Motorway speeds

[JonB]

Hi all

I commented on this before but a new thread is the best thing, I think.

My Plus 2 makes an odd noise at motorway speeds. It could be the gearbox, only I tried it in 4th and same noise. It's a kind of roaring sound, and so I wondered if it was just the wind blowing past the air intakes for the ventilation system. It starts at 60 mph and gets prominent 10 mph later. Really cannot tie it down to any location (such as the gearbox or diff), it sounds like it's coming from the front of the car.

Normal? Anyone else have it?

Cheers
JonB

PS, I can't try it out now - front suspension in pieces! Soon, soon...

[prezoom]

Try putting it in neutral when traveling at the speeds you indicated, to see if the noise goes a way.

[john.p.clegg]

I'm happy to say I can cruise all day at 85 , window down , elbow out and still chat to the wife with very little wind noise/buffeting , so good is the drag coefficient.

John

[JonB]

Try putting it in neutral when traveling at the speeds you indicated, to see if the noise goes a way.

I tried that, it didn't go away.

[Spyder fan]

Shame on you

https://webcontact.sussex.police.uk/asdprs/

[billwill]

I dunno about you, but in the past I discovered that for my Elan the 70 mph speed is not the most 'comfortable'. It seems to be where the aerodynamic shape has lifted the front end and made the steering too light, but not the back end.

Whereas at 80-90 mph, the whole car has lifted and bullets in a very stable way through the air like an aeroplane.


PS: this was before the 70 mph limit was imposed on motorways, of course.

[denicholls2]

The neutral test appears to rule out the pinion gears as well because you're coasting rather than accelerating and one would expect a difference with worn gears. I'd say you're left with bearings (wheel or differential) and wind noise. My vote would be to find sources of wind noise, good candidates are the window seals. Bearings would change pitch over different speeds and tend more towards a growl than a roar.

Taping over the vents with masking tape would be a way to find a diffference. As noted, most Loti are rather aerodynamically slippery to begin with. Sunroof?

[saildrive2001]

I agree with you Bill, used to cruise at 90-95 mph & the car felt smoother & happier at that speed than running at 70mph.

[JonB]

Ok, I'll try that, good idea!

[JonB]

Um. Since finding a leak after washing the car, I begin to suspect the air box seal to the intake is compromised. Maybe this is the cause... has anyone got a picture of the heater box to bulkhead seal? Can't see it in the parts diagram.

[The Veg]

Not the best pic as the seal is still attached to the heater, but here ya go. It's just a foam ring, I think about a half inch thick and about an inch from inner diameter to outer. Mine was in good enough condition to wash and re-use. If yours is gone you could probably improvise with some foam weatherstrip.

[vincereynard]

Get it to the point of noise and drop the window.

[JonB]

Get it to the point of noise and drop the window.

Err.. why? I suppose if there is a change in pitch I can assume it's the airbox. Or maybe you're saying "drown it out"?

[vincereynard]

Err.. why?

To pinpoint the possiblity of it being some sort of wind generated noise. You may be able to hear the source. Let the source be with you.

Whereas at 80-90 mph, the whole car has lifted and bullets in a very stable way through the air like an aeroplane.

Has anyone experimented with a small bib spoiler and vents down the bonnet sides?

[john.p.clegg]

like this...

me , no difference

John