Mazda MX5 Forum banner

mysterious knocking

13K views 28 replies 9 participants last post by  MX5_Owner  
#1 ·
Help. my mx5's developed a rather loud knocking noise emanating from the front. the best explanation i can think of is that it sounds like a bracket holding something on has come loose/off and something's swinging back and forward making the knocking noise. enlisted the help of steveti in searching for something loose but came up short (exhaust, suspension and all the underside feels solid). Has anyone else encountered a similar noise or know of a likely culprit for such a noise? Would take it to a garage, but due to the hours i'm working at the moment that's out of the window for the next couple of weeks.
 
Discussion starter · #4 ·
No, no spanners in the bonnet:eek: the knocking seems to be more prominent when i'm holding a steady speed on a rough bit of road although i still hear it intermittently on a nice smooth bit of road, hear it both whilst with full lock and straight. oh, and nothing in the boot either :D
 
Discussion starter · #10 ·
Front drop links or ARB bushes
gave the drop links a good yank whilst investigating the other day but will nip up to the car park at work tomorrow and try giving them a tightening. know what size spanner off the top of your head? if not i'll just take the whole spanner roll up with me
 
Discussion starter · #13 ·
damn it. on the plus side i hope it is the drop links as that'll be a cheaper fix than most. Can even fit them whilst fitting my new back box :D
 
  • Like
Reactions: MJL
Discussion starter · #14 ·
For the top ball joint (that connects to the ARB) you will need a 15mm spanner and a 4mm allen key
For the lower ball joint you will need a 14mm spanner and a 3mm allen key.
All of which i have at work. Nice!
 
  • Like
Reactions: MJL
Discussion starter · #22 ·
Chels,
When you fitted the Eibachs, did you tighten the front suspension up while the car was jacked, or was it all tightened with the suspension compressed eg on a ramp but resting on the wheels? If you did the former, it's a no no as it twists the bushes, and can lead to clonks. Check for them too.
Common error made in dealers...or was.
my pal who fitted them is aware of this particular faux pas.

I haven't been able to get a good look at the drop links but with full lock i could get a grip on it. how much movement should there be on the ball joints? When i grip the rod i can turn it through about 10 degrees.
 
Discussion starter · #25 ·
Well, fitted new stainless exhaust today, then got stuck in about the drop links. the top nut on both drop links were solid (had to grind them off), new ones fitted. went for a drive, no knocking noise:thumbsup::thumbsup: cheers for all the help, especially Hamish for the diagnosis and steveti for the hand and use of the facilities and extensive arrayof tools. If apple has an app for that, steve has a tool for that. Exhaust sounds tasty too