Audi A4 B6 2.0 liter ALT engine starting problem

[ernestank]

Audi A4 B6 2.0 liter ALT engine starting problem. 2003 Model with 190 000 Km.
Looking for a lot of help on trouble shooting a starting issue.
I have had the following replaced: the fuel pump and filter, injectors, both Coolant temperature sensor and switch, Cam position sensor, crank position sensor, timing chain and tensioner, Inlet and outlet hydraulic valve lifters, valve housing and pressure relief valve, breather hoses, vacuum breather pipes, air intake valve, oil pickup in sump, new key, new thermostat. All original Audi parts!

Three independent technicians and two Audi service centres have tried to find the fault without success.
No fault codes are stored or shows up even after driving the vehicle for weeks. (Audi computers, VAG, etc.)
When the engine eventually runs it is 100%. I get 7 L/100km on the highway and 9l/100km in town driving.

After starting following long cranking the exhaust emits stinky petrol fumes.

When the engine is cold, it starts normal.
When the engine is hot and I switch it off and start it immediately, it starts normal.
When the engine is hot and I switch it off and leave it for about 10 minutes it starts but immediately dies. It then takes a long time of cranking (10 seconds +) before it will start again. It splutters and slowly picks up revs.
If car stands for an hour or more it takes 10 + seconds of cranking before the engine slowly splutters to life.

I have now resorted to shorter cranks (3 to 5 seconds) and most times the engine starts with the third or fourth try.
Thanks

[ernestank]

:zx11: Help please all the experts out there!!!:1zhelp:

[micheal balbrig]

It might be worth talking to a good vcds operator to see if problem can be looked at when it happens,that is if you can replicate it when required.
Something may show up as vcds is connected,before and during problem. (only an idea)

[Sam]

You've changed a lot of things but not the thermostat. If it's stuck on a hot temperature then you'll get the symptoms you're describing.

Get it scanned with VCDS but my guess would be a faulty 'stat.

Use genuine parts only.

[ernestank]

It might be worth talking to a good vcds operator to see if problem can be looked at when it happens,that is if you can replicate it when required.
Something may show up as vcds is connected,before and during problem. (only an idea)

OK where do I find a GOOD vcds operator? The car was connected to the Audi diagnostic computers as well as the indies diagnostics but no errors or problems or codes were indicated even though the engine would not start normally. The starting problem is easy to replicate it just takes time.

[ernestank]

mycarsavw (http://www.vwaudiforum.co.uk/forum/member.php?402-mycarsavw)



Re: Audi A4 B6 2.0 liter ALT engine starting problem
You've changed a lot of things but not the thermostat. If it's stuck on a hot temperature then you'll get the symptoms you're describing.

Get it scanned with VCDS but my guess would be a faulty 'stat.

Use genuine parts only.


Your guess is as good as mine, only I pay if you guess wrong.. and have I been paying! The thermostat was replaced 20 000 kms ago and works 100% All parts fitted are genuine Audi parts.
As I have stated no fault codes or problems are indicated by diagnostic software.

[Sam]

Your guess is as good as mine, only I pay if you guess wrong.. and have I been paying! The thermostat was replaced 20 000 kms ago and works 100% All parts fitted are genuine Audi parts.
As I have stated no fault codes or problems are indicated by diagnostic software.

Now that we know the 'stat is new(ish) and works, that can be ruled out. We didn't know that until just then though ;)

Back to the issue at hand, I'll ask someone who has forgotten more than most of us know and see what he says.

[Crasher]

Oo dat den.....

What sort of ambient temperatures is it being operated in?

What make and VAG part number ignition coils are fitted?

It is important to make sure the ECU is not suffering low voltage during cranking due to wiring corrosion problems.

[ernestank]

Oo dat den.....

What sort of ambient temperatures is it being operated in?

What make and VAG part number ignition coils are fitted?

It is important to make sure the ECU is not suffering low voltage during cranking due to wiring corrosion problems.

Current ambient temperatures are 0 to 20 deg C. The coils are original Audi, I shall try to read a part number from them and post it. How can I test the inputs to the ECU. My old Kadett had a test procedure with all the resistance values and voltage levels at different temperatures for all the various sensors where I could measure it at the ECU. Does anyone have this for the Audi? I have installed a new premium lead calcium battery about 6 months ago. A wiring diagram would help so that I may measure the wires for corrosion!

[Crasher]

Get me the coil numbers first.

[ernestank]

Get me the coil numbers first.

VW AG
06C 905 115L
PPM DE S3
Pulse 12433ESM
L1E733 1 04/09

I removed the Mass Airflow Meter (F 00C 2G2 049) and found that it did not have the thermistor as indicated on the picture. Is this correct?.
http://obrazki.elektroda.pl/1397520900_1316205438.jpg

[Crasher]

The 06C 905 115 L coils fitted to your car are acceptable under the conditions of the 28E9 recall so are probably not the reason for your problems. The part number on the outside of the Air Mass Meters main body should be VAG 06B 133 471 A, Bosch 0 280 218 058.

[ernestank]

The 06C 905 115 L coils fitted to your car are acceptable under the conditions of the 28E9 so are probably not the reason for your problems. The part number on the outside of the Air Mass Meters main body should be VAG 06B 133 471 A, Bosch 0 280 218 058.

The MAF inside main body Bosch F 00C 2G2 049. OK ANYone that can help with wiring diagrams? :confused:

[Crasher]

It is not normal practice to change the AMM insert, the number I gave you and the only number I have, is the one on the main body. If you have doubt's about the AMM, fit a genuine VW dealer supplied exchnage replacement as counterfeit Bosch units are very common.

[ernestank]

It is not normal practice to change the AMM insert, the number I gave you and the only number I have, is the one on the main body. If you have doubt's about the AMM, fit a genuine VW dealer supplied exchnage replacement as counterfeit Bosch units are very common.
OK sorry, we were sidetracked with the MAF. It was replaced by a Bosch Service centre Jan 2013. I shall verify the number and repost it but I believe that it should be correct. Back to the problem! Why does the car take long to start after it has been standing for a while?

[ernestank]

Any reply from your Gur?u?

[ernestank]

Now that we know the 'stat is new(ish) and works, that can be ruled out. We didn't know that until just then though ;)

Back to the issue at hand, I'll ask someone who has forgotten more than most of us know and see what he says.

Sorry..... Any suggestions from your GURU?

[Sam]

Sorry..... Any suggestions from your GURU?

He is the man helping you above ;)

[Crasher]

I wish I had a Guru for my back, ****in hurts......., I hate Mr Tramadol!:yawn:

The problem trying to help you is that you do not have your own diagnostic gear which will show Measuring Block information so it is difficult to suggest what to try without randomly swapping parts which is daft.

[ernestank]

I wish I had a Guru for my back, ****in hurts......., I hate Mr Tramadol!:yawn:

The problem trying to help you is that you do not have your own diagnostic gear which will show Measuring Block information so it is difficult to suggest what to try without randomly swapping parts which is daft.

OK so the AMM is a VAG 06B 133 471 A, Bosch 0 280 218 058. What I can not understand is that the AUDI Dealers could not locate the fault even with all their diagnostics! That is why I asked for a detailed wiring diagram with measuring specs so that I can find the fault the old way!
I accept that you would have it difficult and I appreciate your help tremendously :approve: but all I ask is to point me in some direction so that I may solve this problem.

[Crasher]

No, that's not right, if the AMM was replaced by a Bosch service centre, why does it have a VW part number on it? Proper Bosch units don't have the VW part number moulded into the body.

http://i222.photobucket.com/albums/dd20/Crasher1964/54b7463a-c3ed-47b1-9208-4e50a9861f4e_zps6c7777dc.jpg (http://s222.photobucket.com/user/Crasher1964/media/54b7463a-c3ed-47b1-9208-4e50a9861f4e_zps6c7777dc.jpg.html)

[ernestank]

No, that's not right, if the AMM was replaced by a Bosch service centre, why does it have a VW part number on it? Proper Bosch units don't have the VW part number moulded into the body.

http://i222.photobucket.com/albums/dd20/Crasher1964/54b7463a-c3ed-47b1-9208-4e50a9861f4e_zps6c7777dc.jpg (http://s222.photobucket.com/user/Crasher1964/media/54b7463a-c3ed-47b1-9208-4e50a9861f4e_zps6c7777dc.jpg.html)



This is what mine looks like. Bosch ordered the original parts from AUDI and fitted them. It cost me an arm and a leg!
24849:aargh4:

[Crasher]

That is perfect, from the way you said it with them being Bosch I had expected them to fit Bosch direct and they haven't, they have fitted a genuine AMM which I trust. I will send you the wiring diagram if you PM me your email, I hope you know how to follow a VAG current flow diagram, they are not schematic, just lines with numbers.

[ernestank]

That is perfect, from the way you said it with them being Bosch I had expected them to fit Bosch direct and they haven't, they have fitted a genuine AMM which I trust. I will send you the wiring diagram if you PM me your email, I hope you know how to follow a VAG current flow diagram, they are not schematic, just lines with numbers.

I'll give it a bash..:1zhelp: I sent you a PM. if you don't get it let me know please.

[ernestank]

I'll give it a bash..:1zhelp: I sent you a PM. if you don't get it let me know please.

:zx11: So I checked the wires as far as I possibly could and all seems OK! Unfortunately the problem is getting worse and now seems to be independant of temperature. IE it now battles to start all the time! :aargh4:

[Crasher]

So what fault codes are now re-occurring?

[ernestank]

So what fault codes are now re-occurring? :zx11: OK an update! Audi was at a specialist for two weeks. Fuel pump was removed and replaced. Old and new pump same problem. Fuel pressure (running and standing) is 100% All sensors were again checked. Timing etc 100%. Mechanic gave up saying he can not find the fault.:confused: NO FAULT CODES! Audi starts normal after standing overnight. Starts normal if hot and not switched off for more than 15 minutes. After 15 minutes the car will start normal and die immediately. Then 10 second crank gets it sputtering into life. If car stands for longer (hour or two) after driving I have to crank it for 10 seconds or more before it sputters slowly into life. Once the engine fires it goes like a bomb. No problem.....:1zhelp::aargh4:

[Crasher]

That is fuel vaporisation in the lines, some people call it percolation.

[Crasher]

What is the cars VIN, the part number of the old fuel pump and the part number of the pump they fitted?

[ernestank]

That is fuel vaporisation in the lines, some people call it percolation.

Sounds weird in a modern FInjection car:confused:

[ernestank]

What is the cars VIN, the part number of the old fuel pump and the part number of the pump they fitted?

The fuel pump assembly and injectors were ordered and supplied and fitted by an Audi dealership. I have to remove the pump to check the part numbers but I believe the parts are correct.
All the mechanical specialists have extensively tested (This was what I paid them for) the fuel supply, pressures, fuel filters, injectors, and as the whole fuel supply is new could it not be possible that it is actually functioning correctly and that they had done their tests and checks and balances correctly? Could it be something else? Could we explore that route?

[Crasher]

Why not? Fuel now is just as, if not more, volatile than it was int olde days, by gumm ohh ekk like, and will boil in an old car, new car or a baked bean tin, physics! If a liquid is under pressure, it will be less likely to boil than one at atmospheric pressure. If the valve that prevents the fuel pressure from bleeding back to the tank fails, the liquid can boil more readily. Alternatively, if the trigger system (on some cars) that makes the fuel pump run when you open the door, to prime the system, fails to operate, you will get can air lock of boiled fuel which can be stubborn to move. It is not so much of a problem as it was on the old K-Jet system where it prevented the injectors from cracking open but it can still cause problems. If your local fuel “brew” contains a high proportion of Ethanol this can contribute to this issue. In the UK we currently have E95 but soon we will have E90 snuck in under our noses without us being told and that is expected to cause issues with cars barley ten years old.

[ernestank]

Why not? Fuel now is just as, if not more, volatile than it was int olde days, by gumm ohh ekk like, and will boil in an old car, new car or a baked bean tin, physics! If a liquid is under pressure, it will be less likely to boil than one at atmospheric pressure. If the valve that prevents the fuel pressure from bleeding back to the tank fails, the liquid can boil more readily. Alternatively, if the trigger system (on some cars) that makes the fuel pump run when you open the door, to prime the system, fails to operate, you will get can air lock of boiled fuel which can be stubborn to move. It is not so much of a problem as it was on the old K-Jet system where it prevented the injectors from cracking open but it can still cause problems. If your local fuel “brew” contains a high proportion of Ethanol this can contribute to this issue. In the UK we currently have E95 but soon we will have E90 snuck in under our noses without us being told and that is expected to cause issues with cars barley ten years old.

OK so if that is your diagnosis how do I test for vaporisation and how do I fix it?

[Crasher]

That is what I was trying to work out, where the check valve, if fitted, is and I cannot see one which puzzles me, unless it is integral with the pump, on older systems they were on top bolted to the pump as part of the outlet. Int olde days we would clamp the feed to the engine from the pump simultaneously with turning off the ignition. Another way could be to run the car in a manner that you are sure would cause the problem and then run the fuel pump manually for about 30 seconds and then try and start it. How was the fuel pump replaced? Which fuel pump number is now fitted and what was fitted?

[ernestank]

Sorry I took so long to reply. Here is the details you requested :
Car VIN 8E63A258746
Old pump
228 233 018 005
8E0 919 051 L
New pump
A2C53171435
8E0 919 051 CJ
Audi supplied the pump and Bosch fitted it. They did however screw up the installation.

The new fuel pump unit differs from the original. The old unit had a fuel line out and a fuel return line. The new unit has three lines. A fuel line out and a fuel return line as well as an extra line. The mechanic that worked on the car fitted the new unit and did not know what the third line was for. He fitted an open piece of pipe to the extra line and let it hang loose above the right rear suspension. I filled the fuel tank on Saturday afternoon and drove to a meeting in Amberfield. While at the meeting a security guard came to inform me that fuel was leaking out of my car. I found a dam of fuel under the car. I phoned Carlo du Plessis from BCS Cencar and explained to him that the car had been at BCS Cencar and that there was a problem with the car leaking fuel. He said that they were closed and that he could not be of help. I went home and found the open pipe where the fuel was leaking from. I removed the pipe and temporarily blocked the line to stop the leak. Approximately a quarter of a tank of fuel had leaked from the open pipe. The mechanic had also broken the old unit.

2536625367

That is what I was trying to work out, where the check valve, if fitted, is and I cannot see one which puzzles me, unless it is integral with the pump, on older systems they were on top bolted to the pump as part of the outlet. Int olde days we would clamp the feed to the engine from the pump simultaneously with turning off the ignition. Another way could be to run the car in a manner that you ar sure would cause the problem and then run the fuel pump manually for about 30 seconds and then try and start it. How was the fuel pump replaced? Which fuel pump number is now fitted and what was fitted?

[Crasher]

It is partly the fault of Audi, it is clearly stated on ETKA that they should have provided the pump with part number 8E0 201 263 G which is £6.91 as is a cap to seal off the additional port required by cars with a supplementary petrol fired heater. On your car, suction jet pump 8E0 201 863 D must also be fitted to the output but that is supplied with the pump. Do you have a picture of the top of the new pump installation?

[ernestank]

It is partly the fault of Audi, it is clearly stated on ETKA that they should have provided the pump with part number 8E0 201 263 G which is £6.91 as is a cap to seal off the additional port required by cars with a supplementary petrol fired heater. On your car, suction jet pump 8E0 201 863 D must also be fitted to the output but that is supplied with the pump. Do you have a picture of the top of the new pump installation?

So if a supplier gets it wrong it is OK for the installer to "make a plan"?:confused: The person that installs the parts is ultimately responsible. My account for these repairs were R23000. at R10 to the $ $2300:zx11:. A lot of money for not fixing my car. Here are pics of new pump installed.

254032540225404

[Crasher]

The cap is there but I don't see the suction jet pump. Avoiding errors like this is one of the advantages of using a VAG specialist, they will know about stupid simple issues like this OR their parts supplier will advise them. The suction jet pump issue worries me, I need to look into it but today I was watching two Lancaster's and a Vulcan flying across Lincolnshire and **** all else was important to me.....

[ernestank]

This issue is solved. I have absolutely lost my trust with all the specialists out there! I took the car to an Audi dealer and they quoted me the equivalent of US$4000 to repair the car. The car sells for less than that!
I replaced a $50 part and it is 100%.

[micheal balbrig]

Dont leave us all in suspense !!

[ernestank]

Dont leave us all in suspense !!

After Crasher left me hanging I was NOT impressed :zx11: so I contemplated my next action.....
I did as he suggested, I took it to the real BOFFINS!!! Audi dealership!!! they basically told me that the whole top end (head etc.) needed to be replaced together with oil pump etc. etc. US$4000

I decided to drive to the store and buy a case of beer and spend some time with this problem child. Do some man stuff. Get the finger nails filled with grease and grime and the face blackened and streaked. (and perhaps save a sh!tload of money.

I got home, poured me a beer and opened the bonnet.
After opening my second beer (15 minutes) I tried starting the car and 'strues bob, the engine started and died immediately.
I removed a spark plug and found it wet with petrol. Exhaust stank of petrol.
Conclusion... engine was flooding with too much petrol. Now to get to the cause.... But first another beer.
The beer had the desired effect and I threw caution to the wind and started pulling of sensors and pipes and stuff that I thought may be the cause of the flooding.
One such pipe was the vacuum pipe connected to the fuel pressure regulator (FPR). After pulling it off I fetched another beer from the fridge and when I came back there was a strong smell of petrol in the engine bay. I stuck my nose in the engine and found that the fuel pressure regulator was leaking fuel through the vacuum pipe connector. I did not put the vacuum pipe back and started the car. Engine started immediately and purred like a kitten.
I Switched the engine off, fetched another beer, came back 15 minutes later to more fuel dripping from the FPR.
I started the car. Engine started immediately and purred like a kitten.
I removed the FPR and purchased a new one from Audi (as recommended by Crasher, use only genuine parts!)
Fitted the FPR and the car has been running PERFECTLY ever since. :approve:
I concluded that the FPR was dripping fuel into the intake manifold. This caused the engine to flood when trying to start it after driving and leaving the car for 15 minutes to an hour. When the car stood for long enough the fuel had time to evaporate and then the engine would start normally. Go figure.......
O and I DID SAVE a SH!TLOAD of money!!!:biglaugh:

[Sam]

After Crasher left me hanging I was NOT impressed :zx11:

How dare he!

Glad you got it sorted in the end and thank you for wrapping up the thread.

[A4mike]

Hi all,
I currently have the exact same problem on an Audi A4 2007 1.9 TDI could this also be the issue on a diesel model?
Many thanks in advance
Mike

[Crasher]

After Crasher left me hanging I was NOT impressed :zx11: so I contemplated my next action.....

What do you mean left you hanging? And I was right......

[A4mike]

Hi Crasher,

I have the same problem with my Audi A4 1.9 diesel 2007 model, could this be the issue in a diesel engine, is this component in a diesel? Again not throwing any codes with vcds, i have had battery checked, glow plugs, fuel filter, fuel pump, crank sensor temp sensor, one way valve in fuel line to stop fuel running back, injectors checked one came back new so must have been faulty, the list goes on however he has never mentioned looking in to fuel pressure regulator, is this because there isn't one on a diesel?
Many thanks in advance,
Mike