Exhaust fumes in my 105!

[keithf]

Hi,

Just bought a 1968 1750 GTV and love it, very nice to drive! I do have a problem with fumes in the cabin and boot that I hope someone could advise me on.

I have had a new exhaust fitted, oil leak fixed that may have dripped onto exhaust, taped over exposed bung hole in spare wheel well, taped a plastic bag under the rear speaker housing and plugged any holes in the bulkhead. I thought the fumes maybe coming in through the boot rubber or the spare two numberplate holes but these look fine. I am not sure what the correct boot rubber should look like but assume mine is correct.

The fumes come in when I have the windows down and I can't tell if they are sucked through the rear of the car or somehow come in from the tailpipe itself. I will be checking out a few cars at AutoItalia incase I have a non standard rear pipe that is causing some sort of airflow issue.

On a long run even my clothing smells of exhaust, not good!

Any ideas out there?

Cheers
Keith

[Gary Pearce]

Hi Keith, sounds like you are on the trail. If it is exhaust (carbon-monoxide) and your exhaust system is sound all the way along (no leaks), then the suction is at the rear somewhere. All cars produce negative pressure at the rear as they move through the air. Don't forget if it is carbon-monoxide this is very dangerous and you should investigate closely particularly around the back. Tail lights, under the rear and in particular the boot lid seal. The correct boot lid seal should be glued to the boot lid and compress down on the raised water channel to produce a perfect seal.
If you are wrong and the smell is burning oil, then that's another story.
Usually the boot around the gear lever, the boot around the accelarator, various fire-wall holes, holes in the floor and even the heater unit cal all allow oil smell to permiate through.

[keithf]

Thanks Gary,

The seal I have got fits on the aperture which I think is correct for the model, but mine does not have the small upright extrusion that Alfaholics have today send me a picture of from the UK. I will try one of these and also put some sealant around the fuel tank incase it is leaking round there. If I have the wrong seal and manage to get one that glues to the lid what goes on the raised lip of the aperture itself? I think the early cars pre 65 had the bootlid mounted one but not an expert on these cars....yet!

Gearlever rubber boot looks good but vinyl needs replacing, the next job.

Cheers
Keith

[Colin Byrne]

Hi kieth
Are you sure it's exhaust and not just fuel? I've had plenty of dramas with the fuel pickup not sealing in the tank properly and filling the cabin with fumes, very uncomfortable especially on the eyes!  Sounds like you have done a good job of sealing up the cabin, the only other place exhaust fumes could come in that I can think of is the hand brake lever, there are some pretty big holes through that and no rubber boot just the vinyl cover.

[Gary Pearce]

Keith I'm pretty sure the model you have should only have a boot seal on the lid. Not on the aperture. Lots of mod sare likely to have been done however and your boot lid is sure to have had some work over the years.
The job at hand as I see it is to carefully diagnose what the smell is, Co2 or burning oil or petrol vapor as Colin is suggesting.
You might like to find a lepricorn, lock him/her in the boot and go for a drive. If he/she expires it's likely to be Co2.

[keithf]

Thanks gents for replies but I think I started with all three, oil, CO2 and fuel and think the last one left is the exhaust! Will check round the handbrake though, did not think of there. Lepricorns a bit thin on the ground...

[AndrewO]

Hi Keith,

I had a similar problem and have filled so many holes I have no idea which one fixed it. 
One thing you haven't mentioned is the engine ventilation hose that goes from the cam cover into the air intake.  Is yours standard or has someone taken it out of the intake and let it go to atmosphere (most likely if you have a modified air filter arrangement).  If it has been done make sure the air leaves at a very low level under the car not just in the engine bay or it will be sucked up into the cabin air intake.  Mine was (and is) also missing a rubber sealing strip across the engine bay near the windscreen and I imagine engine bay fumes get sucked under the bonnet to the ventialation air intake.

There are also I think 3 boots around the gear lever and one of mine was perished so air was being sucked up through there.

Keep plugging away.

[AndrewO]

Oh, I forgot.

Mine is a 1968 1750 GTV and my boot seal is attached (push fit only) to a raised lip on the body itself, not glued to the boot lid.  I'm not sure of any differences or what should be there.

My fuel smell was (and is but soon won't be) coming from the o-rings on the covers for the 4 pump jets on the Webers.  Normal harware store o-rings aren't fat enough to seal it.  They had virtually rotted away and when you pushed the accelerator you could see the fuel seeping out of the rings and going down over the carbs.  An eye watering experience but luckily nothing worse.

[keithf]

Thanks Andrew, plenty to get on with! Will check the gearlever boot and yes my rear engine bay edge does not have a seal so could be coming in through there. I'm sure the bootlid seal is correct and push on as yours is. I did mention the O rings to Luca in Leichardt and he seemed to think mine were ok. Standard air filter box with a large airpipe going to it but I will have a proper look tomorrow.

Cheers
Keith