EA81 exhaust buzz

Silverbullet · Post by **Silverbullet** » Sun Dec 04, 2011 7:40 pm

Recently the old EA81 has developed a weird "buzz" noise at certain rev ranges. It used to do it in a very limited rev range so it was short and barely noticeable. But yesterday when my clutch started slipping because of no free play the buzz came in at a wider rev range and alot louder. Adjusted the free play in but the buzz is now in 2 different rev ranges and bloody annoying!

The noise definitely comes from the rear of the car/tailpipe from what I can hear on the inside.

What could I be looking at then, loose connection? Loose mounting? Where the two pipes join midway doesn't have the correct gasket in it, after I bought that gasket 3 times and had to take the exhaust apart 3 times I just cut a piece of cork mat and put lots of RTV on it and it was fine...perhaps that is starting to leak?

revmax · Post by **revmax** » Sun Dec 04, 2011 8:25 pm

maybe a loose baffle in the exhaust.

YouTube · Post by **El_Freddo** » Sun Dec 04, 2011 8:52 pm

revmax wrote:maybe a loose baffle in the exhaust.

+1 And check for cracking on the rear muffler, I had this on Sunnie the Brumby, a new (second hand) muffler did the trick for us.

Cheers

Bennie

steptoe · Post by **steptoe** » Mon Dec 05, 2011 7:39 am

then there is the spare wheel mounting bracket that breaks away from the firewall squeak, buzz affecting clutching to - where the stay bracket mounts to firewall. Also for the loose baffle in the muffler diagnosis. I guess if you get it checked by a muffler joint hinting that you want/need a 2" inch exhaust from y pipe back - they may be able to help rule things out.

Silverbullet · Post by **Silverbullet** » Mon Dec 05, 2011 4:53 pm

Hmm ok so loose baffle sounds possible since the noise is at the rear, I'll start looking for another rear exhaust section. Will check for cracks also cheers Bennie.

Jonno yes a 2 inch Y pipe back setup is on the list along with everything else

When you say stay bracket do you mean that rod going from the firewall to flywheel housing? That might need adjusting like the clutch did, how do I know when it's right? should it be tight or loose?

Cheers

sven '2' · Post by **sven '2'** » Mon Dec 05, 2011 6:10 pm

Also check the tail shaft.

It has a cardboard baffle inside that when loose sounds like the muffler is on the way out.

Tricked by this when I had my MV back in the day.

steptoe · Post by **steptoe** » Mon Dec 05, 2011 8:01 pm

cardboard baffle eh? must be leading towards the carbon fibre jobbies

Yep, the engine stay rod bracket. Adjust as per manual instructions best advice I can give. Leave it out and you have trouble driving or it tries to select 4WD or something. The brackets can crack at the firewall on the MY/MV

Silverbullet · Post by **Silverbullet** » Mon Dec 05, 2011 8:11 pm

Tailshaft...cardboard baffle?

just so I know what you're on about that's the shaft from gearbox to rear diff right?

Had no idea that had anything in it let alone cardboard baffles.

This has me baffled...

sven '2' · Post by **sven '2'** » Mon Dec 05, 2011 9:56 pm

Silverbullet wrote:Tailshaft...cardboard baffle? just so I know what you're on about that's the shaft from gearbox to rear diff right? Had no idea that had anything in it let alone cardboard baffles.

This has me baffled...

I tells the truth.

You spin a hollow tube at speed and will generate a sound wave. Hence the cardboard baffle within.

I thought it complete BS, until I replaced mine.

steptoe · Post by **steptoe** » Tue Dec 06, 2011 8:16 am

Just trying to picture Sam , full of waffle cardboard

NachaLuva · Post by **NachaLuva** » Tue Dec 06, 2011 10:39 am

sven '2' wrote:I tells the truth.

You spin a hollow tube at speed and will generate a sound wave. Hence the cardboard baffle within.

I thought it complete BS, until I replaced mine.

A cardboard baffle inside a steel tailshaft lol. Everyday you learn something new!

Must be pretty special cardboard so it doesnt burn when the tailshaft gets welded, maybe heat resistant resin or something

Silverbullet · Post by **Silverbullet** » Tue Dec 13, 2011 5:12 pm

Didn't get to inspect the muffler this weekend...by the time I remembered it was too late

But now the buzz is there in most rev ranges, also just today it's started popping and crackling like crazy from the tailpipe when coasting in gear (ie down hills or engine braking) but I'm not sure if this is muffler related.

sven '2' · Post by **sven '2'** » Tue Dec 13, 2011 6:30 pm

Silverbullet wrote:Didn't get to inspect the muffler this weekend...by the time I remembered it was too late

But now the buzz is there in most rev ranges, also just today it's started popping and crackling like crazy from the tailpipe when coasting in gear (ie down hills or engine braking) but I'm not sure if this is muffler related.

Based on this, muffler

Silverbullet · Post by **Silverbullet** » Tue Dec 13, 2011 7:40 pm

So does the muffler prevent this snap crackle popping? I thought it was my coasting bypass valve giving up as well. Better start ringing around for a rear exhaust half I guess. Thanks sven!

sven '2' · Post by **sven '2'** » Tue Dec 13, 2011 7:51 pm

Could be.

All the subes I've have owned snap crackle and pop, esp with a failing exhaust (or modified exhaust).

Try Dave at Gepps X Exhaust (next to Steve at Rising Sun)

Brumby Kid · Post by **Brumby Kid** » Tue Dec 13, 2011 8:00 pm

Yeah Dave is good. If it is like a mini backfire, it is probebly just a hole in the exhaust. That was my problem. Hmmm, get dave to take a look.
A new exhaust would always solve it, A nice growling lukey perhaps, Hahahahaha.

Silverbullet · Post by **Silverbullet** » Tue Dec 13, 2011 8:47 pm

Brumby Kid wrote: A new exhaust would always solve it, A nice growling lukey perhaps, Hahahahaha.

Not on what I earn

YouTube · Post by **El_Freddo** » Tue Dec 13, 2011 9:47 pm

Yeah it'll be a hole somewhere, possibly a crack down a section of the pipe that's letting air in to the exhaust to burn any unburnt fuel that's headed down the exhaust...

If you need to replace the exhaust - go the two inch

Cheers

Bennie

Brumby Kid · Post by **Brumby Kid** » Wed Dec 14, 2011 7:40 am

Silverbullet wrote:Not on what I earn

Yeah, I understand, Dad and i are finding it hard to justify spending money at the moment. And Mum and Dad both have Dr in front of their names.

YouTube · Post by **El_Freddo** » Wed Dec 14, 2011 3:58 pm

Do what I did all through uni - buy something useful or something you really need and go without something else to make ends meet. Save the same way for big items. Worked a treat and I'm still having a relatively good time at the moment. A job would help out a lot more but then again, I wouldn't have any time to do anything... I need sponsorship

Cheers

Bennie