manifold gasket clatter ?

[Chilliman]

Has anyone who has had a leaking exhaust manifold gasket experienced this as a slight 'clatter' on the 'over-run' (particularly the over-run from revving as the engine revs drop back to tickover whilst parked). Someone PLEASE say yes

[TVR Beaver]

Do you mean a slight 'ladl-ladl-ladl-ladl' around 1500 rpm and then as it reaches tickover it stops?
Sorry best description i could put to it

[haircutmike]

From memory when my gasket leaked, it made a constant ticking noise under load and dissapeared on the over run.

Use a short length of hose from your ear to various points on the manifold, it is instantly apparent if it is the exhaust!

Edited by haircutmike on Sunday 13th March 17:46

[Alexdaredevilz]

haircutmike said:

From memory when my gasket leaked, it made a constant ticking noise under load and dissapeared on the over run.

Use a short length of hose from yourear to various points on the manifold, it is instantly apparent if it is the exuast!

This ^^

[Chilliman]

Unfortunately this started the morning of the day I had to return to work so only got to stick my head under the bonnet for a few minutes before she was put to bed. It was then I was sure I could hear a blow from the manifold. It was only after I'd put her away It struck me that the clatter might be a manifold gasket doing impressions of a noisy valve train... I had a bad ticking from the top end of my B end of last year (also RV8) which I was convinced initially was mechanical, but was indeed a cracked manifold (new mild steel blockhguggers now fitted).

Ladle ladle may well describe it ... TVR Beaver have you had this and it turned out to be a manifold leak ? I'm not due back until the 18th (next Friday), was just hoping someone might say 'yeah I had that and it was a blowing manifold'...... ever hopefull.. thanks for the replies guys.

[TVR Beaver]

I agree with Peter.. the gasket is more reving up than over-run....
I have that funny noise sometimes I described... Think it's rockers or may be hydraulic adjusters (all of which are new so should be okay)... But they can get noisey when the oil get's hot?

May be... noises can travel and appear to be differant things on these things!!

[S3DaveP]

The top end on my Griff 500 rattles on overrun (1500rpm to tickover) when really hot, i think from what i heard that its fairly typical of a 500, although some say that using a thicker oil will stop it.
When i spoke to V8 developments, who built my engine they recomended valvoline 15-50 oil, i really don't know what's in mine as it was serviced by an independant before i bought it.

[Chilliman]

Hmm, I hadn't heard the noise before until the day I put her back in the garage . I guess it's possible it was alot hotter (inside the engine) than on previous days (did give her a bit of a ragging), although engine temp and oil pressure were as before... Be interesting to see if it still does it when I fire her up when I get home... booked into Kerridges on 21st so be interesting to see what the guys there make of it ! Have been advised to only use Mobil 1 engine oil (as per the handbook), interesting that V8D recommend valvoline.. mind you, the handbook is as old as the car... I guess oils have been further developed since 1998 The other odd thing it wasn't there one day and it was the next... you'd expect if it was wear related it would present slowly... sorry for rambling, just frustrated because I'm offshore, can't do anything about it out here, and it's bugging me to death....

[TVR Beaver]

Or may be with all the other noises they make, youd just not noticed it?... I tend to hear something and then hone in on it... Then thats all I can hear when I run it!!....
the top end thing does get exagurated by the garage also...
BTW.. i run Silkolene Pro R 15-50 (full symth).. and it still does it

[dog man]

It will be the lifters. You wont get that from manifold gaskets.

Mine did it once when super hot when revved quite high on the spot recently but has not done it since. (Mobil 1 motorsport 15/50) Mind you that was with the one way valve for the vac hose the wrong way round!

With lifter noise, if it doesn't do it all the time it's fine. (That's assuming all the rest of the valve train is correctly adjusted/set up of course)

A Lot of VW's rattle on cold start, some V8 BMW's too.

Naturally, if it does it literally on idle, not from overrun, then there is an issue and if it does it under load the cam and lifters have gone.

[TVR Beaver]

dog man said:

It will be the lifters. You wont get that from manifold gaskets.

Mind you that was with the one way valve for the vac hose the wrong way round!

OT... where is this.. I've seen it metioned a few times now... not sure I have one?? The hose comes out the rocker and goes to the plenum and base right?... Is it in here?.. I only have a T fitted??

[dog man]

No sorry it's not the crank case vent, I was talking about the hose for the vacuum advance unit on the distributor that goes from the plenum to the distributor. I think i'm being misleading though, the vac advance working or not will not have any effect on the lifters clattering.