Hi people.

First time I have noticed this since buying my car on 22nd December.

I was driving along and noticed the faint smell of diesel in the cabin. There were no other issues that I noticed. Car still drove normally etc.

Could this just be the car doing a DPF regeneration? I read somewhere a forced regeneration is done by the car by injecting diesel later to force exhaust temperature up.

Can anyone advise, is this normal or should I go to the dealer (car has a 12 month warranty)

A forced regen can only be performed when the car is plugged into a diagnostics machine.

 

A passive regen has no affect as it is performed during normal driving conditions.

 

An active regen is when the RPM increases to 1,000rpm, this is the most obvious sign a regen is underway. You may also notice the engine fans running after the engine is turned off (if you interrupt the regen) and a faint smell of burning from the hot exhaust.

 

Either way there should be no smell of diesel.

 

If you can small diesel then you have a leak somewhere.

Lift the bonnet and see if there's any soot on the inside of the bonnet or anywhere around the turbo and DPF - which is to the left of the turbo as you look in the engine bay. 

 

There shouldn't be any diesel fumes leaking from the exhaust system at all. I am guessing you are referring to diesel FUMES rather than unburnt diesel? If the latter, pop the plastic engine cover off and see if there are any signs of a fuel leak anywhere. It should be fairly clean and dry under the engine cover. And just have a general nose round with a torch for signs of diesel anywhere. 

 

The obvious warnings for moving belts and fans, as well as 'kin hot bits of turbo and DPF components applies! 

See here, any smoke?

 

http://www.briskoda.net/forums/topic/384270-smoke-from-engine-bay/?hl=%2Bdiesel+%2Bsmell

I haven't noticed any smoke. A bit of white smoke out the back as I pulled up to and then away from a roundabout, put that down to cold temperature outside.

Continued driving and I can't smell the fumes anymore. Has only happened tonight.

It was similar odour to what you get when filling the tank.

This is the first diesel car I have owned, so not sure what's "normal" and what isn't.

Ideally, there should never be any kind of diesel smell, burnt or otherwise. The smell of a DPF regen is due to the heat generated during the cycle. 

 

The white smoke from the exhaust can be as a result of the soot being burnt off and slung out the exhaust during a regen cycle. If it wasn't condensation of course.....

 

It's still worth having a little look under the bonnet for signs of diesel leakage and/or black soot around the exhaust components. 

 

My first Superb (with a similar CFGB engine to your vRS) had to have the DPF replaced, as the fitting where it connects to the turbo was pi$$ed. Fumes were leaking from the clamp seal between the turbo outlet and the DPF inlet. Apart from the occasional smell of diesel fumes in traffic, I noticed a thin film of black soot on the inside of the bonnet, mostly above the turbo oddly enough. 

 

The main reason I urge you to check it out is the obvious effect diesel fumes can have on the occupant(s) when entering the cabin. Tiredness and fatigue being the worst. 

I have an idea. It might be silly but couldn't you be affected by other cars? If you drive usually in urban areas then it's highly possible that you feel the exhaust gas from another diesel.

Only time I've ever smelt diesel fuel was in my 406 HDi. Many years ago I went through a stage where I'd try to drive very economically on the motorway. At the end of a long run in warm weather I'd smell warm diesel. I think it was the fuel endlessly being circled between the fuel tank and the fuel pump(s) and getting heated in the process. 

 

I don't do that anymore  :no:

Ideally, there should never be any kind of diesel smell, burnt or otherwise. The smell of a DPF regen is due to the heat generated during the cycle.

The white smoke from the exhaust can be as a result of the soot being burnt off and slung out the exhaust during a regen cycle. If it wasn't condensation of course.....

It's still worth having a little look under the bonnet for signs of diesel leakage and/or black soot around the exhaust components.

My first Superb (with a similar CFGB engine to your vRS) had to have the DPF replaced, as the fitting where it connects to the turbo was pi$$ed. Fumes were leaking from the clamp seal between the turbo outlet and the DPF inlet. Apart from the occasional smell of diesel fumes in traffic, I noticed a thin film of black soot on the inside of the bonnet, mostly above the turbo oddly enough.

The main reason I urge you to check it out is the obvious effect diesel fumes can have on the occupant(s) when entering the cabin. Tiredness and fatigue being the worst.

I will certainly have a look under the bonnet for the signs you have mentioned.

It is possible it could of been the vehicle in front of me, but was strange that the smell occurred at the same time as white smoke out the exhaust. Don't think it was condensation as never noticed it before or after the event and the car was up to temperature.

If happens again will go back to the dealer. Should be covered by warranty if there is an issue.

I try to keep my revs low, is this a bad idea in a diesel?

I try to keep my revs low, is this a bad idea in a diesel?

 

What do you consider low revs? I try not live from 1500 to 2300 (don't like how car acts below 1500 rpm. ~2k rpm feels the best). Sure, overtakings and similar actions are exceptions.

Diesels produce lots of soot what settle on every possible surface - exhaust system, turbo, EGR, etc. Driving at higher revs may clean all that. It's also said that accelerating at low revs is bad for the expensive dual mass flywheel as well (some other member might comment on this).

I doubt that driving on low revs is any good for fuel saving as well. I've tried a few times driving below 1500 rpm and watching computer's fuel consumption values - actually they weren't any good (especially in 6th gear). Anyway, even it helps me saving some little amount of money, I won't ruin my driving joy.

Considering the car idles around 1k. I tend to keep them below 2.5k (I believe my turbo kicks in at this rpm) other than overtaking/accelerating up to speed. Then let it settle. 30mpg in 4th/5th gear as most of my driving just now is town with occasional motorway/dual carriageway. Will only use 6th at motorway speeds.

Maybe I am driving with too light a right foot?

I think diesels generally like to be worked hard. Warm it up first. 

 

Labouring the engine in a high gear places a heavy load on the engine bearings and isn't good long term. Its Ok if you're coasting.

 

This information may be out of date and I am no mechanic, mind. 

I will certainly have a look under the bonnet for the signs you have mentioned.

It is possible it could of been the vehicle in front of me, but was strange that the smell occurred at the same time as white smoke out the exhaust. Don't think it was condensation as never noticed it before or after the event and the car was up to temperature.

If happens again will go back to the dealer. Should be covered by warranty if there is an issue.

 

At this point, I would spend 5-10 minutes with a torch looking around under the bonnet and under the plastic engine cover for any signs of soot or diesel fuel. If you can't see anything obvious, it's likely there's no problem. Better safe than sorry with diesel fumes though. 

I think diesels generally like to be worked hard. Warm it up first. 

 

Labouring the engine in a high gear places a heavy load on the engine bearings and isn't good long term. Its Ok if you're coasting.

 

This information may be out of date and I am no mechanic, mind. 

 

It's not good for the DMF either as low revs and high load is where it works the hardest and is under the most stress. I always give mine an Italian tune up on a regular basis - once it's fully up to temperature of course. It's not a hire car! 

Give it some beans! 

It's not good for the DMF either as low revs and high load is where it works the hardest and is under the most stress

What do you mean by low revs and high load?

I don't feel like the engine is labouring, if I notice that I change back down a gear. The car seems to be happy at 30mph in 4th/5th gear depending on road. Definitely feels laboured in 6th. I now realise 6th gear is for cruising at motorway speeds not town driving as it lowers the revs too much.

At this point, I would spend 5-10 minutes with a torch looking around under the bonnet and under the plastic engine cover for any signs of soot or diesel fuel. If you can't see anything obvious, it's likely there's no problem. Better safe than sorry with diesel fumes though.

Where's the most likely place to search other than under the engine cover?

If I look into the engine bay from the front what side is the turbo/DMF located? Drivers side (my left) or passengers side?

Thanks for all your tips

Have a look at my thread here, had same issue turned out to be DPF gasket and clamp

A video is posted

http://www.briskoda.net/forums/topic/384270-smoke-from-engine-bay/

Where's the most likely place to search other than under the engine cover?

If I look into the engine bay from the front what side is the turbo/DMF located? Drivers side (my left) or passengers side?

Thanks for all your tips

The suggested video is a good source of info. 

 

The turbo and DPF are right at the back of the engine bay, check them for soot. Look under the engine cover and around the fuel filter for signs of diesel fuel. If you don't find anything obvious, I'd forget about it for the time being - unless you pick up on any more diesel smells. 

Thanks for all your tips and advice.

I will have a good look under the bonnet tomorrow (if storm Gertrude has buggered off by then)

She has ripped my cast iron drain pipe off the wall of my house.

Definitely don't want to chance the cars bonnet.

Are you smelling exhaust fumes or fuel fumes, if it's fuel check underneath the tandem fuel pump for leaks.

I believe it was fuel I could smell. Haven't noticed it again since. Had a quick look under the bonnet by the fuel filter and the turbo but can't see anything that looks sooty.

I will keep an eye on things and if it comes back will go to the dealer.

How does the engine cover come off? I couldn't see any obvious bolts to undo.

grab the top corners and pull, then do same on bottom, 

 

Just pulls out

I noticed another issue last night. May or may not be related to my initial query.

After driving the car a short distance (engine was still hot from previous journey) I stopped to speak to someone got out and walked round the front of the car while engine was running and noticed a smell of diesel from the passenger side. Was definitely exhaust rather than raw diesel. (was a little windy so possible the wind blowing the exhaust)

I finished conversation and continued my journey. Parked the car up. Turned engine off and popped the bonnet. Had a look for obvious signs of diesel etc couldn't see or smell anything.

Started the car up and still nothing obvious, smell or otherwise.

Are diesel engines generally a bit smelly at the exhaust? Or does the car need to be checked out.

It's much more noticeable after I have had some "lead" in my right foot.