44 replies to this topic

[m1tch]

Will definitely check the bonnet stay tomorrow.
Yeah it's funny how everyone's mini seems to have some kind of rattle
I'm very aware that some people take advantage of owner of older cars claiming for more expensive problems etc that's why I'm keen to isolate the problem.

Yes it is underload when it happens, she runs very quietly with no odd noises when in idle and when you ease the accelerator. The rattling is a loose sounding rattling, sounding fairly tinny, its doesn't sound like a knocking sound more like something is moving around.

It could also possibly be the exhaust rattling on the bulkhead as im pretty sure your exhaust won't be standard, so check the clearance between the exhaust and the bulkhead.

Also check any engine steadies you might have top and bottom, preventing whatever it is rattling might help pin it down a bit

Was the engine tuned up before you bought it?

[Little Miss B]

Also just read up in the Haynes manual about the Tappets (cam followers right?), it mentions its highly unlikely to have any wear unless the engine has extremely high mileage, my engine has done 45,000 so not too high, do you think its still something to get checked out?

Thanks

[Little Miss B]

She has an LCB exhaust manifold and a playmini stainless steel side exhaust ... I’m beginning to think the best way to start is to tighten up a few bits and pieces that might be wearing loose ... she was tuned before we got her!

[m1tch]

Also just read up in the Haynes manual about the Tappets (cam followers right?), it mentions its highly unlikely to have any wear unless the engine has extremely high mileage, my engine has done 45,000 so not too high, do you think its still something to get checked out?

Thanks

The tappet gap can still change, the rockers won't wear out, its just that the tappet gap might change a bit, take the rocker cover off and give the rockers a wiggle on the screw end, if they click a bit and don't feel loose then they are probably about right, don't forget that some of them will be in compression, so you can't check those lol

[Little Miss B]

Great, thanks for that, I think checking this and checking for any other parts that might be rattling ... someone on another forum mentioned the exact same symptoms and the diagnosis was the tappets also!

[m1tch]

Always best to rule out all the little bits before you think its engine related, it might even be something as simple as someone has dropped a nut down next to the engine and its rattleing!

[Little Miss B]

So true! I have noticed the odd bolt missing

[shorty]

there is a rattling on mine at the moment which i thought was under the engine



then i realised it was the stone guard that i have somewhat broken...now the damn thing won't stop rattling grrrrr

[Ethel]

Never known a little end to fail, it's reciprocating and would likely cause all manner of problems leading to piston/ bore damage pretty quickly. Big end wear will drop the oil pressure (unless a blocked oil way is the cause) and is very predictable not intermittent. There's certainly lots of easier options to investigate first. If it is pinking, pulling the choke out a bit will enrich the mixture and should stop it. Changing gear is also useful, if it's coming from a rotating part of the engine it ought to speed up in a lower gear at the same road speed.

[Little Miss B]

Its funny how garages tell you right away that youll probably have to have the engine out ... will have to investigate this one too!!

[Little Miss B]

Just another thought, someone mentioned to me that it might be the timing gear chain, how likely is this. I'm going to have a look at her this morning and start eliminating some of of the problems.

[Ethel]

Timing chain is a possibility, there are lots of links in the chain so a fairly rapid engine speed related rattle would result. Irregular ignition timing may also be symptom.

You can also add a loose fuel pump to your checklist.

[Little Miss B]

** UPDATE **

We think we have narrowed down the problem area!

Definitely not these:
Bonnet catch/stay — nope, dampened this with rubber and it still happened
Checked for loose holding points etc. — nope, everything is bolted down securely
Underside exhaust movement (from behind manifold) — all seems tight and secure

So we drove her round the block a few times, to check where/when the sound was happening in relation to the revs, and it is definitely happening in relation to the revs, the higher the revs in any given gear (even 1st) the louder/more intense the sound gets, changing gear upwards elim inates the sound until the revs go a lot higher.
Curiously even in 1st/2nd with the revs held even you can occassionally hear it.

So, we poked our heads under the bonnet with the engine still going and upped the revs ... its without doubt coming from around the timing chain/fanbelt area.
(I think I can safely say its not the radiator fan as this is nearly new and is not metal!)

Has anyone had this problem then (seems as if a lot of peeps have!), looks like its an engine out job but probably not an engine strip and rebuild (yay)
Any thoughts!!

[Pauly]

I had a gear rattle which I found out after stripping the gearbox was caused by a worn layshaft, that only happened under load. But I cant remember it being tinny.

Does it only happen when in gear??

If not get a screwdriver and place it on parts of the engine where you think the noise is coming from, put your ear to the screwdriver and you will hear the componments and hear any rattling. Its like a cheap stephoscope .

If its timing chain then the pre tensioner could have failed, can be done with the engine in situ, bit fiddly.

Paul.

Edited by Pauly, 23 August 2009 - 10:00 AM.

[Little Miss B]

[quote name='Pauly' date='Aug 23 2009, 10:57 AM' post='1560794']
I had a gear rattle which I found out after stripping the gearbox was caused by a worn layshaft, that only happened under load. But I cant remember it being tinny.

Thanks Pauly ... it definitely sounds quite tinny, its definitely not deep/rumbly kind of sound ... does that help eliminate that?