Volkswagen Eos Forum banner

1 - 20 of 24 Posts

·
Registered
Joined
·
76 Posts
Discussion Starter #1
I have been having an ongoing issue with the CEL for three years. In 2016 the EPC light came on and the dealer determined it was the low pressure fuel pump. It was replaced and they also replaced the #3 injector (under warranty), as it was sticking open. In March of 2017 the car was running very rough and the CEL was on. The dealer replaced the #4 injector (again under warranty). Three weeks later car was ran rough with an EPC code. Dealer cleared codes, and test drove. Car drove fine and the code did not return. July 2017 CEL is back on dealer found the map sensor for the secondary air system was not sending correct signal and the kombi valve was not moving and is sticking. wanted to replace secondary air pressure sensor and kombi valve. I had the kombi valve sensor replaced at my local repair shop. The CEL came on again in August of 2018. I replaced the PCV, but it still has fault code P2431(Autozone). The car runs fine but I can not get a clear picture of what is wrong. Goodyear wants to replace the secondary air injection pump. I took the car to another repair place and they say the pump is working (and I could hear it running), but can not determine the exact issue. Ideas?
 

·
Registered
Joined
·
785 Posts
P2431 is a generic OBD code. VW-specific diagnostics should give you a five-digit number and will tell you more details about the issue - as you can see from what the dealer told you regarding the sensor not sending the correct signal.
 

·
Registered
Joined
·
5,375 Posts
I looked at the start of your troubles and scenarios which might have caused the first problems. Fuel injectors and pumps are usually pretty reliable and should run for thousands of miles. One random failure would be unusual, but two suggests something else is going on? In all the gas and diesel cars I've owned I've never replaced a fuel injector under 100k miles.:confused:

Have you thought about whether you might have contaminated dirty fuel and considered flushing through the fuel system and replacing filters?

If you aren't running decent diagnostics with helper files you are in the hands of your repair shop who will have better kit and experience. Cheaper diagnostics will just spit out a stored error code and not much more. Decent diagnostics kit will have some real time monitoring of engine performance variables which makes it a more useful tool if you know how to use it and interpret the results.
 

·
Registered
Joined
·
76 Posts
Discussion Starter #4
I looked at the start of your troubles and scenarios which might have caused the first problems. Fuel injectors and pumps are usually pretty reliable and should run for thousands of miles. One random failure would be unusual, but two suggests something else is going on? In all the gas and diesel cars I've owned I've never replaced a fuel injector under 100k miles.:confused:

Have you thought about whether you might have contaminated dirty fuel and considered flushing through the fuel system and replacing filters?

If you aren't running decent diagnostics with helper files you are in the hands of your repair shop who will have better kit and experience. Cheaper diagnostics will just spit out a stored error code and not much more. Decent diagnostics kit will have some real time monitoring of engine performance variables which makes it a more useful tool if you know how to use it and interpret the results.
The two injectors were replaced because VW deemed them faulty and extended their warranty to 100K miles. I was hoping to get the other two replaced, but VW will not replace until they go bad. The car is currently at a local repair facility and has been for 4 days. After talking with them yesterday it appears they do not have decent diagnostic software. The mechanic, who owns a GTI and seems very versed with VW's, has been using his personal software but seems stumped. I talked with him about how the dealer wanted to replace the secondary air pressure sensor and kombi valve two years ago. I took it to my local repair place at the time and their Ross-Tech diagnostic said only the sensor was bad, which they replaced. Could the kombi valve be bad? Would it throw a specific code?
 

·
Registered
Joined
·
5,375 Posts
OK maybe they know something about that batch of fuel injectors they haven't told you? Modern fuel injectors are usually very reliable but there are 2 ways they can fail: First is blockage or seizure caused by bad fuel or water in the gas. Most fuel injectors have a fine gauze filter inside but that's a last resort if the fuel filter isn't doing its job. The second way they can fail is open circuit solenoid coil which is easy to check. That can fail if the area around the injectors is always very hot.

I use vcds and that gives real english descriptions of what 'might' be wrong. This often comes from the many contributors on the Ross-Tech site. It's hard just using a fault code to advise somebody to spend a lot of money replacing a part when the fault could be somewhere else. Interpreting diagnostics information needs experience and skill because what they may appear to say is wrong could be other things like dependent parts, wiring or connectors?

If I see a diagnostics fault code and unlike a Dealership that may charge up for parts that weren't faulty, I need a second means of confirmation. But I have the knowledge and skills to poke around with a multimeter, 'scope and sewing pins to apply first line fault finding before replacing a part. That could take me a couple of hours and most would not pay for that labor time.

In my experience, if you start suggesting things to workshops they will tell you what you want to hear. Tricky faults whilst more expensive, are best dealt with at the dealer, particularly if there could be a warranty claim or history of unreliability from buying new? Unlike the independent workshop, they have the right diagnostics equipment and a huge database history from other vehicles to look up. Even if a V.W Dealer regards your car as out of warranty, they may offer 'Goodwill' options as your car is so new? IMHO Manufacturers may try to hide component reliability problems for repairs during the warranty period, but they will have history which the independent hasn't got.
 

·
Registered
Joined
·
76 Posts
Discussion Starter #6
OK maybe they know something about that batch of fuel injectors they haven't told you? Modern fuel injectors are usually very reliable but there are 2 ways they can fail: First is blockage or seizure caused by bad fuel or water in the gas. Most fuel injectors have a fine gauze filter inside but that's a last resort if the fuel filter isn't doing its job. The second way they can fail is open circuit solenoid coil which is easy to check. That can fail if the area around the injectors is always very hot.

I use vcds and that gives real english descriptions of what 'might' be wrong. This often comes from the many contributors on the Ross-Tech site. It's hard just using a fault code to advise somebody to spend a lot of money replacing a part when the fault could be somewhere else. Interpreting diagnostics information needs experience and skill because what they may appear to say is wrong could be other things like dependent parts, wiring or connectors?

If I see a diagnostics fault code and unlike a Dealership that may charge up for parts that weren't faulty, I need a second means of confirmation. But I have the knowledge and skills to poke around with a multimeter, 'scope and sewing pins to apply first line fault finding before replacing a part. That could take me a couple of hours and most would not pay for that labor time.

In my experience, if you start suggesting things to workshops they will tell you what you want to hear. Tricky faults whilst more expensive, are best dealt with at the dealer, particularly if there could be a warranty claim or history of unreliability from buying new? Unlike the independent workshop, they have the right diagnostics equipment and a huge database history from other vehicles to look up. Even if a V.W Dealer regards your car as out of warranty, they may offer 'Goodwill' options as your car is so new? IMHO Manufacturers may try to hide component reliability problems for repairs during the warranty period, but they will have history which the independent hasn't got.
I was told 4 years ago VW extended the warranty on a batch of injectors to 10 years or 100K miles. Is there any way for me to determine if the kombi valve is working correctly? Since the dealer 2 years ago recommended this and the sensor be replaced, I'm thinking that is the place to start. Any tutorial available on how to replace the kombi valve?
 

·
Registered
Joined
·
5,375 Posts
You can try a Google search? Although I try to refer to a VW workshop manual instruction first. This may need more comprehension but they don't take short cuts. You may get lucky on a replacement, but if not you will still be chasing your tail unless you understand and use decent diagnostics as a proper fault finding tool. I already told you that a decent diagnostics tool has 'measuring blocks' that can give realtime results whilst an engine is running. But it sounds as though you want a simple go or no go solution to a problem the ECM considers serious?

The worst scenario is spending loads on parts that weren't faulty, then give up and have a competent dealer tech. solve your problem. :( Add up the cost of parts you bought and aggravation, then the price for a dealer to fix (with warranty!) doesn't then seem that expensive. :confused: It can get worse because if you sourced cheaper non-OE replacement parts incompatible for your VIN, a tech. will be scratching their head and adding on more expensive fault finding time.

Be aware that some CEL faults can after X kilometers put your car into limp home mode which you will love. In this case, a fault with exhaust air circulation will affect the life of your CAT and I suspect this could be one of the high priority faults that would give you the dreaded limp home and 'Take to Garage' message on the dash. :eek:
 

·
Registered
Joined
·
76 Posts
Discussion Starter #8
You can try a Google search? Although I try to refer to a VW workshop manual instruction first. This may need more comprehension but they don't take short cuts. You may get lucky on a replacement, but if not you will still be chasing your tail unless you understand and use decent diagnostics as a proper fault finding tool. I already told you that a decent diagnostics tool has 'measuring blocks' that can give realtime results whilst an engine is running. But it sounds as though you want a simple go or no go solution to a problem the ECM considers serious?

The worst scenario is spending loads on parts that weren't faulty, then give up and have a competent dealer tech. solve your problem. :( Add up the cost of parts you bought and aggravation, then the price for a dealer to fix (with warranty!) doesn't then seem that expensive. :confused: It can get worse because if you sourced cheaper non-OE replacement parts incompatible for your VIN, a tech. will be scratching their head and adding on more expensive fault finding time.

Be aware that some CEL faults can after X kilometers put your car into limp home mode which you will love. In this case, a fault with exhaust air circulation will affect the life of your CAT and I suspect this could be one of the high priority faults that would give you the dreaded limp home and 'Take to Garage' message on the dash. :eek:
Thanks for the help. I talked with my local dealer and they only charge $90 to diagnose a CEL. I think I am going to do this, but would like to clear all the stored codes prior to taking it to the dealer. Over the past few weeks I have made a few simple repairs and cleaned several sensors. I believe there is very little chance I actually fixed the problem, but would like to remove all stored codes prior to having the dealer scan the car. There is probably also and engine mis-fire code stored after I replaced the plugs and coil a few months ago. Short of buying an OBD scan tool, is there a way to erase the codes?
 

·
Registered
Joined
·
785 Posts
Short of buying an OBD scan tool, is there a way to erase the codes?
No. You want a VAG-specific tool like VCDS, OBDeleven or even a hand-held VAG scan tool. But don't worry, it will pay for itself over the lifetime of your Eos ;)
 

·
Registered
Joined
·
5,375 Posts
If somebody brought a car to me to fix having erased fault codes I would be pretty miffed because my diagnostics work would be made a lot harder and a fault could stay hidden. The ECU stores information about when the last fault codes were cleared! You may want to erase what you think is irrelevant, but you don't have the same level of knowledge or experience? Erasing codes doesn't always work on a CEL fault because they generally come back.

If you start using diagnostics for DIY repair you have to learn the whole deal. It's not always as simple as reading out/clearing a fault code then look for a solution on the internet. In the wrong hands, professional level diagnostics tools can brick a car, equivalent to Blue Screen of Death. :(

What you should do is get your car scanned as it is with a print out, then ask THEM to clear the fault codes, drive the car a mile, then rescan and provide the results copy. If they offer advice, listen!.
 

·
Registered
Joined
·
76 Posts
Discussion Starter #11 (Edited)
If somebody brought a car to me to fix having erased fault codes I would be pretty miffed because my diagnostics work would be made a lot harder and a fault could stay hidden. The ECU stores information about when the last fault codes were cleared! You may want to erase what you think is irrelevant, but you don't have the same level of knowledge or experience? Erasing codes doesn't always work on a CEL fault because they generally come back.

If you start using diagnostics for DIY repair you have to learn the whole deal. It's not always as simple as reading out/clearing a fault code then look for a solution on the internet. In the wrong hands, professional level diagnostics tools can brick a car, equivalent to Blue Screen of Death. :(

What you should do is get your car scanned as it is with a print out, then ask THEM to clear the fault codes, drive the car a mile, then rescan and provide the results copy. If they offer advice, listen!.
Are you saying that if the CEL comes on and the issue is repaired, the code would come back?

I understand what you are saying about erasing the codes. I was just trying to avoid the unlikely event of paying the dealer $90 and having them tell me there are no current codes.
 

·
Registered
Joined
·
5,375 Posts
Are you saying that if the CEL comes on and the issue is repaired, the code would come back?
Not quite. An experienced technician will scan a car and save the first scan. Engine diagnostics can sometimes throw up spurious fault codes, often when batteries are changed or if there are interference spikes. Therefore faults seen on the first scan may not be real.

The technician will then clear those fault codes, turn on the ignition and re-scan. Faults that have already been fixed, or phantom codes should clear leaving only 'Real' fault codes relating to the present situation. Then the technician will start the engine and may take the car for a short drive. Emissions related problem, bad CATs or Dpfs may not show up again until the car is hot and being driven. If after a drive test there are no faults showing and the CEL light stays out, they have probably done what they can for the labor you are prepared to pay for. But it doesn't guarantee your car is completely fault free.

Two weeks later (say) your CEL light comes back on. That scan is crucial for the technician because it will be saying there's an intermittent type fault to look further into. Once you start clearing fault codes just to put out the CEL light, you make finding your problem by somebody else a lot worse.

Look at it this way, you aren't paying a dealer just to clear codes, you are asking for help to solve your problem which may still be there, using evidence from the scans. One thing I didn't say is a fault code has information attached as to the mileage and frequency of the fault. A type of fault that has occured 50 times in 500 miles will probably be real. Erasing the fault code also erases information about when and how often it has been ocurring. That is how you identify misfire problems with coils. The same fault code shows up, but if there have been many repeated fault events its not just a random thing.

That same history of fault ocurrences is helpful when a dealer hands back your car. If the same fault comes back with several more repeated events, they haven't found the problem yet even though you might have been charged for replacement parts.
.
 

·
Registered
Joined
·
76 Posts
Discussion Starter #13 (Edited)
So the dealer did the scan and it seems the secondary air pressure pipe is leaking. I can not seem to find a diagram of the secondary air system to see exactly where this is. Does anyone know where a diagram might be?

Also, there were codes P0300, P0301, P0302, P0303 and P030, which they suggests there is carbon build up on the intake valves. The did not recommended removing the intake manifold. They recommended some type of additive that cost almost $500. I thought they gave me that info, but they didn't. Has anyone every heard of this? I found a TSB a few months ago where VW recommended a VW fuel additive, but I don't think this is it.

https://static.nhtsa.gov/odi/tsbs/2014/SB-10069597-2280.pdf
 

·
Registered
Joined
·
5,375 Posts
I had similar type problems with a diesel at 60K. I decided to remove the (plastic!) inlet manifold assembly and was amazed at the amount of carbon sludge/gunge and build up which I would not expect to be fully removed with an additive. I know mine was a dirty diesel, but whilst we all like to think squirting some magic stuff is a quick fix, I have rarely found it works in the long term. The problem is you don't really know the extent of the problem until you physically look and neither do you know if the expensive additive has been the long term solution.

I liken this to 'drain cleaning' . You buy some caustic drain cleaner and if you are lucky some of the blockage is removed. But later it comes back when it can be seen with a snake camera and only physical intervention cures the problem.
 

·
Registered
Joined
·
76 Posts
Discussion Starter #15
I had similar type problems with a diesel at 60K. I decided to remove the (plastic!) inlet manifold assembly and was amazed at the amount of carbon sludge/gunge and build up which I would not expect to be fully removed with an additive. I know mine was a dirty diesel, but whilst we all like to think squirting some magic stuff is a quick fix, I have rarely found it works in the long term. The problem is you don't really know the extent of the problem until you physically look and neither do you know if the expensive additive has been the long term solution.

I liken this to 'drain cleaning' . You buy some caustic drain cleaner and if you are lucky some of the blockage is removed. But later it comes back when it can be seen with a snake camera and only physical intervention cures the problem.
I agree that if this is a real issue with carbon build up a chemical solution will probably have no effect. Which makes me question this dealer. According to their diagnostic the secondary air pressure pipe is leaking. Since I have no idea where this pipe is, I can not verify what they are saying is true.

Have you had any experience with the VW/Audi fuel additive (G 001780M3)?
 

·
Registered
Joined
·
5,375 Posts
I have only used an aftermarket additive to give me a marginal improvement on a CAT (gasoline) which had just failed annual emissions test. :( The tester told me many run their tanks down to 1/4 and put this STP stuff in to get a pass. The following year I tried a quart of ethanol in a 1/4 tank and got a pass on the same CAT.

All I'm saying is there are plenty of horror stories of gummed up parts on diesels and the amount of gunge might reduce enough to put out a CEL light, but it won't last. Only when somebody gets their hands dirty and tears down parts can you be sure. I don't have your engine so can't help on location.

If V.W start using additives for a fix like excessive carbon, it sounds like they want to shield their customers from the real cost of taking parts off and doing a proper job? :confused:
 

·
Registered
Joined
·
76 Posts
Discussion Starter #17
The dealer install the kombi valve pipe on Wednesday and the CEL came back on Thursday. I took it to Autozone and Advance and both said it was still the secondary air injection system. The dealer is going to look at again on Tuesday and they want to keep it for a few days. They have already started saying it could be that since the system is now getting full pressure it may have brought out other issues in the system. It appears the original diagnosis of a leaking kombi valve pipe was done by a visual inspection. How specific is the VAG COM software? I'm worried this is going to be a rabbit hole and I have no reasonable expectation the next fix will work.

Also I bought a bottle of the VW/Audi fuel additive, put it in and ran on the highway at 5K RPM. After about 3 miles the EPC light went on and the engine sounded like a cylinder was not firing. I got off the highway and turned the car off and went to look under the hood. Nothing seemed to be off. I started it back up and no EPC light and the car ran fine. I am assuming a fuel injector was stuck open. This has happened to me twice and two injectors have been replaced under the VW extended warranty. When the dealer does a scan, will the EPC fault code appear? If so, if it was an faulty injector will it list the correct cylinder?
 

·
Registered
Joined
·
5,375 Posts
VCDS like any other diagnostics software is a tool. It's not mean't to tell you exactly what's wrong only to buy an expensive part and find the same fault comes back! That's why dealers charge you a lot of money for their labor because they are using their experience, diagnostics and a database of similar V.W faults which independents do not have. It's not quite artificial intelligence, but similar. VCDS is only a messenger and its results require experience to understand them, the possibility of consequential faults causing the same problem and technician techniques to intervene and change things then look again at the results.

The CEL light on V.Ws can be activated by many things (more than 1) and whilst vcds may give up some good 'clues', it requires good fault finding skills to go further. A genuine VW dealer is more expensive but should be best placed to properly diagnose your problem. :confused: Independent workshop chains will most likely have the same mindset as yourself - expect diagnostics to tell them EXACTLY what is wrong so they can fix it without experience on your car model. Fault finding difficult faults is not always that simple! A 10 year old kid can plug in diagnostics and get a result, but it's what they understand about the message and how to deal with it that counts. You and others are only looking at diagnostics codes, but vcds has a lot of live monitoring capability which helps when people know what to do with it and interpret the results.

You seem to me making assumption without evidence? Your ECU logs faults and if you 'think' there is a fuel injector problem, that error should have been stored and can be read. But it's only an error message from an event lasting some short time. You could have a problem with injector wiring or electronic control and the engine fault management may not know the difference!

IMHO intermittent 'soft' faults putting on the CEL can be affected by engine temperature or engine running time not hard wiring faults but sticking or fould up engine parts in the emissions control system? Motorized flap valves could have worn intermittent angle sensors and diagnostics won't give the exact fault. Then somebody needs to avoid the spray in temporary fix and start removing and inspecting parts. If your shops don't have the skills to do this, then they probably aren't the right people to use diagnostics tools and go much further?
 

·
Registered
Joined
·
76 Posts
Discussion Starter #19
Thanks for your advice. I have another appointment on Tuesday with the dealer. This time they want to keep the car. We will see.

I pulled the plugs this morning and it appears the plugs I just installed a couple of weeks ago are the incorrect plugs. When I did a google search for plugs I found the ones I have seem to be a colder plug. So I will be taking these back. Am I correct to assume a colder plug with foul out easier at high RPM's (such as what I was doing when the EPC light came on)? Of course I doubt a fouled plug would completely stop working (when I was on the highway) and then start working again (after I restarted the car). To me this sounds more like a stuck injector. The second injector was replaced after hard acceleration and the injector was stuck open. But with that injector it did not close after a restart.
 

·
Registered
Joined
·
5,375 Posts
I wouldn't expect the heat range of plugs to make a lot of difference such that you would notice for normal driving and standard fuels. If the engine was tuned and you were red lining the rpm all the time, then yes it could make a difference. If you are getting a dealer to look at it, it gives them an excuse to say wrong plugs might be causing problems, so get the correct plugs.

The way to check a suspect injector is to scan first with diagnostics to confirm the injector number then swap it to another position. If the fault re-occurs on the injector you swapped then it is suspect, if it stays with the same cylinder then suspect the wiring and control. As I explained, fault finding is a human skill and diagnostics does not do that yet, although AI supported by a lot of human gathered fault data and repairs might in the future?

You haven't mentioned this but on these gasoline engines it seems common to have the spark plug coils go intermittent and fail.:( I have diesel and can't look into this, but I suspect the individual coil packs may get too hot located where they are and the coil insulation breaks down. :confused: I don't think they are too expensive to replace the lot with genuine Bosch parts?

I can't understand why solenoid operated injectors should be failing to stick open unless there is a fuel contamination problem. Adding a fuel additive may help, but non of my injection vehicles have had this problem.
.
 
1 - 20 of 24 Posts
Top