Rattling sound

Technical Area Engine, Transmission, Exhaust etc
1
  1. My model of MX-5 is: NB 1.6 california
  2. I’m based near: Prestwick
  3. I’m looking for technical help or recommendations on: exhaust rattle.
    When I rev the engine on the drive I’m hearing a metallic rattle from the exhaust which appears to be coming from the cat area.
    Is this a common thing?
    Any suggestions?

Thanks…

2

Check heatshield, probably vibrating

2 Likes
3

My first guess would be a dilapidated heat shield but I shall be interested to hear what the experts suggest as my car has a similar malady.
I notice a metallic buzz as the revs move through about the 2K range.
Good luck in getting it sorted out.

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4

Thanks for the replies.
Is the heatshield on the cat?

5

Yes it is, the mounting points attach onto the actual cat itself, they corrode so you’re left with a loose heat shield that vibrates against the body of the cat. I’ve previously cut through with a pair of Gilbow shears (other brands are available) never had heat related issues once removed. :+1:

Barrie

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6

We get rattles on the Land Rovers that I work on from, as people have said above, heatshields (from the dpf). There is likely a place that will spot weld it for you if you don’t want to replace it or remove it

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7

You state the exhaust rattles ‘on the drive’, do you mean while parked on your drive or when you are driving it?

I’ve had an undriven (by myself) MX5 parked in one of my Son’s garage for 5 months while doing various jobs on it, don’t ask what jobs!
As it was nearing time to put it back on the road i pulled it out of the garage and noticed a tinny annoying rattle, also condensation drips from the mid pipe to backbox joint.
Off with the backbox fitted a new sealing gasket and checked the heat shield above the backbox, no problem until i started to put the car back in the garage, rattle, rattle, rattle!
A few days later (winter time) off with the backbox and realised the hanger rubbers had been incorrectly fitted, rechecked all the heat shields manifolds to backbox, again no problem found until i put the car back in the garage, rattle, rattle, rattle!!!
Now i’m getting a bit hissed off with it, (still winter time) a few days later and the snow has cleared, off with the backbox again, shake and hit the backbox,mid pipes, cats, manifolds and cross braces with soft mallet, still no fault found UNTIL i started to put the car back in the garage, rattle, rattle, rattle!
Really, really hissed now!
It was then that my youngest Son appeared and could see that i was a bit peeved, "what’s matter Dad? “can you hear that sodding rattle?” “yeah, try it now” no more rattling!!!
What he had done was put his hand on the up and over garage door which was resonating with the exhaust.
Which is why i asked was it on the drive parked or being driven.
Rattles can be very deceiving and could be from something on or near to your drive.

8

Hi
It rattles if I blip the throttle whilst the car is stationary.
It’s definitely coming from the cat/exhaust area of the car though…