Starting problems NOOOOOO!!!!

townlondon

Member
Hi A2ers,

I hope all is well with you.

My very reliable and trusted, Audi A2 is starting to make me nervous...

I made a few trips today only about 60 miles with many stop offs and as usual in London lots of traffic. I then made a few brief stops (15 mins) and the car would not start again. I turned the key and there was no power in the accelerator, the revs indicator was not moving, I could just hear the starter motor turning over. A few times there was a chugging sound, juddering and shaking and then nothing.

I prayed waited and prayed some more, then eventually it would start up again. Done this 4 times during journey. Once there was a juddering run on upon starting the car had momentum and then nothing, no power ground to a halt.. Just near a traffic light...

Prayed, waited..... prayed, waited......generous offers of help, waited some more and then bingo started again.

This only happened once a few years ago. Scared to drive it now.

I have had it over 8 years on the same battery could that be the problem?

Taking it to the mechanic very soon, just wondered if you had any ideas.

P.S Sod's law I opened my big mouth to tell a person who was admiring my car "it has never let me down" grrrrrrr

P.P.S Prayer works
 
It would be a great help in knowing what engine you have ie 1.4 petrol /diesel 1.6 petrol ?
If it re starts when it's cooled down it could be a crank shaft sensor starting to fail. Cheers Mike
 
I would start by replacing the battery, 8 years old it's probably near death. You probably need a new one anyway. Then try that for a bit. If you still have problems come back here and give us more details

What kind of engine (petrol 1.4/1.6? diesel?)
Does the starter turn slowly? or does the starter turn at normal speed? Does the engine fail to start, or does it start and then die later?
etc
 
Hi thanks for replies. Much appreciated!

it's an Audi A2 FSI SPORT Petrol 2002. What's the best battery to buy?

Starter seems to turn over normally...just no power.....engine fails to start, but will after 6 or so attempts with long pauses in between attempts. I have it booked into the mechanic in the morning, hope it will make it there....

It generally starts first time from cold, but then after going for a while will fail to start after a short stop off. but has died soon after starting and going a short distance.

My gut tells me it's the battery, will update you when I get it back, hopefully.

Any other ideas appreciated.....
 
Thank you, I'm taking it into the mechanic in the morning. Will update on the findings. Hope it's not too expensive... What's the best battery for Audi A2?
 
Thank you, I'm taking it into the mechanic in the morning. Will update on the findings. Hope it's not too expensive... What's the best battery for Audi A2?

For the TDI, it'd be the Varta Silver type 110 ... a nice upgrade from the original battery in terms of capacity etc. The Bosch S5 is also popular on the forum. But I don't know the correct batteries for petrol cars (usually diesels use a much bigger battery than petrol cars).

The batteries in the A2 last a long time - I think because they are protected from the heat and elements.


-- Edit:
Done a bit of searching,and in this thread the type 096 is recommended:
http://www.a2oc.net/forum/showthread.php?22013-Which-Battery-FSI-1-6-Petrol
I have no experience there and can't tell you if that's correct or not.

-- Edit 2:
Also seen the type 096 recommended in other threads, so probably OK.
 
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Hi Mike, I took my car to my mechanic. He checked the battery and that is all good. He suggested a coolant temperature sensor ( as it does not alert me to low coolant anymore) and a crankshaft sensor to solve the warm starting problem. However, he did not check the car with the scan machine. He plugged a machine into the battery and showed me that was good. Just concerned I'm buying 2 sensors and it may not be the actual fault. What do you suggest? Should he have done a scan first?
 
Hi Mike, I took my car to my mechanic. He checked the battery and that is all good. He suggested a coolant temperature sensor ( as it does not alert me to low coolant anymore) and a crankshaft sensor to solve the warm starting problem. However, he did not check the car with the scan machine. He plugged a machine into the battery and showed me that was good. Just concerned I'm buying 2 sensors and it may not be the actual fault. What do you suggest? Should he have done a scan first?

The coolant temperature sensor is worth replacing but it has no connection to the low coolant sensor, they are very different.

The coolant temperature sensors are known to cause problems and if there is any doubt they are worth replacing, they will be cheaper than other parts that may be giving you similar problems.

A VCDS scan might help, you can see both temperature readings from the sensor (one controls the temperature gauge and the other gives the ecu the information about the engine temperature so that it knows what fuel mixture to use. When this part of it goes the engine sometimes thinks it is hot when it is cold, or cold when it is hot and so the car becomes difficult to start when hot, or when cold.

Steve B
 
The coolant temperature sensor is worth replacing but it has no connection to the low coolant sensor, they are very different.

The coolant temperature sensors are known to cause problems and if there is any doubt they are worth replacing, they will be cheaper than other parts that may be giving you similar problems.

A VCDS scan might help, you can see both temperature readings from the sensor (one controls the temperature gauge and the other gives the ecu the information about the engine temperature so that it knows what fuel mixture to use. When this part of it goes the engine sometimes thinks it is hot when it is cold, or cold when it is hot and so the car becomes difficult to start when hot, or when cold.

Steve B


Hi Steve,

I have asked my mechanic to do a full scan before I invest in two sensors that I may not not need as they come to a total of over £130, genuine Audi parts.

I will keep you updated.

Car is working, starts fine cold. Just can't make too many stop offs, A- B right now. Thank you for the info.
 
Hi Steve,

I have asked my mechanic to do a full scan before I invest in two sensors that I may not not need as they come to a total of over £130, genuine Audi parts.

I will keep you updated.

Car is working, starts fine cold. Just can't make too many stop offs, A- B right now. Thank you for the info.

Hi
Yes the scan is essential before buying parts.
But you need the correct scan and it to be done by someone who knows Audis well.
But there is no need to replace two temperature senders. The only one that could possibly affect starting is the one that has four pins, usually green plastic on it.

Even at a dealer they are less than £50 and around a tenner on eBay.
Other coolant senders just control the fan or the coolant level and have no effect on starting.

Steve B
 
Hi, I had a scan done pictures attached.

Fault code P1031 " induction pipe doors.valve target value not attained"

And some cylinder misfire fault codes that my mechanic said was not the case, as the engine seems to be working fine.

No evidence in the scan of the sensors needed, crankshaft and coolant temperature.

The engine warning light came on soon after I got the car (8 years ago) it was investigated by my mechanic but nothing was found to be causing the problem.

Any suggestions on what I should do next? Thank you.

image.jpg image.jpg
 
Hi
Yes the scan is essential before buying parts.
But you need the correct scan and it to be done by someone who knows Audis well.
But there is no need to replace two temperature senders. The only one that could possibly affect starting is the one that has four pins, usually green plastic on it.

Even at a dealer they are less than £50 and around a tenner on eBay.
Other coolant senders just control the fan or the coolant level and have no effect on starting.

Steve B

Hi Steve,

What's the name of the sensor that has four pins?? Is it the crankshaft sensor?? That's £100 from my local Audi dealer. Are there some parts where you can use non audi parts?? Thanks.
 
Some info on the P1031 fault code - http://wiki.ross-tech.com/wiki/index.php/17439/P1031/004145

Assuming all the ignition related (coils, plugs etc) are ok, random misfires can be related to a faulty knock sensor.

Temp sensors can give false readings but not log fault codes so its useful to monitor the temp rise from cold and check its giving sensible readings. Not sure about petrol engine but on TDis, fuel temp sensor faults can cause over-fuelling problems.

In the early stages of failure, crankshaft sensors can cause the engine to stop when warm without logging fault codes.

Cheers Spike
 
Hi, thanks, does this have to be a genuine Audi part or can I get a cheaper alternative? Does the coolant dual sender solve the warm starting issues? Should I buy this sensor to start with?

Thank you.

Since these senders are known to be unreliable and sometimes do affect starting (due to invalid signals making the mixture too rich / too lean) they are worth replacing if you have starting problems. You can buy cheap ones on eBay but one of the ones I bought on eBay was not working, I was given a replacement without hassle, so it is an option, but I prefer the OEM parts for things like this.

Steve B
 
The coolant temperature sensors are known to cause problems and if there is any doubt they are worth replacing, they will be cheaper than other parts that may be giving you similar problems.

A VCDS scan might help, you can see both temperature readings from the sensor (one controls the temperature gauge and the other gives the ecu the information about the engine temperature so that it knows what fuel mixture to use. When this part of it goes the engine sometimes thinks it is hot when it is cold, or cold when it is hot and so the car becomes difficult to start when hot, or when cold.

Steve B

I definitely agree with this point. I had this very thing happen on my MK3 1996 Polo. The temperature sensor probe on these has two circuits - one fed the dashboard temperature gauge and worked fine but the other circuit which fed the ecu partially failed and fed the wrong (low) temperature to the ecu. So, even when the car was warm the ecu was making the injectors fuel the car as if it was cold when in reality it was up to normal temperature. This meant the car was difficult to start when warm and would frequently stall when doing slow manouveres. It also eventually ruined the lamda probe (over rich mixture). I didn't originally spot the fault as I was using the free version of VAG COM which didn't have legend labels for the various parameters.
 
Plan of action

1.Check all ignition related parts
2.Fit new coolant temperature sender
3.Fix P1031 fault code

My coils, spark plugs and filter are all non audi parts shall I change these now to genuine or wait until needed??

Will keep you updated.

I will buy the other suggested sensor (crankshaft) if this one doesn't solve my hot starting issue.

Have I missed anything?
 
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