Technical Exhaust/diesel fumes in cabin

[SloMo]

Hi all, Candeese here, just joined and already a question...apologies I just purchased my first Fiat Panda 4x4 Diesel, 2014, and absolutely loving its versatility around town & the off road country track I live down, all good apart from one thing - the cabin on starting & running quickly smells of diesel or/and exhaust fumes so I've parked it up for the time being. I know a little and checked the manifold and cant see anything obvious or underneath following the exhaust and wondered if this was a common issue with a fix? The engine is clean and no oil or fuel leaks that I can see...I also did search on here but couldn't see an answer that fitted. Thank you kindly for any help.

 

[bugsymike]

Hi all, Candeese here, just joined and already a question...apologies I just purchased my first Fiat Panda 4x4 Diesel, 2014, and absolutely loving its versatility around town & the off road country track I live down, all good apart from one thing - the cabin on starting & running quickly smells of diesel or/and exhaust fumes so I've parked it up for the time being. I know a little and checked the manifold and cant see anything obvious or underneath following the exhaust and wondered if this was a common issue with a fix? The engine is clean and no oil or fuel leaks that I can see...I also did search on here but couldn't see an answer that fitted. Thank you kindly for any help.

Just a thought, with plastic engine cover off, any oil around the injectors or extra noise from there like not sealing in the head as common in the older ones, like a sort of spitting noise.
Other thing is leaking exhaust or oil getting on the exhaust

 

[RalphM]

Also worth checking the seal on the rear hatch as exhaust can get sucked back and into the car.

 

[SloMo]

Just a thought, with plastic engine cover off, any oil around the injectors or extra noise from there like not sealing in the head as common in the older ones, like a sort of spitting noise.
Other thing is leaking exhaust or oil getting on the exhaust

Thank you for helping. I removed the cover and it all looks clean and not suspiciously clean just untouched. I checked all the exhaust I can see from above and under the car but also nothing and the exhaust at he rear is clean & not smoking.....I'm determined not to spend money getting it diagnosed and would love to fix it myself...I'll carry on searching. Thank you.

 

[SloMo]

Also worth checking the seal on the rear hatch as exhaust can get sucked back and into the car.

Wow ...thank you, hadn't even thought about something like that...i'll be climbing into the back tomorrow for a sniff test!

 

[bugsymike]

Sometimes with the engine cover off and someone "blipping" the accelerator an exhaust or even the turbo can blow some exhaust smell or you may see the smoke.
Another check for exhaust leaks is one person holds a rag over the tail pipe firmly whilst the other listens for exhaust blows. Ideally the engine should stall if you have blocked the exhausts only exit

 

[Herts Hillhopper]

I’ll suggest two possibilities- and it’s likely to be both of them combined.
There’s a flexible coupling in the exhaust pipe more or less under where the centre of the dashboard is. This is prone to fraying and allowing some fumes to escape, but not necessarily sound as if it’s blowing.
And the rubber drain tubes that let the water run out from the space between the windscreen and the engine bay (called the scuttle) are prone to coming out of their mountings . These are designed to close up to stop fumes getting in the car, but if loose - as they tend to be as they seem to shrink with time - they no longer do that. The air that comes into the car (for the heating) is drawn from that scuttle area.
Search this forum for ‘scuttle drains’ or ‘duckbills’ to learn more about these. (On the current car they are quite large bits of runner, but on the pre-2012 Panda they were a smaller tube with a flattened end that looked like a duck’s beak - hence duckbills.)
If I can I’ll post a link to the relevant post in an edit here… [edit - see here and follow the links https://www.fiatforum.com/threads/scuttle-drains-no-duckbills.475219/post-4605595]
Also car exhaust won't kill you... not any more. Old petrol cars without a catalytic connector produced carbon monoxide (CO), which is poisonous. All cars with catalysts (and that incudes the diesels do too) will not have CO in the exhaust so while it may smell, it shouldn't kill you
[Further edit] - the flexible metal part of the exhaust tis in the centre of the first photo in this linked post... looks like 'knitted' stainless steel! https://www.fiatforum.com/threads/rusty-sump-guard.486312/post-4588465

 

[Herts Hillhopper]

Also worth checking the fuel filter isn't leaking. It's the metal can on the drivers side at the back of the bonnet, to the left (as seen from under the bonnet) of the dipstick. If it weeps, diesel will get absorbed into the soundproofing felt alongside it and (as above) can then lead to a smell coming through the heater vents via air drawn from the scuttle area.

 

[Goudrons]

It's often difficult to identify fumes from a diesel engine as different types of leaks can all smell fairly similar.
Exhaust gas often has some unburnt fuel in it, particularly at start up. So that can smell diesely just like a fuel leak, which obviously tends to smell of diesel as well.

When the engine runs it's normal for diesel to seep into the engine oil, so if there's a oil leak, that tends to smell a bit diesely also.

Generally a strong diesely/exhaust smell at cold start up in the car is likely to be from the exhaust.

Leaky fuel or oil tends to require hot surfaces and a little time to be drawn into the cabin to really stink up, so tend to start when the engine is warmed up a little.

HH's points you to the flexi pipe in the exhaust.
This is a good place to start as it's directly under your feet and is very prone to fraying and splitting so will allow exhaust gas out the moment the engine is fired up.

Fuel or oil leaks tend to be harder to spot. You really need to get under and look up as gravity tends to cause leaks to drip down.

Oil on diesel engines tend to get plumped into heat exchangers where engine coolant and the oil pass over each other.
These exchangers can be prone to leaking.
I think the exchanger on these is part of the oil filter housing, so is directly under the oil filter.

Leaks in the fuel system usually cause some running issues. The engine requires small amounts of fuel but under massive pressure so leaks tend to cause running issues, particularly when driven under high load.

You might also have a split hose somewhere. Like a split oil breather pipe, that will stink up as it's venting all the crankcase pressure out into the engine bay and as the oil can smell diesely, you get a similar smell.
It should be simple check to check the crankcase breather, perhaps HH can point you in the right direction as I'm no overly familar with this engine.
They usually come off the engine somewhere and plumb into the air intake, so the smelly gases should go into the engine and get burnt.

 

[varesecrazy]

Hi

If you bump a wheel up onto a high kerb you should be able to see around the exhaust flexi

Its a corrugated steel tube.. with a woven metal braid around it.. the Braid will be sooty if its leaking

 

[Herts Hillhopper]

… might also have a split hose somewhere. Like a split oil breather pipe, that will stink up as it's venting all the crankcase pressure out into the engine bay and as the oil can smell diesely, you get a similar smell.
It should be simple check to check the crankcase breather, perhaps HH can point you in the right direction as I'm no overly familar with this engine

Good shout… I’ll try and find (or take) a photo of this. There’s a rubber tube about 1cm in diameter from the back top left of the engine and into the bottom of the air filter housing. If that’s not connected (it gets disconnected if the whole air filter box is removed) it will blow dieselly smells out.

 

[Herts Hillhopper]

Hi

If you bump a wheel up onto a high kerb you should be able to see around the exhaust flexi

Its a corrugated steel tube.. with a woven metal braid around it.. the Braid will be sooty if its leaking

In the photo linked to you can see that’s just what I do — the left wheels are on the kerb and the front right on a bit of old sleeper the same height… easier than ramps

 

[Herts Hillhopper]

Just a thought, with plastic engine cover off, any oil around the injectors or extra noise from there like not sealing in the head as common in the older ones, like a sort of spitting noise.
Other thing is leaking exhaust or oil getting on the exhaust

There isn’t a removable plastic cover over the diesel engine - only a large air filter housing which is a bit of a faff to take off.

Also, since this is a 4x4 there is a substantial metal tray (sump guard) which makes it more tricky: anything that drips is hard to spot as the tray holds the drips and generally there’s a fine layer of mud/dust inside the tray that they soak into. That tray can be removed but it’s heavy and cumbersome - the car needs to be raised to reach the six or eight bolts, then a trolley jack is needed to support the tray as it’s guided out from under the car.

 

[Herts Hillhopper]

Good shout… I’ll try and find (or take) a photo of this. There’s a rubber tube about 1cm in diameter from the back top left of the engine and into the bottom of the air filter housing. If that’s not connected (it gets disconnected if the whole air filter box is removed) it will blow dieselly smells out.

Ignore this... the pipe I was remembering was on the petrol version. For the diesel, crankcase venting is more complicated, as it has to bypass the air flow sensor. It is in roughly the same place but harder to see

 

[bugsymike]

The one we had was a 06 Grande Punto 1.3 Multijet , so less pipe work to remove airbox.