Technical fumes in the cabin

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Technical fumes in the cabin

gordinir8

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So my little beast has lot of emissions from the exhaust, good news is that at MOT they checking emissions at idle speed only so Eddie made it.(y)
Thing is that i also have lot of fumes inside the cabin and in order to kill the problem i removed the flex heater duct and block the inlet to the cabin with speed tape.:D Problem partially solved but i have still lot of fumes inside and i can't figure out how is this possible, there must be a passage somewhere, any thoughts or previous experience on this?

Thomas
 
I guess everything is there regarding the panels, there are no holes on the firewall and even if there was a loose connection on the exhaust from where it gets in? But ill take a look now that you mention it.
 
I had this in the past it turned out to be a leaking head gasket, there are hollow bolts in the cylinder head which are close to the exhaust bends. These let out exhaust gas from the cylinders, from the round groove in the cylinder head. So it might be a blown head gasket. When mine went it didn't loose a great deal of power.

Ralph
 
I have checked those and there is no leak from there. When you had the leak how fumes entered your cabin? Is there a passage or something?
 
I don't actually know how it got in but it did,once the head gasket was replaced the fumes stopped. It could get in by the getting into the cooling system and blown through, are you sure it's not oil fumes as this is a common problem with oil leaking from the push rod tube seals.

Ralph
 
Ralph I certainly have Oil leaks almost from all engine seals. I am sure that problem will go when I overhaul the engine buy I was hoping to solve it until then.
 
Thomas, if you have a lot of oil smell and drips in the engine bay, some of the vapour might be getting into the centre tunnel because there are a lot of holes at the back where all the pipes and cable come out. The grommets might be loose or missing or decayed.
If yours was an unrestored rusty UK car it is also possible that fumes might sneak under the back of the sills if corrosion was bad enough....but lucky for you I guess that it's not.
 
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I will remove all the back seat and under seat insulation and check for cracks and passages. Some seals from the tunnel are missing but i don't think that the problem. A thermal camera would be ideal for troubleshooting but unfortunately i don't have one.

Thomas
 
I removed back seats and insulation behind them. I found some of the factory sealant that seals the panels missing so cabin was not sealed from engine bay. Removed the old sealant from all panel joints and I will apply new seal everywhere. I found also some surface rust so I have to treat this as well and paint it. Maybe that was the problem but I have to test it to be sure.
Thomas
 
So after i installed new seal at the joints, (i am using aviation fuel tank sealant since it is the best seal you can use in my opinion and because i can find it easy). Anyway i have drive the car for a while and besides the fresh paint that stills smell no fumes observed so i guess problem is solved:slayer:
 
... i have drive the car for a while and besides the fresh paint that stills smell no fumes observed so i guess problem is solved:slayer:
Ignore all the above, smell is still here and comes from the outside. I also noticed today when i removed the inlet metal hose from the air filter to the carburetor that there is quiet a lot of fresh oil into the duct probably coming from the rocker valve cover fume hose. So do you think that my engine breathe air contaminated with oil and maybe that is a reason of fume smell?:confused::idea: Are your air filter to carburetor also oily inside?
 
There should be a spiral shaped brass mesh part inside the breather hose that goes from the valve cover to the air cleaner. It is supposed to stop most of the oil from getting sucked into the air cleaner.
A lot of oil in the air cleaner and intake pipe is an indication that the rings on the piston and maybe cylinders are worn.
John
 
If the rings or cylinders are worn then this can cause additional pressure in the crankcase which in turn forces oil through the valve cover vent to the air intake resulting in oil in the fuel mixture.

Ralph
 
This could also explain the high compression i measured of 135-140 psi?
On the other hand my spark plugs as i have posted here: https://www.fiatforum.com/500-classic/450476-spark-plug-colour.html?p=4266606 are free of oil and not wet with oil.:confused:
Also when i measured the emissions they guy at the shop told me that emissions comes from fuel and not from oil.
I am also missing that spiral mess which i doubt if it can hold oil, besides it is described as flame trap.
Thomas
 
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