Xantia - Bad smell from the exhaust system

lancia58 · Post by **lancia58** » 16 Jul 2011, 12:49

My Xantia SX is 2.0 16v petrol automatic. There is a noticeable smell from the exhaust system. The fuel consumption at the freeway is OK for a car of that age ( make year 2000 ), about 30 mpg. The urban consumption ( I live at a hilly place ) is about 17 mpg. Last time I changed the plugs ( 3 month ) the electrodes looked OK and it passed the MOT emission test on January. This smell has been since I bought the car on March 2010. The car has 80K miles. Any suggestion how to track down this ? Given I have a Lexia 3 how can it be used to narrow the search for possible causes . When I start the car and the engine is cold it starts to smell after the engine warms up.

Thanks
Zohar

Timmo · Post by **Timmo** » 16 Jul 2011, 13:15

what sort of smell?? if its wrotten egg type smell / surphery then could point to Cat issues???

Jaf · Post by **Jaf** » 16 Jul 2011, 13:17

What sort of bad smell is it? If it's an "eggy" smell it could be as simple as changing the brand of fuel you buy.

Post by **Peter.N.** » 16 Jul 2011, 15:12

If it only occurs when cold it could be normal.

Peter

lancia58 · Post by **lancia58** » 16 Jul 2011, 16:32

The closest smell I can think of is burnt kerosene. The smell is noticeable when the engine is warming up. It is not noticeable when the engine is cool.

Thanks
Zohar

Post by **myglaren** » 16 Jul 2011, 16:34

Any smoke with it? Is it using oil?

handyman · Post by **handyman** » 16 Jul 2011, 17:25

There is a chance that it is unburnt ethanol as this is now being added in ever greater quantities to petrol under some EU directive.

I have noticed the same thing recently with a couple of my cars which leads me to believe it is a petrol issue. It only exists during the warm-up phase and smells like unburnt fuel or an over-rich mixture, once the engine has reached its normal running temperature it disappears.

I have done a bit of research on this as some of the British Standards have been superceded to allow 5%, E5, or 10%, E10 addition of ethanol to the base fuel as some way to reduce the manufacturing costs of petrol and give some supposed 'green' benefit.

There are a lot of downsides in the use of ethanol, not least internal fuel system corrosion, even on cars only five years old!

In addition, the calorific value of the fuel is significantly reduced, so the MPG drops, so you buy more fuel. Nice little earner for HMG, Terry!

I have got a few bits of info on this, mostly gleaned from sources on t'Net, but I can post up links for interested parties.

I am not sure how it affects our kerosene loving brethern though.

H

Post by **myglaren** » 16 Jul 2011, 17:32

handyman wrote:
I am not sure how it affects our kerosene loving brethern though.

H

I have noticed recently that my HDi recently smells vaguely alchoholicy on start up, not the usual diesely smell.

On Bio it smelled much better than on standard diesel but that was a few years ago now.

Wasn't aware that they were adding ethanol to diesel, thought it was just petrol.

handyman · Post by **handyman** » 16 Jul 2011, 17:41

Hi Steve, when I was in France recently, I noticed the diesel pumps there were displaying the E10 nomenclature, as I wanted to see how far the rot had travelled. If France has got it, chances are its here already.

Bit like 'Invasion of the Body Snatchers' but different.

Are you sure that alcoholicky smell is from the exhaust? That Newcastle Broon takes awhile to burn off.

H

Post by **myglaren** » 16 Jul 2011, 18:14

handyman wrote:
Are you sure that alcoholicky smell is from the exhaust? That Newcastle Broon takes awhile to burn off.

H

That's a thought!

Actually no though, never touch the stuff and in fact I think it is deceased - the breweries are either closed or multi-story carparks now.

lancia58 · Post by **lancia58** » 16 Jul 2011, 18:57

It is not the fuel quality or compounds , other Xantias don't have this kind of smell. At first I tended to believe it smells like an over rich mixture but as it passed the MOT emission test I guess it is not. One important thing I forgot to add is that there is a light black deposit on the rear bumper right above the muffler.

Thanks
Zohar

addo · Post by **addo** » 16 Jul 2011, 23:24

I'd suggest you test the compression; it may be burning a little oil.

Also watch the voltage of your oxygen sensor with Lexia - it should jump in four or five steps from about 200 to about 900-950.

You are using a well-known brand fuel, or a discount variety?

lancia58 · Post by **lancia58** » 17 Jul 2011, 05:11

I check the oil level frequently and it is very stable and actually indicates that there is no oil leakage. Between two consecutive oil changes even not a single gram is missing. I do not use discount fuel. Can a minor failure in the FPR be the cause ? Is there a way to test the FPR ? Anyway I’ll check the oxygen sensor and post the result.

Thanks
Zohar

lancia58 · Post by **lancia58** » 23 Jul 2011, 16:36

After re-smelling I am almost sure it’s a smell of petrol. Maybe the mixture is too rich, but the fuel consumption is very good. I retested it just to make sure and on the freeway it is 34mpg which is very good. Urban consumption is 17mpg, I guess the big difference between urban and freeway consumption is because I live in a hilly town. It is strange that the fuel consumption is OK and at the same time there is a smell of petrol getting out of the muffler. Any ideas ?

Thanks
Zohar

lancia58 · Post by **lancia58** » 28 Jul 2011, 13:48

Hi

I checked the Oxygen sensor using the Lexia, the voltage jumps form 150 to 800 but it was very erratic. For example I recorded the following consecutive readings 776, 561, 439, 732, 195, 664, 156, 644, 146.The engine was at idle. Is that a normal behavior or it indicates a faulty Oxygen sensor ? Is there one Oxygen sensor or more ? The car engine is 2.0 16v

Thanks
Zohar