Audi a3 1.6 8v 1998 AKL a lot of exhaust smoke

[Christian]

Hi everyone on the ericthecarguy forum!

I own an Audi a3 1.6 8v enginecode AKL year 1998 that I’ve had a problem with since a few months back which is that the car has a lot of exhaust smoke when the engine is warm/at operating temperature. The car smokes a lot when it’s idling and also when revving and you can see it if the car is at standstill and you rev that the exhaust smoke is increased a little but what gets me the most is that the car smokes a lot at idle which I find is no good because I really like the car as it works perfectly fine otherwise. It revs wonderful on first, second and third gear(understandable as it is only 100hp engine) and it is also incredible easy to start even if the car has been sitting a longer period. The only problem I find the car a little difficult to start is when I accidentally stall the car but I guess that’s normal for this engine? The car has done 300000km which converted is 186411 miles. I used to have a coolant leak that caused loss of coolant in the coolant reservoir which I repaired by replacing the famous and common coolant flange that cracks and leaks. After the replacement for a new one I’ve got no more coolant leak and no more loss of coolant. When I smell the exhaust smoke it doesn’t smell sweet and it doesn’t smell like burnt oil but it does smell a little like unburnt petrol. I also know that I have an exhaust leak but an exhaust leak couldn’t make this kind of exhaust smoke, could it?

So what have I done to the car in terms of diagnose and replacing parts?
Well.. I have used Autocom to scan the car for errors, especially in engine management but the scan came up with no errors/dtc. 2 months ago or so I have changed the spark plugs, HT-leads because of a misfire that I was having, I’ve changed airfilter, temperature sensor that sits in the coolant flange at the side of the head, the hose between the airfilter housing and the throttle body, I’ve cleaned the throttle body and done an adaption/alignment because the revs were at 1400-1600 rpms and badly hunting after the cleaning but the revs are now stable at around 800 rpms. I’ve also changed the thermostat, cleaned the MAF-sensor, changed the oil and oil filter. That’s about it what I’ve done to the car so far in terms of parts and diagnose.

I’ve recorded the exhaust smoke from my car and uploaded it to youtube, you can watch it by this link: https://www.youtube.com/watch?v=2Ywhj03mpa8

At the moment I don’t know how to proceed in terms of diagnosing this problem. I’m hoping that some of you might have owned or repaired either an Audi a3, Skoda Octavia or Volkswagen mk4 with the same type of problem that I have with my car.

Topic

[Josh]

You’re probably burning oil and/or your catalytic converter is no longer absorbing exhaust byproducts as it should………..which is pretty normal for a car of that age.

Ensure your vehicle isn’t running rich, or consuming oil and look into replacing the catalytic converter if the first two are ruled out.

[Dave Tidman]

You may want to bounce this off Humble Mechanic http://humblemechanic.com/.

He is a VW tech and does weekly podcasts where he answers questions.

[Mike]

I would do a compression test on all cylinders. It’ll tell you if you have a piston ring/worn cylinder bore issue.

[Christian]

Thanks for The suggestions, I’ve talked with a mechanic who thinks that due to me not driving a lot and often not accelerating The car hard that there might be a lot of water in the exhaust system which cause all this smoke at idle and therefor the smoke doesnt smell anything so it is just probably “tons” of water/condense due to calm driving and short distances of driving on daily basis. So I will floor it really hard on The highway and hope that it solves The problem by emptying The exhaust from all condense.

I think I will also check the CO and HC values and see that they are good and within certain specs so to speak

[Christian]

A quick update since last post:

After driving the car on the highway and revving it hard and then slowing down and stop the car to go outside and see if there was any exhaust smoke there wasn’t any at the moment when the car was idling but it did smell like rotten eggs. I decided to head back home again and when I parked the car and let the car idling I noticed that the problem reappeared with a lot of exhaust smoke and the smell of burnt eggs and I also noticed that when revving the car at standstill to about 5000rpm that I could hear a rattle. Does this mean that the catalytic converter has gone bad? Because what I know about catalytic converters is that when they go bad they make the car very weak in uphills because the loose parts inside the catalytic converter moves and clogs the exhaust system? Because my car doesn’t feel weak at all when driving on uphills but maybe that’s the cause of the exhaust leak that makes the exhaust gases escape through the leak instead so that the car won’t die/get weaker if the parts in the catalytic converter clogs up?

If that’s the case then I will have to look into a brand new catalytic converter because the used ones are as expensive as new catalytic converters since there are pretty cheap catalytic converters(brand new) on Ebay.

Here is a new video that I recorded when the car didn’t have any exhaust smoke at all, just a little exhaust smoke that seems normal for the age of the car: https://www.youtube.com/watch?v=TrpTFVyHkyg

[Ty]

Yep sounds like the cat is toast.

[Josh]

[quote=”christianswe24″ post=177613]A quick update since last post:

After driving the car on the highway and revving it hard and then slowing down and stop the car to go outside and see if there was any exhaust smoke there wasn’t any at the moment when the car was idling but it did smell like rotten eggs. I decided to head back home again and when I parked the car and let the car idling I noticed that the problem reappeared with a lot of exhaust smoke and the smell of burnt eggs and I also noticed that when revving the car at standstill to about 5000rpm that I could hear a rattle. Does this mean that the catalytic converter has gone bad? Because what I know about catalytic converters is that when they go bad they make the car very weak in uphills because the loose parts inside the catalytic converter moves and clogs the exhaust system? Because my car doesn’t feel weak at all when driving on uphills but maybe that’s the cause of the exhaust leak that makes the exhaust gases escape through the leak instead so that the car won’t die/get weaker if the parts in the catalytic converter clogs up?

If that’s the case then I will have to look into a brand new catalytic converter because the used ones are as expensive as new catalytic converters since there are pretty cheap catalytic converters(brand new) on Ebay.[/quote]

1: It is federally illegal to install a used cat in the United States. I don’t know about EU or Canadian regulations but I would imagine that they have similar if not stricter regulations. That you used KMs as your initial unit of measure and the fact that the A3 1.6L Audi wasn’t sold in the US in 1998 leads me to believe that you aren’t writing from the U.S.

2. For critical parts relating to the emissions, engine, safety or any other system please use parts specifically designed for your vehicle and not generic eBay or “universal fit” parts. The Cat is one of those parts that falls under the heading of critical to the function of the vehicle and many non-U.S. nations require you to keep your vehicle in environmental compliance with the OEM specifications to pass environmental and/or safety inspections (i.e. MoTs in the UK). That said the final choice in parts is up to you

[Christian]

[quote=”jonsey1886″ post=177618][quote=”christianswe24″ post=177613]A quick update since last post:

After driving the car on the highway and revving it hard and then slowing down and stop the car to go outside and see if there was any exhaust smoke there wasn’t any at the moment when the car was idling but it did smell like rotten eggs. I decided to head back home again and when I parked the car and let the car idling I noticed that the problem reappeared with a lot of exhaust smoke and the smell of burnt eggs and I also noticed that when revving the car at standstill to about 5000rpm that I could hear a rattle. Does this mean that the catalytic converter has gone bad? Because what I know about catalytic converters is that when they go bad they make the car very weak in uphills because the loose parts inside the catalytic converter moves and clogs the exhaust system? Because my car doesn’t feel weak at all when driving on uphills but maybe that’s the cause of the exhaust leak that makes the exhaust gases escape through the leak instead so that the car won’t die/get weaker if the parts in the catalytic converter clogs up?

If that’s the case then I will have to look into a brand new catalytic converter because the used ones are as expensive as new catalytic converters since there are pretty cheap catalytic converters(brand new) on Ebay.[/quote]

1: It is federally illegal to install a used cat in the United States. I don’t know about EU or Canadian regulations but I would imagine that they have similar if not stricter regulations. That you used KMs as your initial unit of measure and the fact that the A3 1.6L Audi wasn’t sold in the US in 1998 leads me to believe that you aren’t writing from the U.S.

2. For critical parts relating to the emissions, engine, safety or any other system please use parts specifically designed for your vehicle and not generic eBay or “universal fit” parts. The Cat is one of those parts that falls under the heading of critical to the function of the vehicle and many non-U.S. nations require you to keep your vehicle in environmental compliance with the OEM specifications to pass environmental and/or safety inspections (i.e. MoTs in the UK). That said the final choice in parts is up to you[/quote]

I’m from Sweden actually and in Sweden it is totally legal to use a used catalytic converter because I know plenty of people that bought one used an installed, went to the mot and got the car approved for 1 year further as long as the exhaust values of CO and HC are within the tolerance but the problem is that used catalytic converters is usually in a bad condition with high milage and it’s always a risk buying a used part. By using oem number from shops in Sweden that sells spare parts for cars I have found the exact same part cheaper in Ebay. It’s very expensive to buy spare parts for cars in Sweden.

[Josh]

As long as it’s an OEM part/part specifically designed for your model of vehicle eBay is fine.

Note I said “generic or universal fit” parts.

[Author]

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