I know they all do it, but......

[mad mark]

Why do all Cerbera's engines sound like a 'bag of bolts' when they are cold?
And what is that ticking from behind the dash when coming off gas? It sounds like (but I know it's not), a speedo cable ticking? I've had 2 Cerb's and they've both done it.
Niether a problem, just curious.

[nervous]

that would be the sound of 'character'. my car is positively filled with the stuff

[RR Cerbera]

Mark,

The ticking from behind the dashboard when coming off of the gas is due to a failed non-return valve (on the brake servo if I remember correctly). I'd guess its purpose it to prevent too much negative pressure from damaging a diaphragm somewhere???

I didn't notice any adverse effects before I had mine replaced although it did make me drive much more smoothly!

[vinny73]

Lol, I noticed that noise yesterday, sounded like keys tapping together when in the ignition and comes from that area'ish, but of course we dont have keys ;-)

[xsnowman]

Hi Mad mark

If you mean a metal tinging sound I think I traced it doen to the metal arm that links to the throttle cable. It has play in it to twist slightly and it is this twisting that when coming off the gas rattles. I thought it was coming from the air vent but went over the area the noise was coming from and found that this arm made the right noise!

good luck, p.s. mine also sounds like a tractor when it starts up but once it is warm is purrs perfectly.

[Byff]

mad mark said:

Why do all Cerbera's engines sound like a 'bag of bolts' when they are cold?

It's just the newness wearing off.

[Tyre Smoke]

Strange that, mine does the plink plink thing too. I thought it was because I had K + N's fitted (but not sure why that would make any difference).

The one thing that does annoy me though is the clickety clack from the rear brake pads.

Mine sounds like a bag of spanners falling off a cliff too when cold. The remedy (especially for a S6 so I hear) is to make sure you keep it at not less than 3k revs for the first ten minutes and only use first second and third gears. Apparently this stops ALL engine noise within a short period of time.

[tvr-fan]

[quote=Tyre Smoke]

The one thing that does annoy me though is the clickety clack from the rear brake pads.

quote]

In need of some heavy dudy adhesive then i think.....

Thats what they did to mine and appearently the way they are assembled as opposed to using springy things.

[TurboNelly]

tvr-fan said:

Tyre Smoke said: The one thing that does annoy me though is the clickety clack from the rear brake pads. In need of some heavy dudy adhesive then i think..... Thats what they did to mine and appearently the way they are assembled as opposed to using springy things.

Yep, mine too. Just bond the back of the pad to the piston - no more click-clacking

[kingstonking]

Ah ha! That ticking noise - annoyed me for 10 months. Sorted at Racing Green for very reasonable price indeed. They fitted another valve of some type (not a techie) and its gone for good (so far). Can recommend them.

Cheers

[mad mark]

So if this ticking is a brake related noise, then I guess I should look into it further.
I've not looked at a Cerbera's servo, but is the non return valve normally a small 'plastic' bit that connects the vac pipe to the servo?

[kingstonking]

Just to clarify - all garages etc that I spoke to described it as having no impact other than being annoying - not being an a techie I think it was something like excess "chatter" - they fitted an extra vale rather than change the existing one.

Hope this helps.

[mad mark]

Thanks, It's not really annoying, I was just curious.

Now what about the other part of my question,
What is it that causes all the engine noise when its cold?
Just curious again, I know it's normal on Cerb's.

[tvr-fan]

mad mark said:

Now what about the other part of my question, What is it that causes all the engine noise when its cold? Just curious again, I know it's normal on Cerb's.

I asked this question at my local tvr and they told me it was piston slap!!!
Still never mind they all do it so no probs eh.

[methodwares]

tvr-fan said:

I asked this question at my local tvr and they told me it was piston slap!!! Still never mind they all do it so no probs eh.

that's exactly what it is. if you take a look on phoenix's, or sxs or s-x-s or - or whatever his handle is this week's site, he's got piccies of the pistons. there is very little skirt on them. this allows the piston to twist (in the direction in normally does on the wrist pin) slightly more than a full skirt piston. all v-something engines will do this to some extent because the forces on the piston are not directly over the rod. once the piston warms up and expands, it is held a bit tighter in the cylinder.

the cams also produce noise cause of the valve lash when cold, and again, these tolerances are tighter once warmed up

[Steve_T]

My understanding was that the AJP8 was a loose engine, meaning the tolerences are only right when the engine is warm, which is why one needs to be very careful when warming the engine up.

Steve.

[mad mark]

Thanks guys.
I did think that it might have been piston slap but wasn't too sure.