Annoying buzz from oil filler

[GT42023]

I have an annoying buzz from the oil filler.
It happens from 6 to 8 thousand revs.

I initially thought it was from the outer cap so removed it, test drove it & it was much louder.

Has anybody had this & do they know of a fix?

 

[Motorhead]

That’s a new one on me but it sounds as though there’s a loose connection somewhere on the pipe connecting the cup containing the oil and coolant filler caps to the engine and the only way to check this out is to remove the top engine cover and have a poke around.

It goes without saying that there’s a lot of sound and vibration generated at higher engine revs and the pipe’s acting as a conduit into the cabin, especially since you’ve removed the filler cap!

Jeff

 

[GT42023]

Thanks Jeff,
I found this online so once the trim is off the oil filler area, hopefully I should have good access to the filler & section of pipe.
Probably just needs something tightening up or a bit of foam. It's driving me crazy so I am on a mission to sort it.

 

[Motorhead]

Yes, I would start by making sure that the Torx bolt(s) securing the black plastic cup holder to the body are tight and then that the blue cup itself is a tight fit in the holder. I can’t see the flexible pipe from the filler to the bulkhead being the issue. Beyond that it looks as though access to the lower section of the pipe to the engine could be a bit tricky, but maybe removing the access panel behind the seats will help.

Good luck, and keep us posted on progress.

Jeff

 

[Scrounger]

Its the caps that buzz. Some have found adding a small amount of felt helps.

Dan

 

[GT42023]

Was hoping that would be the case but with the outer caps removed, the buzzing is much louder in that area, I removed the trim & upright section of carpet & found nothing that could be the cause in my case. Now I'm wondering if its something possibly in the intake on the drivers side which only rears its head in the higher rev range.

 

[Motorhead]

I think that your best bet is to get someone in the car with you to see if they can find the source of the sound while you drive. A bit tricky in the confined space of the Cayman’s cabin though!

Jeff

 

[Stirls]

Was hoping that would be the case but with the outer caps removed, the buzzing is much louder in that area, I removed the trim & upright section of carpet & found nothing that could be the cause in my case. Now I'm wondering if it’s something possibly in the intake on the drivers side which only rears its head in the higher rev range.

I had this for a short while (straw in fan noise) and knew something had been ingested drivers side but fortunately it self cleared later in journey. Didn’t fancy pulling panel off to looksee at time but is only way to be sure if persists.

 

[Motorhead]

That had crossed my mind too, but if it’s engine speed related that would imply a resonance above 100Hz. Worth checking-out though.

Jeff

 

[GT42023]

I'll report back when I get to the bottom of it.

 

[GT42023]

Finally found the source & fixed it.

It was the oil filler & the inner filler cap O ring was undersized.

I removed the rear trim & upright carpet then removed the ecu, 2 upper bolts then 2 nuts below.

I then removed the pipe from the bottom of the oil filler then the oil filler itself, 2 x torx bolts & a slide in plastic fitting.

The design is not very good as it allows for movement between the yellow plastic part & the outer black frame. I split it using a trim tool, added foam pads as below then re-assembled.


I then test drove it & it was much improved but still a slight buzz at high revs.

I then removed the inner oil cap & it has 2 'O' rings one small then a larger 80mm O ring. I noticed there was slogger between the inner oil cap & the yellow part so I removed the 80mm O ring, replaced it with a thicker one & now the irritating buzz at high revs has completely gone.



I can now enjoy the car again as it has been bugging me for months.

 

[JohnCRS]

Thanks for the report back! Always good to hear what works!