[bmwak]

Hi Guys,

I have a 'sweetish smell' coming from my car's air vents once once it has been running for a while (I would say when running for atleast 45mins - 1 hour).

The engine bay also stinks of this and you can smell it from the front kidney grilles too (when you smell it from the front).

When you have been driving the car for a while it does give you a headache so I dropped it into the garage.

The smell is similar to unburnt oil and kind of Diesel too so the garage checked for diesel leaking around the injectors and also the fuel lines from the front all the way to the back to the tank but everything is fine and no leaks are evident (nor is anything getting low or leaking on my driveway).

I am now quite confused as to what it is but I assume it is NOT normal to get this smell (which is what BMW told me)

Has anyone experienced anything like what I describe? would appreciate if people could suggest would I should look at under the bay which could be causing this smell to come into the cabin.


Any suggestions appreciated.

[dxb335d]

firstly what is the car? I assume a diesel, does it have a diesel Particulate Filter?

If so it could be that going through a regenative cycle.

[quattrogmbh]

I often get the sweetish, toffee like smell when the car is going through the DPF regeneration (I have a 335d). It shouldnt be VERY noticeable though.

Nothing like the intense diesel exhaust gas smell I had coming through the vents when the turbo seals were failed though. Despite numerous attempts to repair at 3000 miles, BMW eventually replaced the vehicle.

[dxb335d]

Originally Posted by quattrogmbh

I often get the sweetish, toffee like smell when the car is going through the DPF regeneration (I have a 335d). It shouldnt be VERY noticeable though.

Nothing like the intense diesel exhaust gas smell I had coming through the vents when the turbo seals were failed though. Despite numerous attempts to repair at 3000 miles, BMW eventually replaced the vehicle.

FCUK ME,


Care to elaborate mate.

[quattrogmbh]

The original Thread : http://www.e90post.com/forums/showthread.php?t=111753

[bmwak]

Originally Posted by dxb335d

firstly what is the car? I assume a diesel, does it have a diesel Particulate Filter?

If so it could be that going through a regenative cycle.

Yeah its a Diesel 122bhp 2005 model so not got a Diesel Particulate Filter.

[beemerbird]

What about washer bottle and contents therein - sweet smelling? If a slight leak from a water based product, then the heat from the engine would cause evaporation not leaving any noticeable spilt residue where parked. Same principle for coolant fluid? Just a thought.

[bmwak]

Originally Posted by beemerbird

What about washer bottle and contents therein - sweet smelling? If a slight leak from a water based product, then the heat from the engine would cause evaporation not leaving any noticeable spilt residue where parked. Same principle for coolant fluid? Just a thought.

I've checked brake fluid, PAS Fluid, washer fluids and coolant all seems dry and nothing leaking from the pipes.

The smell is at its strongest in between a gap around the fuel pump but the pipes seem ok and nothing leaking from the injectors area so am stumped as to whether its a oil smell or diesel smell

[grey man]

'Sweet' smell sound most like antifreeze from the water. Ethylene Glycol (used for antifreeze) has a sweetish smell.

[greatbm]

Originally Posted by grey man

'Sweet' smell sound most like antifreeze from the water. Ethylene Glycol (used for antifreeze) has a sweetish smell.

Agree with the antifreeze theory, smell does get intense when coolant gets hot, may be slight leak on heater matrix in saloon so leak on drive not apparent and a slight leak will take a while to drop the coolant significantly. A pressure test may be needed to see if the system holds its pressure.

[bmwak]

I am convinced it is the smell of unburnt diesel but cannot seem to find the source of the leak. A local garage also said the same after having a smell.

I took the plastic top engine covers off and have had a look at the injectors and the fuel pump and nothing appears to be leaking (even with the engine on).

Nothing appears to be leaking in my car park space (but assume diesel would evaporate quickly) and the tank doesn't show the level getting low - however MPG is v low.

I think I will have to bite the bullet and give it into BMW (it is out of warranty) hoping its just a pipe or seal and NOT the fuel pump (but I guess I would be having more problems than just a wiff)

They said that it will be an hours labour at £168 for diagnosis. Just wondering would BMW usually remove stuff from the car (like unbolting components or fuel pump to source the leak) or will they only do a visual check? Its quite a steep labour charge and so am worried I will only pay for a visual checkover (bar removing the engine cover) which may not reveal anything tbh.

Cheers

[quattrogmbh]

I had an Audi once which had a hairline split in one of the flexible injector fuel return lines. Could only see it with the engine running when I flexed the pipe. It was just enough of a leak to create the odour but no visible residue was left.

[Greg 1]

i have got the same smell in my 320 d se e90 163bhp from what i gather i had the same smell in a older modle and it was put down to heated diesel smell escaping into the vents .Now i get the same smell in my 3 year old b m only in the cold weather and when the car is hot its just the smell of heated diesel + coolant so i guess change all filters and pipes or keep the heating off or just use a lot air fresheners

[bmwak]

Originally Posted by Greg 1

i have got the same smell in my 320 d se e90 163bhp from what i gather i had the same smell in a older modle and it was put down to heated diesel smell escaping into the vents .Now i get the same smell in my 3 year old b m only in the cold weather and when the car is hot its just the smell of heated diesel + coolant so i guess change all filters and pipes or keep the heating off or just use a lot air fresheners

Thanks mate, yeah I have already changed the panel filter (which I beleive is the only filter that filters what comes into the cabin vents. I have had this smell for some time but its quite strong and can make you feel lightheaded after a while on the motorway for example.

My independant garage couldn't find the cause and I am stumped myself.

BMW are going to do a further investigation tommorow which will be an hours labour - hopefully they can find something!

[bmwak]

Well BMW had a look and to me I don't think they can find the lexact area of leak to be honest so are saying to replace the common rail and the pipes at an extortionate cost of £700!

The thing is the smell doesn't seem to come from the injector/common rail area I don't think, its more near the fuel pressure pump but they are adamant its the rail and they are saying its just leaking down and causing the stink!They found some residue of diesel - although when I question them whether this was just an old leak or a fresh leak residue, they are only saying there is a leak residue - but can't put it to one of the four pipes or to which area.

The parts alone come to £405. I wonder if I can get it done under BMW goodwill as to me personally it seems a trial and error method - I wouldn't have thought the whole rail needs changing just the pipes?

[dxb335d]

she not under warranty?

[bmwak]

The warranty ran out March of this year.

It is under a non-BMW warranty but they declined the claim as it is considered as they consider the rail system as a pipe which is excluded from it.

[bmwak]

Well BMW replaced the whole rail and the metal fuel lines half price under goodwill but this smell still comes. It is however alot less and doesn't come from the vents as bad but is still evident from the engine bay!

BMW told me a certain amount of smell is normal.

Can anyone confirm if their pre 2007 diesel (whether 318d or 320d) has a whiff of diesel/coolant like smell when they open the bonnet after their cars been running a while. It seems to be coming from the engine bay when its hot (with the heated smell).

Appreciate if some people can check as above and post on here just so I can try and rule it out as I'm not sure if the dealer is just saying 'its normal'.

Many Thanks

[Dvazquez]

Hello
Im having this exact problem in my e90 318d 2008
Have you fixed your problem or do you still have a little smell?
I need to take my car to bmw...

[asus389]

I know this is an old thread, but did anyone find the solution to this? My e90 328i has the same problem. I slight sweet smell from the vents, but also near the front by the kidney grilles. Nobody can figure out why. Makes my dizzy and gives me headaches.