Possible exhaust manifold leak

[daver clasper]

Hi.  Any trick or tips on diagnosing this please?, would be much appreciated.

It's a Vitesse Mk1 2 Litre

Thanks

Dave

[thescrapman]

They have a habit of cracking usually see a visible stain where the crack is.

[ferny]

Start it up from cold and use your hands to feel for the leak. You won't have long before gets to ouchy temperature though.

 

Does it need redex treatment? Put some in the bores, leave over night, put some more in and wait half hour, spin engine over (cover holes with rags!), put plugs in and start. You'll probably get loads of smoke and be able to spot a leak.

 

Wait for a realy cold morning, start it up and look for condensation coming from a gap.

 

Use your eyes and look for black soot at joins.

[RobPearce]

They also have a habit of failing the gasket, as the clamping isn't very good. Again, this tends to leave soot marks.

[daver clasper]

Thanks all, for your response, much appreciated.

Couldn't feel anything by hand and no visible soot marks (though could be underneath or at sides?, as very tight to see/feel anything there, as far as I can tell?.

Did use a narrow piece of hose to my ear and there was a ticking sound on no1, if the hose was held a few mm away from gasket at the top area. Couldn't hear it, if hose was moved to the head, close by. No sound like this from the other ports.

It was a tappety sound that I first heard, when driving over 1500 RPM and I checked tappets, a couple a bit gappy, so adjusted. No different.

I heard that leaky exhaust manifold can cause tappety sound.

Anyway I nipped up the fastenings a bit, for that port and it seemed quieter with hose, though maybe a bit of ticking still.  Driving I can't hear it.

So, do you think the hose diagnosed the issue please?. The exhaust gasket edges look very tired and are crumbly 

Also, any harm to engine, in running it if still has a small leak, (hot gasses burning the head/manifold gasket faces, etc) until I sort it?, as is my only car.

I'll maybe take a risk on CM poisoning as seems it would be very small amount and keep windows open.

Any more help, would be great.

Thanks, Dave     

 

[RobPearce]

It sounds like it's a pretty small leak, and the hose diagnosis is certainly believable. As long as it stays small then you're probably OK driving it like that.

[glang]

Id be surprised if theres not a soot mark somewhere Dave but as you say it could be hidden and need a boroscope camera thing to see it. Once the leak has started you cant reseal it and itll get worse as the gas flow burns away more gasket however that process can be pretty slow and I wouldnt worry about driving it like that.

It is a weakness in the MK1 but maintaining bolt torque I think is crucial as Ive had no more failures after starting a tightening routine on mine....

[daver clasper]

Thanks

I was thinking, maybe get a gasket from Canley or Chic Doig, as they do repairs, etc on Triumphs.

Have heard some can be dodgy, (maybe too thin?). Folk have suggested using two?.

Any experience of this please?.

Cheers, Dave 

[glang]

Not many NOS gaskets left now and theyre probably knackered anyway so probably only one Chinese company making them and supplying everyone! If two are needed then theres likely to be some misalignment or damage in the manifolds/head set up so worth checking with a straight edge and close inspection.

Also there always the possibility of making your own gasket as better spec materials are readily available and it wouldnt be too difficult to punch out the correct shape.... 

[daver clasper]

Cheers Glang. Will investigate the gasket material.

[daver clasper]

Hi. Looked at the generic gasket available. Seems good, though time consuming to cut to fit.

My exhaust manifold has max 20 thou difference on one inner port long the length of manifold (though this could be less, for example, to adjoning ports).

Do the seperate ports, close tighter/closer, in a bit , when torqued, I assume they would?  

Is this acceptable do you think for my "thinner than org, new, gasket".

Thanks, Dave

[glang]

I would have thought that a pretty normal difference as cast iron is known to 'move' over time and yes the clamps should pull it all into place. Of course too much and the manifolds are also renowned for developing cracks... 

However a thinner gasket would probably make it more difficult for any clearances like this to be taken up but correspondingly less likely to fail.

The later Spitfires use a modern multi layer perforated metal type gasket and although difficult to make one for the Vitesse I'd love to try it!

[daver clasper]

Cheers Glang. Here's hoping.