Engine noise below plenum.

[Tegriffic]

In my Griff 4.3 something is making a very very disturbing noise, like something is broken. Spoke to Leven’s today about it (who were, yet again, helpful and accommodating beyond belief) and Dan advised that remove the plenum chamber to see if anything had come loose (the trumpets ???).

It sounds like a metallic knocking / clacking at the top of the engine block perhaps more to the offside if anything. It generally got worse over 30 miles or so but I'm sure the noise started originally towards the lower part of the engine (but I can't be sure of this).

Just wondering, when I remove the plenum is there anything I need to be careful of, like anything falling out (or is it just an empty chamber ?).

In fact, any comments welcomed.

Thanks.

[Ballistic Banana]

Its just an empty Chamber, quite easy to remove jsut remeber to when it is off to cover the Trumpet holes so as not to drop anything down there.
Undo Hoses and bolts, Shouldnt need to take Accelerator cable off, I took photos before with a digi camera just to make sure I put everything back as it was .
Unplug the Throttle pot from the Wire Connector block as so not to move the position as you may need to re adjust this?

Also befor hand when you have the main Hose off you can peek down the Throttle body with the butterfly open and prehaps see if any have fallen over.

Dont forget to seal it before replacing.

BB

[Guillotine]

cylinder liners or broken tappets would be my bet.

check inside the rockers when you have the plenum off

good luck

[tvr4ever]

Could just be 1 or more trumpets doing a dance. Have a look at this topic, it has a link to some photos of my trumpets 1 of them being loose and just lying there.
I to had a funny noise, that being the trumpet.

www.pistonheads.com/gassing/topic.asp?h=0&f=9&t=137782

Fred

[Guillotine]

good call

[starmist]

You'd be surprised just how much 'normal' noise there is there anyway. I've got an ACT carbon plenum, and you can really hear it. Don't be too worried!

[Tegriffic]

starmist said:

You'd be surprised just how much 'normal' noise there is there anyway. I've got an ACT carbon plenum, and you can really hear it. Don't be too worried!

This loud and new - it's definately not a correct noise. I thought is was the manifold venting but it is definately something broken, like a lifter or something.

[HarryW]

I think the advice about liftig the plenum top to check all the trumpet are still where they should be is sound advice. First place I'd look, only six bolts to peek at too .

Harry

[Tegriffic]

I appreciate all of this advice. What is concerning me greatly is that, once warmed up, the very loud noise appears to be in line with the engine turnover, it repeats exactly in time with the engine. It's exactly as you would expect with a manifold gasket ot something. it does not sound like something loose thats rattling about but more like something that hitting something else as the engine turns. i will remove the plenum at the weekend in any event.

[v8 racing]

could you give us some more imfo, cold hot underload etc.......

[Guillotine]

back to rockers or sleeve then

[Seasider]

Tegriffic said:

i will remove the plenum at the weekend in any event.

Hi Shawn, I should be about this weekend if you need a hand or second opinion...

[TeGriffic]

Del, Certainly wouldn't mind an opinion if you are about. At your convenience.

[seasider]

TeGriffic said:

Del, Certainly wouldn't mind an opinion if you are about. At your convenience.

Certainly can at the weekend... will give you a bell if i'm about & coherent during the week...

[Tegriffic]

If this is of use to anyone.

Finally pinned the suspect noise to a blowing manifold/gasket right at the rear of the engine. Although starting by sounding like a typical leaking exhaust it turned into a much heavier knocking / tapping which appeared to be coming from the engine itself. Armed with a broom handle, hose pipe, and a very helpful PH'r aka seasider, it seems that the sound is travelling in such a way as to sound as though it was a much more serious cause. Big hoorah's to seasider for his much appreciated help and expertise. Posted in case anyone else has similar symptoms.

[Seasider]

I by hope thats all it is after all that praise mate

Not expertise Shawn, just been there before...

Any time
Just call me Doctor Seasider

>> Edited by Seasider on Sunday 23 January 19:02

[david beer]

Dear Doctor Seasider, can you please come and do my top rear bush.I think the dogs Nylar Bone has bit the dust, its banging again !

[seasider]

Dear Mr Beer, can i suggest you stop being so cruel to your dog & return it's bone….

[red griff 500]

Tegriffic said:

If this is of use to anyone. Armed with a broom handle, hose pipe, and a very helpful PH'r aka seasider, it seems that the sound is travelling in such a way as to sound as though it was a much more serious cause.

Er, what did you do with the broom handle and hose? Serious answers only please.

[Tegriffic]

The sound travels up the broom handle and, with an ear pressed firmly against one end and the other on the engine, you can here the interiors moving. Actually quite effective. Same with the hose pipe on the manifold. Best to do it in a garage though, in private like.