BCI Classmaster Mystery Noise Front End.

CQ Transport Man · Post by **CQ Transport Man** » Mon Jul 16, 2012 9:09 pm

http://www.youtube.com/watch?v=udtTs41KsV0 The Bus Photo & Sound of the problem. The youtube tab would not show Video. Thanks

Hi. I am the Driver of a 57 Seat BCI Classmaster. The company and I have been trying to Diagnose the noise coming from under the front end of the coach, All the Steering & power steering has been checked, brakes to bearings & Axle, airlines to tanks & airbag. What puzzles is. No air leaks, the air meters do not alter when the sound goes off, It starts above 20kmh and drops out below 20kmh, as in the sound. When it hits a pot hole or when the coach tilts to one side or another. Or when the steering wheel is adjusted, the sound can stay when or how long it wants or it just dissapears. BCI Australia is mystified by the sound, but reckons 2 other coaches in Oz have had the problem and never found the problem. Sounds like a dragging cat to death sound. They have reckoned it maybe stabilizer valves such stuff who knows. But when it is really wet underneath the front end, sound dissapears for a few days. Mystery. Anyone else experience this sound or have heard it? Anyone have a solution? To passengers it's off putting and driver keeps getting ??? Whats that sound, Anyone have answers would be good.

http://www.youtube.com/watch?v=udtTs41KsV0

Trevor 062 · Post by **Trevor 062** » Tue Jul 17, 2012 12:10 pm

Probably just another Illegal immagrant under there who maybe gets sea sick..

mrobsessed · Post by **mrobsessed** » Tue Jul 17, 2012 4:25 pm

That sounds like an air valve. Does it happen when you're stationary as well?

Busman444 · Post by **Busman444** » Tue Jul 17, 2012 5:22 pm

CQ Transport Man wrote: It starts above 20kmh and drops out below 20kmh, as in the sound.

mrobsessed wrote:That sounds like an air valve. Does it happen when you're stationary as well?

Solve your queries?

CQ Transport Man · Post by **CQ Transport Man** » Tue Jul 17, 2012 6:14 pm

Nope cuts out below 20kmh And When stationary no air is leaking. Though the Front & Back air guages do not alter. We have been told it maybe an Equalizer valve letting out under pressure when tilted or potholes etc it may hit. We have spoke to BCI In person at the depot and they may think it's equalizer, but then they responded and said from head office that 2 other coach buses in Australia have had the same problem unsolved. But hopefully it will be resolved.

Doc68 · Post by **Doc68** » Tue Jul 17, 2012 7:45 pm

Enjoy it

that is a modern vehicle with an excrement load of old school "character" rarely seen in todays vehicles. When other drivers say what is that ?? oh just the turbo winding down I had a good run into town

When passengers ask its, When I took it to the mechanic he said we need an exorcist & the nearest one is 100km. away

I do think an old aec or leyland that was melted for scrap some time ago has been used to make some air valves & try as hard as you will to find it whilst anyone is underneath, on the ground or in a pit you won't hear a sound from it.

Also some noises can't be explained one evening on my way to Adelaide I pulled into my regular sleeping area behind a servo that closed for the night climbed into the truck's sleeper & was just about out when a noise like a cartoon duck honk came from under the truck at about 20 to 30 sec. intervals. after I could not stand it any longer I jumped back in the seat and drained every last breath of air from the tanks

climbed back into bed just about to doze off happy & satisfied "honk"

Maladjusted · Post by **Maladjusted** » Thu Jul 19, 2012 4:42 am

On the youtube vid is it the sound at 35 seconds or the full length?

Simple to fix, -----if this is when it plays up, don't drive over 20 kph. Have heard lots of noises from air systems over the years, where valves allow small bits of air to move between tanks at regular and irregular intervals. It could be a regulator or relief valve, attached to an air tank and it only needs to move a small amount of air, so it vibrates on the seat of the valve. The experts at BCI Australia are looking at it and have 2 others doing it too, maybe they need to get some backup from the factory.
I give up, is this the equivilent to radio stations "The secret sound"

mrobsessed · Post by **mrobsessed** » Thu Jul 19, 2012 12:19 pm

I hope you got my PM, CQ.

My apologies, Busman444.

stevegj52 · Post by **stevegj52** » Mon Jul 23, 2012 6:31 pm

Trevor 062 wrote:Probably just another Illegal immagrant under there who maybe gets sea sick..

It's made in China thats the problem,have heard of so many problems from other operators who have puschased chinese built buses not just BCI either. Rode on a BCI to Geelong and every time it hit a small dip in the road you would hear a loud bang you would think the front end was going fall out.

CQ Transport Man · Post by **CQ Transport Man** » Wed Aug 29, 2012 2:49 pm

So far not an ait valve. we are further investigating with bci who are fully aware of the problem.

Daz · Post by **Daz** » Wed Aug 29, 2012 7:16 pm

Disk or drum brakes?

CQ Transport Man · Post by **CQ Transport Man** » Wed Aug 29, 2012 9:50 pm

Disc. The Caliper & brakes have been checked many times for anything caught hanging & dragging & air lines to and from etc. BCI are aware of the update today & will hopefully assist with the matter. I will keep you updated at a later date, thanks for the replies.

BLBUS · Post by **BLBUS** » Thu Aug 30, 2012 4:25 pm

Probably a fuggin chinaman caught inside, banging his little friggin hammer, trying to get out.... Hrrrrr got the headcount wrong at the factory that day

Daz · Post by **Daz** » Thu Aug 30, 2012 6:05 pm

Is there a stone guard that could be rubbing on a rotor?

Jack up the front axle and carefully use a large hole saw on a drill to spin each wheel up.

Daz

Bedford-29 · Post by **Bedford-29** » Thu Aug 30, 2012 6:21 pm

And all above don`t work just take it out and shoot it.

BLBUS · Post by **BLBUS** » Thu Aug 30, 2012 7:44 pm

Funny noises from buses are part of the fun. We had a BCI years ago, and it was a problem in the air dump valve, sounded like it was under the front, but it was actually just in front of the drive axle. Ended up dropping its guts in the middle of the Ipswich MWAY in peak hour. When it was checked, it had like a self tapper holding the valve in place. Screwed a washer back on and got it off the road... After market drier put on and all good

Daz · Post by **Daz** » Thu Aug 30, 2012 9:06 pm

It is the only time I have heard the owner of a thing, whilst still owning it, actually call a quarter million dollar vehicle a shitbox and genuinely mean it. Man that thing was a bastard.

Daz

smitty · Post by **smitty** » Sat Sep 22, 2012 6:49 am

We had a problem in a Daewoo of air forcing it's way up through the front end via the front access panel (where the bull bar is), it sounded like bumble bees under the dash. The rubber around the panel was lose so we stuck tape on it which solved the problem. The sound your BCI is making, and your description, sounds similar but it's a little hard to tell without sitting in the drivers seat....

User7526 · Post by **User7526** » Mon Sep 24, 2012 9:59 pm

Ok here's some serious thought from a mechanic of over 26 years experience. That noise is quite simply coming from something that moves when the vehicle is obviously.

It's not suspension related because it wouldn't do it on smooth roads which I believe isn't the case, it's something to do with what has been suggested here already. I've heard lots of noises like that which are wheel related and at that the cause can be back pressure forming within the brake circuit whilst driving which will make the brakes "drag' (does the noise come and go with brake applications?). It could be an airflow issue around the body but from what I heard it seems highly unlikely even from panels that might be flapping/vibrating. There could be an excess air pressure issue with the safety valve blowing off once the engine gets revs. up a bit while moving (I had some early Westbus B10Ms do that to me), if it is the problem will eventually come to be noticed when the vehicle is just idling but this would also be accompanied by excess pressure readings on the guages but if the guages are faulty?????

At this point I would like to ask about what wheel/brake/bearing checks have been done, if you don't want to discuss the finer points in this thread please send me a private message. I have read the replies here and I'm interested about the bearing check more importantly, I'm fairly well satisfied from the previous text that you don't have a dust cover or the like rubbing away.

Peta

moreton · Post by **moreton** » Wed Sep 26, 2012 5:03 pm

Just a suggestion the 3 know vehicles making similar noises, were they built one after each other in line, maybe the guy putting the rivets in panel or sicaflex on panel didn't use enough and they all perform same noise? Moreton