Exhaust vibration 2800 to 3200 rpm - exhaust tip sleeve?

[TFR]

I have a metallic vibration coming from the right hand side of the exhaust between 2800 and 3200 rpm.

I noticed that when you tap the exhaust tips they have a different sound, here's a video...

https://drive.google.com/file/d/1p_RMiWX01IOSaVEmQbkLt8sQSF4Sjeqz/view?usp=drivesdk

I suspect it may be the exhaust sleeve as there seems to be a few shims in there, doubled up etc, so expect it was bodged when the DesignTek exhaust was fitted in the past.

I have left some WD40 to penetrate for a day or so before fighting with the boot again so I can test drive without the tip.

In the meantime, what do you guys reckon?

Thanks as always!

 

[TFR]

Sorry, edited with an accessible link this time!

 

[DucatiRob]

It sounds like the welds that hold the sleeve to the pipe have cracked :?:

 

[YT61MH]

Isn't test driving without the tips a bad idea? Couldn't you melt your bumper?

 

[TFR]

Isn't test driving without the tips a bad idea? Couldn't you melt your bumper?

That is a valid point, thank you!

It won't take long to check the vibration has gone, I may only need to fire it up for 30 seconds.

 

[TFR]

Took it to an exhaust place yesterday and they are convinced the noise is coming from the water pump area, and not related to the exhaust tip or muffler.

Time to investigate further!

 

[b8575]

I haven't tried tapping the exhaust like you but I have the same issue on the right hand side between 2-2500rpm. Mine makes a kind of buzzing noise. It was diagnosed as a loose baffle inside the silencer but nothing to worry about too much. Going to get them changed when I get it serviced next

 

[TFR]

So my specialist has taken a look and they are convinced that the exhaust is fine.

The noise seems to be coming from the back of the engine, dead centre.

Here is a video, it's sound nasty when you are under there...

https://drive.google.com/file/d/1RBNTW1KJqbShVLBvsxnlOsviXApBtmD9/view?usp=drivesdk

It has had new water, oil and tandem pumps 3 years ago, along with a full rebuild and new ims while the engine was open.

They ran the engine without the belt and the noise is still present. They did mention that some of the pulleys are on there way out, but can wait until the belt gets done next year - not the cause of the noise.

Engine mounts? Crank pulley? Any ideas?

It is booked in again in 6 weeks time to start pulling bits apart and further investigation.

Do I need to worry?

 

[jpsh120]

I hope you are able to fix this issue without any significant expense.

Just FYI, when I had a similar problem with my 997, it turned out to be the small metal plates that are welded between the 2 exhaust pipes where they are close. Some of the welds had broken on one side causing the metal to vibrate (like a steel rule being twanged on the edge of a table!)

 

[TFR]

I hope you are able to fix this issue without any significant expense.

Just FYI, when I had a similar problem with my 997, it turned out to be the small metal plates that are welded between the 2 exhaust pipes where they are close. Some of the welds had broken on one side causing the metal to vibrate (like a steel rule being twanged on the edge of a table!)

Thanks, I am just gutted that I can't/shouldn't be driving it until it can be properly looked at in September - all the specialists are so busy at the moment!

Did the vibration/rattle sound like it came from the broken weld or did it transmit to somewhere else?

I have noticed that the oil pressure relief valve is weeping slightly so that could be causing it and I am also going to order new engine mounts, as this was a planned upgrade anyway as they have never been changed.

 

[jpsh120]

I hope you are able to fix this issue without any significant expense.

Just FYI, when I had a similar problem with my 997, it turned out to be the small metal plates that are welded between the 2 exhaust pipes where they are close. Some of the welds had broken on one side causing the metal to vibrate (like a steel rule being twanged on the edge of a table!)

Thanks, I am just gutted that I can't/shouldn't be driving it until it can be properly looked at in September - all the specialists are so busy at the moment!

Did the vibration/rattle sound like it came from the broken weld or did it transmit to somewhere else?

I have noticed that the oil pressure relief valve is weeping slightly so that could be causing it and I am also going to order new engine mounts, as this was a planned upgrade anyway as they have never been changed.

It was difficult to pinpoint where it was coming from. Hitting the exhaust tips caused it to make the noise but it was pure chance that I found the cause.

 

[TFR]

I've had it looked at again.

The stethoscope pointed them to the tandem pump, they replaced with one they had in the garage and the sound was still there.

They also tried to change the oil pressure relief valve, as there was a recall on the 987. This didn't get rid of the sound, but it did highlight a potential issue with the oil pump, as the outside of the valve seems to be scored, indicating that something is catching. The specialist thinks this isn't normal, what do you think?...

https://drive.google.com/file/d/1dgKb47mdT5HnLjl6lBZo2K_GQOx3KPxn/view?usp=drivesdk

I have read that the oil pumps are fairly reliable. How many hours are required to change one?

Running out of options now to avoid stripping the engine!