Judder and sulphur smell

imotepify

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Hi guys, just on our way out 4 a meal and the cel came on and then the DTM started 2 judder when accelerating and I could smell a strong smell of sulphur. I've switched the engine off and on a few times when the light began 2 flash then stayed off but still has the smell and judder. It's back home now but still playing up :( any ideas?
 
if you notice a sulphur smell then it will most likely be a cat converter issue, I no expert on the subject by any means but our old 1996 Renault clio had a terrible sulphur odour a lot of the time , turned out to be the cat converter starting to fail, maybe a good idea to run vcds and get the system checked for possible start of a bigger problem.
 
this may clarify it more.

Any type of engine smell is a bad sign, no matter what type of smell it is. A certain engine smell can be caused by a specific problem in your car. It is important you understand and know what each smell signifies and how you can fix them.
Types of Engine Smells

If your engine has problems, it might provide a certain kind of smell. Each smell can equate to specific problems in your engine. A burning engine smell like burned toast, which often emits a sharp, light odor, may be due to the insulation of your car burning or an electrical short.

Another common smell is similar to rotten eggs. Unless you have rotten eggs in your car, this smell is a burning sulfur smell which is a clear symptom of a catalytic converter problem in your engine, or damage in the emission control system. It may also mean that your engine is running with a rich air/fuel mixture.

If your engine emits a chemical odor or burning resin, then this may be due to an overheated clutch or brakes. On the other hand, a steamy, sweet odor is due to a leak in the coolant system.

Effects of Engine Smell
Once you can smell a different odor emitting from your engine, it is time to do some investigation and bring your car to a professional or do the necessary repairs. It is important to remember these smells mean there are damages or malfunctions to parts of your engine that need to be repaired.

Since each smell is due to a certain engine problem, it is important you immediately fix it. Otherwise, your car’s engine and overall performance will be affected.

Having a rich air/fuel mixture can cause your car to produce a higher level of carbon monoxide, which in turn can increase the production of carbon dioxide. This also means there is a leak in the injectors, the oxygen sensor is contaminated, or fuel pressure on the engine is excessive.

Although troubles in the catalytic converter may be hard to diagnose, the smell it emits is a surefire way of determining there really is a problem you need to address. The catalytic converter is a part of your car’s exhaust system, which converts harmful compounds to harmless ones.

How to Fix Engine Smells
For engines emitting a burned toast-like smell, it is safer not to use the vehicle until the damage has been repaired. Bring your engine to a professional to rid of the auto repair smells. Fix the electrical short or the burnt insulation.

A sulfur smell means there is a problem with the catalytic converter. To fix this problem, cut the damaged converter on both ends. Make sure the engine is totally cooled before you do this. After cutting the old one, replace it with the new converter and tac-weld each end. Remember that any damage to the converter should be repaired as soon as possible.

Most overheating problems on the clutch or brakes can be easily fixed. Check the thermostat of your engine, and if this is the cause of the problem, replace the thermostat with a new one.
 
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Reactions: Sandra
Thanks for the reply, I'm sure it's more like a dis pack or spark plug maybe a sensor because of the other symptoms :( and the cel
 
unlikely to be spark plugs, the smell of rotten eggs is due to a compound called hydrogen sulfide. This comes from the small amount of sulfur that is present in the fuel. Normally the sulfur is converted to sulfur dioxide, which has no odor. When the converter breaks or the filtering layers have worn down inside the converter, the sulfur is not transformed into the odorless form. Therefore a strong rotten egg smell is produced. Another possible cause for this smell may be that the converter is plugged.
Unfortunately you cannot repair a converter but need to have it completely replaced. Two other causes of rotten eggs besides a broken catalytic converter include an engine that is running too hot or a broken fuel pressure regulator. You can easily deal with the fuel pressure regulator by replacing the fuel filter
 
I was thinking maybe unburnt fuel could be getting into the cat producing the smell from a faulty plug or coil/dis pack or the o2 sensor? Would this also make the car judder a lot under any revs?
 
have you access to vcds or a fault code reader, i'd run those first to bring up any fault code, if you had a CEL then there was fault and there will be a diag code.

possibly a sensor and overfuelling, the sulpur odor is a byproduct of the cat converter, but there may be another issue that is behind that.

coil packs if they haven't been changed possibly but not conclusive either.

I think rather than take less than 100% guesses you need to run diags to get a confirmed starting point and work bck from there chap, sorry cant be any more precise.
 
Thanks for the help, I will get it 2 my local garage on Monday but will need the AA as can't drive it like that lol
 
you are not alone chap, if you do a web search you see a lot of very similar if not the same problems with audi's and not just a4's , most seem to suggest numerous solutions but never really point at one specific problem hence why its best you get it scanned to get an accurate point of ref and work from that.
good luck with it chap.

rob
 
Could be running rich. First thing I'd be looking at is intake integrity (check for unmetered air/leaks) and plausibility of fuelling-critical signals (coolant temp, load signal, etc).
 
Was the coil pack, thanks for the help guys :)
 
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Reactions: Charlie Farley
did you get them done under warranty as they are a recal item.
 

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