precats noise

[JKY]

1996 Griffith 500 - can the precats make a knocking noise? Mine has always had this noise and although sounds very mechanical, i have had comments before that it sounds like precats, and using big screwdriver to ear trick it definitely sounds as though coming from precats - noise is quieter on each individual manifold track but loud on the precat. Anything else that would resonate through to give this noise? It does get better as it gets hot.
All manifold gaskets done so pretty sure it is not that and precats looked good when manifolds were off but I guess you can only see the very end of them.

[Blown2CV]

they can disintegrate... could it be a manifold gasket?

[Hamburglar]

They certainly can desintergrate! The drivers side precat of my 98 Griff 500 was completely loose in the manifold, and was sliding forward onto the lamda probe under pressure. This being said it did not create any noise.

I have had manifold gaskets fail though, and they sound like knackered tappets on a fiesta (if you have that reference!)

Edited by Hamburglar on Thursday 17th September 17:09

[clive f]

I`d take the manifolds off, remove the precats and refit with new gaskets.

[TVR Beaver]

Just take the Y out and get your hand in.. see if they move.. if they do... pull them out... if not... remove rest of manifold and knock them out!!!.. stupid things!!

[Barreti]

Aaaaah yes, that Pre-Cat noise

The slow prowl rumble or the snarly fire spitting growl as these early TVR V8's with their sweet free revving engine blast along.

The early 'Pre-Cat' cars are smooth, revvy, fire breathing monsters which are beautifully loud in very best traditions of the British V8.

Being as they are unimpeded by the abhorence later inflicted on the car industry in general and the 5.0ltr version of these V8 cars in particular, in the form of the catalytic converters and precat exhaust syste.....

Ah...

precat...

errr, mmmm

Sorry to hear you haven't got a Pre-Cat

Edited by Barreti on Friday 18th September 08:46