Strange Motor Noise

[fdk]

Hi,

I've bought very recently a Lotus Elan Plus 2 130/5.

I think that the motor produces a strange inhalation noise. You can hear it here : http://www.youtube.com/watch?v=LvOuzZXMonw

What do you think it could be?

(I have not synchronise the carburators yet)

Thank you, and forgive me for my english, I'm French (nobody's perfect).

Fran?ois

[Frank Howard]

Francois,

Nice looking +2. It's difficult to tell by the video (audio?), but it could be a vacuum leak. First, I would get a fire extinguisher and have it handy. Then, I would spray starting fluid around the intake manifold but I would be careful as the starting fluid obviously is flammable and explosive. If the idle speed changes when you spray the fluid on a certain part, you've found your leak. Best of luck.

[Baggy2]

As Frank said it sounds like something sucking where it should not. I dont know if you are aware but the carburettors are flexibly mounted with rubber 'O' rings between the carbs and the manifold. If one of those was out of place you may get the sound recorded. For diagnosis I would use a piece of tube as a stethascope and move it around the engine until you find the exact location of the noise.
Its a great looking car - what colour is it and what type of wheels are they?
Baggy

[hartley hare]

hi there,have watched video,
has this just developed,or was it doing it when you bought car?
sounds consistent with engine tickover...hope it isnt, but could be a inlet valve seating problem..
suggest doing a compression test/valve clearance check...

good luck...

[fdk]

Thank you everybody for your help.

The engine was doing this noise when I bought it.
I will check what you explained when my mechanic will come back from holiday, in one week or so.


@Baggy : the color is regency red, and the wheels are the original one, but they are painted in aluminium color, without the black color at the center as they should do.

[terryp]

Fran?ois
Welcome to Lotuselan.net!

Bon Courage!!!!
Terry

[fdk]

Thank you Terry

Fran?ois

[peterako]

Hi Fran?ois,

Lovely looking +2!

Another thought.

That sound is like the sound I can get when the choke (cold start circuit) is open on my Dell'Orto carbs.

I see you have Webbers but have you checked that the choke is closed?

Best of luck,
Peter

Terry....looks like the plan to have all the +2's relocate to France is working

[elansprint]

Francois check it is not leaking around the headlamp vaccuum take off on no.1 cylinder inlet manifold. Good luck hope it is not something expensive & enjoy your new toy
Ian

[terryp]

Terry....looks like the plan to have all the +2's relocate to France is working

Peter
Its all in my plan for world +2 domination ......my plan is to have every +2 in France before 2020!!!!

Hope all is well

Terry

[fdk]

@ peterako : i've just verified. When I pull on the choke cable I can distinctively hear the aspiration noice of the carbs.

But the noise seems to come from the cylinder head, in front (radiator side). But my competence in mechanics are not enough for me to check more over. I will wait for the return of my mechanic next week.

I hope there is nothing to bad...

I will check the carbs (and the choke), the valves, and so on.

I'll keep you informed!

[fdk]

Here is a new video I recorded, making variation in running speed of the engine.

http://www.youtube.com/watch?v=N48YX_2_c9Q

[terryp]

Fran?ois
I think the valve clearances are the thing to check
Good Luck / Bon Courage
A+
Terry

[ecamiel]

sounds like a loose spark plug? missing spark plug ring?

Eric
64 S1

[JJDraper]

Synchronise the carbs. This sounds like seriously out of synch intake noise. The rest of the engine sounds mechanically good. 30 seconds with a screwdriver.

Jeremy