the belt and holding it tight and the noise went - what I would say is they told me it was an engine out job to replace and took a day !! But it's back now and silent - all under warranty thank goodness - well accept for I now have a rattle coming from the battery compartment under the floor - cant see where but I can live with that as the loud noise has now gone - the moto has to be "never give in !! Even though it took me 3 months to get it resolved !!!