Cabin fumes with half hood

[Gareth H]

Chaps, I've now had a couple of drives in the CSR with the half hood fitted, and the cabin smells of exhaust fumes, is this normal? The exhaust outlet is at 90 deg to the car, and I did wonder if it should point slightly downwards?

[Jonathan Kay]

Please could you add a side view showing the exhaust.

Thanks

Jonathan

[Gareth H]

[Jonathan Kay]

Thanks

Jonathan

(No problems with fumes in my 1800 K.)

[TJG]

Looks similar to my R400D which has no issues with fumes. Might be worth loosening the clamp and twisting it down slightly, just watch the load on the rear bobbin mounting.

Tony

[Billy.Whizz]

Of you have a heater try closing the vents, if that cures it then the fumes are coming from the engine bay.

 

[revilla]

My SV(same size as CSR) has a very "sideways" exhaust. I don't have a problem with fumes either.

[7 wonders of the world]

you get a lot of turbulance at the rear of a half hood and its possible to get rain drawn in a motorway speed with enough force to get to the windscreen so fumes will be easily drawn in.

[Geoff Brown]

Never experienced intake of fumes with half hood on in any circumstances.  And that is over a period of ten years.

As suggested angle exhaust tail down slightly otherwise you have an under bonnet issue.

[David aka Blue7]

From the photo it does look to be at the wrong angle and is normally pointing slightly downwards, maybe in the 8 o-clock rather than 9 o-clock position looking from the front.  Here is a photo of the CSR 485 from CC site.  The problem is that the silencer bracket would have to be bent to change the angle, if you just twisted the silencer and refitted it, it might place too much strain on the bobbin.

[Gareth H]

Thanks Chaps, I'll see it I can tweek the exhaust, it doesn't have a heater so probably unlikely to be engine bay related.

[David aka Blue7]

Gareth, one final comment, I have had 3 CSR's and this latest 2015 one has had problems with exhaust emissions seeping into the cockpit and nothing at all to do with the half hood.  I can't understand it but it isn't always there so I live with it whenever it occurs.  Probably not the answer you were looking for other than it happens.

[Graham Hutton]

Glad you raised this issue. I have only driven with my half hood on once and hated it. I definitely get the fumes smell and also a horrible droning resonance. Only to be used in emergencies I reckon.

[Benton]

Not scientific but..... on the basis I always find "road crud" on the back of my seats even when not using a half hood to me it seems the only explanation is there must always be some degree of air flow coming back into the cabin from the rear of the car.   Also as others have mentioned you can get enough "wraparound" air flow in the cabin  to coat the inside of the windscreen and mirror with crud as well.

The only time I've noticed exhaust fumes was when the lambda sensor went bad and you could detect the "rich" smell, and that was with a rear exit exhaust. I wouldn't be surprised if there wasn't some level of exhaust emissions always spilling back into the cabin given the Caterham "aerodynamics",  it's just one doesn't notice/detect it

#13  You definitely need earplugs/ear defenders with the half/full hood up as they accentuate the typical Caterham mechanical noises (though personally I use ear protection all the time)