Noise from underside middle section of car

Technical Area Engine, Transmission, Exhaust etc
1
  1. My model of MX-5 is: Sport Graphite 3.75
  2. I’m based near: Manchester
  3. I’m looking for technical help or recommendations on: A squeaky noise when car is idle.

Hello all,

I’ve noticed recently that the middle underside of my Mx5 is making this really irritating squeaky noise when it’s up to temperature and at idle. When I give it some revs the noise goes away, has anybody experienced similar or knows what this could be?

My first thought was the exhaust hangars squeaking but I’m really unsure. I got a custom mid pipe fitted around 8 months ago and haven’t had issues since until recently.

TIA

2

Prop shaft?

3

At idle? I read that as stationary.

Could be a dry exhaust rubber perhaps, moving slightly on its mount from engine vibration. Does the noise change if you press the clutch?

4

Ah, yeah, good point… Squeak from the underside that goes away with revs, brain went immediately to propshaft!

Obviously the solution here is to get under the car and have a listen close up. Pop the exhaust rubbers off one at a time to eliminate those.

Some decription would help. Is it a constant, metallic squeak? A staccato? Does the squeak come back when the revs drop again?

5

Well I had a look underneath and it seems like there’s a small hole in the resonator on my exhaust due to the car being lowered. Could be worse but still a very annoying hissing noise.

6

In which case (if you don’t already have some) a dab of GunGum is the quick and easy answer.

7

I will definitely try that out, cheers mate :+1::+1:

8

Just the paste won’t be enough, you’ll need either one of the metal strap type bandages or the fibre bandages to hold the paste in place. I tend to use the metal ones because they look better.

Yet another casualty of a lowered car… I don’t understand why people do it…

9

GunGum is fine for a small hole (follow the instructions!), but I agree if it’s anything more than a couple of millimetres, or a split, then a bandage will be needed.

My first three decades of impoverished banger motoring depended on judicious application of GunGum etc. In most cases of a pin-hole or two it usually lasted until the exhaust fell off, maybe a year or two later!

The dabs I filled the three rust holes with in the Niseko’s rear pipe bend (near it’s joint-flange to the backbox) lasted seven years, could have done more if the car wasn’t written off by the insurance company

10

Yeah I think it’s only a small hole tbf so I’ll give that a try, I only got it done maybe 8 months ago but it scrapes a lot :confused: . Thanks for the help mate

11

Yeah I’ll see how it is. And ask the previous owner :joy:.

12

I must admit I’ve never put the stuff on and then waited for it to set, so I’ve always been forced to bandage it up as well! I’ve had a couple of exhaust made out of paste and coke cans more than stock :smiley:

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