Rattle from engine bay.

[nmh]

Evening all,

Has anyone who owns an S1 heard a metallic rattle coming from the engine bay during light acceleration?! It's most audible when setting off from standstill. I have had a good look at the engine bay etc to see if anything could be colliding at certain revs but can't see anything wrong.

[shangani]

Check the undertray bolts first - it is by far the most likely cause of the problem - the two allen key bolts towards the middle of the rear undertray.

[cej]

I have the same problem in my S1. I have taken the undertray and diffuser off,but still can't seem to locate where the sound is coming from. Still rattles

[Nick J]

Ive got the same vibration noise, driving me mad, will try the under tray and see if that is the cause, it does sound as though it is that but just havent got around to it yet.

[barrad]

Have you checked the metal plate that the ECM is mounted on? It has two tabs at the bottom which fit into two holes to hold the plate in place. Sometimes they pop out of the holes and the ECM plate is free to rattle. Had a rattle on my S1 111S which drove me nuts, tightened the undertrays, checked everything and had just about given up before I chanced upon this. However, the rattle came out going over bumps around town rather than on acceleration so may not solve your problem.

[ferrisbueller]

barrad said:

Have you checked the metal plate that the ECM is mounted on? It has two tabs at the bottom which fit into two holes to hold the plate in place. Sometimes they pop out of the holes and the ECM plate is free to rattle. Had a rattle on my S1 111S which drove me nuts, tightened the undertrays, checked everything and had just about given up before I chanced upon this. However, the rattle came out going over bumps around town rather than on acceleration so may not solve your problem.

I was going to say this. Mine rattles but I'm loathe to put some rubber around it becasue I know it will cause the ECM to heat up a touch.

[beachbum]

ferrisbueller said:

barrad said: Have you checked the metal plate that the ECM is mounted on? It has two tabs at the bottom which fit into two holes to hold the plate in place. Sometimes they pop out of the holes and the ECM plate is free to rattle. Had a rattle on my S1 111S which drove me nuts, tightened the undertrays, checked everything and had just about given up before I chanced upon this. However, the rattle came out going over bumps around town rather than on acceleration so may not solve your problem. I was going to say this. Mine rattles but I'm loathe to put some rubber around it becasue I know it will cause the ECM to heat up a touch.

Whenever I put rubber round something, its because I want it to get hot

[S Works]

Is it under accelleration and then goes after a while once the car has heated up?

[ChrisA]

The rattle quite often comes from the hand break cable rattling against the under-tray (not loose under-tray). This happens with time when the protective piece of foam rubs away. The rattle comes in and out when certain rev ranges are passed through.

I've solved this problem with a bit of rubber cable protector (The stuff they run across office floors to stop you tripping over wires.) Seems to do the trick. You'll need to take the diffuser under-tray section off and then the middle section, you'll see if it been rubbing by marks on the tray.

Hope this helps, Chris

[timoth]

hi guys not sure if this is the same thing but mine makes a sort of ticking noise seems to be behind the passenger seat about half way up it only seems to do it whilst coasting (foot only just on the acelerator)but not all the time and goes away after a while.

[tomtom]

Exactly the same with mine timoth.

S Works said:

Is it under accelleration and then goes after a while once the car has heated up?

I have this. I assumed it was a 'TADTS' thing.



>> Edited by tomtom on Tuesday 28th February 21:39

[S Works]

TADTS

[timoth]

sorry i am a newbie what is TADTS

[tomtom]

They all do that, sir.

[timoth]

cheers tomtom must rite that down

[tomtom]

You'll hear it a lot

[jcb156]

I had a rattle/vibration which turned out the be the heat shield underneath the "boot" which had dropped down and was rattling against the backbox. Needed a new one + retaining bits & bobs. You can see it with a torch just behind the rear wheel.

J

[beachbum]

Has anyone ever done a list of all of the initials people use so that a newbie would understand them.
Took a look on SELOC once and gave up trying to read onr thread, it was initials and nothing else, I didnt have a clue

[S Works]

Re: rattles etc. There are so many that 'could' be responsible it's almost impossible to tell on a website unless you can be really specific.

The one described I think relates to valve return springs - can't remember why they go quite, perhaps when it warms up they get lubricated better or something?

Best thing to do is join a local Lotus club and get friendly with your local specialist - generally someone will be able to listen/drive or be able to help find out the issue for nowt.

As for abbreviations etc. FFS use search

[zebedee]

antother one is a gratey rattly resonance - sounds a bit like a disintegrating catalytic converter - at low revs only - apparently caused by a loose exhaust bracket catching the undertray - mine does it, until I fix it at the next service that is...