What can cause a running engine to stop without warning signs?

[EvenM]

Hello

I cant figure out whats wrong with my s2

The car starts and runs normal for 15-20 min, and then suddenly the engine just stops/ dies without any warning signs. And it wont start again. If I wait a day or two, it starts again, and dies after 20 min ca. Its a 93 model aby with rs2 spec engine and ecu.

What can cause this?

Im guessing some Electric problem ?

I have tried to change crank and speed sensor without any improvement.

Thanks for any advice

[hunker7]

Hello

I cant figure out whats wrong with my s2

The car starts and runs normal for 15-20 min, and then suddenly the engine just stops/ dies without any warning signs. And it wont start again. If I wait a day or two, it starts again, and dies after 20 min ca. Its a 93 model aby with rs2 spec engine and ecu.

What can cause this?

Im guessing some Electric problem ?

I have tried to change crank and speed sensor without any improvement.

Thanks for any advice

Thermo fuses next to the ECU. Replaces all of them with normal fuses not sure what values. Sure someone will know here.

[Lago Blue]

Only you can prevent basic Audi-illiteracy...

Hey fellow fancy car owner,

Your car may already be trying to tell you what's wrong.

It's likely already sent you a coded message, if you would but read it/them.

How do you stop an Audi owner from guessing what's wrong with his car? Remind him gently that the owner's & maintenance manuals are required reading (see the engine trouble-shooting section); and that the forums wonderful archive is entirely searchable? Yah, maybe, try it, see what happens.

http://www.s2forum.com/forum/showthread.php?t=79795&highlight=diagnostic+codes

[DEREKCO]

Cuts out

Excellent advice well said

[EvenM]

Thanks, the car does not give me any fault codes that is about running issue. Been checking vagcom and vwtool program several times. Only fault on display is about the g52, that should not cause the engine to die

Been googling and Reading plenty of threads here and elsewhere without any luck :/ So Im kind of lost

[EvenM]

Thermo fuses next to the ECU. Replaces all of them with normal fuses not sure what values. Sure someone will know here.

Okey, thanks, will give it a go

[John.]

Could the ignition switch be playing up?

[UrS4boy]

The car starts and runs normal for 15-20 min, and then suddenly the engine just stops/ dies without any warning signs. And it wont start again. If I wait a day or two, it starts again, and dies after 20 min ca. Its a 93 model aby with rs2 spec engine and ecu.

Hunker7's (Janis's) suggestion was a good one to try. Those old thermal fuses in an UrS4 AAN can fail open and shut down the ECU. Not sure if there are any such fuses with the S2/RS2 though. Have a look.

The issue is obviously heat/current related. Current is running through an electrical component of the ECU and/or ignition system and at a certain point, that component is temporarily failing, often without throwing a code (which would be helpful).

In addition to the thermal fuses, another component that will fail like that is the G40 Cam sensor (often without the 2113 blink code). A temporary fix to get you going again in that case is to pour cold (preferably ice cold) water down the back of the top of the cam cover to cool down the G40 cam sensor. Often that is enough to get you going again, at least for a few minutes. Ultimately the cam sensor has to be replaced. This can be done without a full cam belt job.

G40 Cam sensor info:

http://forums.quattroworld.com/s4s6/msgs/22580.phtml

G40 Replacement DIY:

https://get.google.com/albumarchive/104138090013789212848/album/AF1QipM-DERi6PobPurS7dcyCctKVCCAU9D3jsKr2ZWq?source=pwa

[EvenM]

Thanks, I have read the information about the g40, but if I remember correctly from the information (maybe it was from you?) it can not make the engine stop if failing while driving, or am I wrong ?

on your Thoughts of this being a electric /heat related problem, and without the ecu giving any fault codes I need to ask you guys for good guesses and hopefully I will find the culprit

Hunker7's (Janis's) suggestion was a good one to try. Those old thermal fuses in an UrS4 AAN can fail open and shut down the ECU. Not sure if there are any such fuses with the S2/RS2 though. Have a look.

The issue is obviously heat/current related. Current is running through an electrical component of the ECU and/or ignition system and at a certain point, that component is temporarily failing, often without throwing a code (which would be helpful).

In addition to the thermal fuses, another component that will fail like that is the G40 Cam sensor (often without the 2113 blink code). A temporary fix to get you going again in that case is to pour cold (preferably ice cold) water down the back of the top of the cam cover to cool down the G40 cam sensor. Often that is enough to get you going again, at least for a few minutes. Ultimately the cam sensor has to be replaced. This can be done without a full cam belt job.

G40 Cam sensor info:

http://forums.quattroworld.com/s4s6/msgs/22580.phtml

G40 Replacement DIY:

https://get.google.com/albumarchive/104138090013789212848/album/AF1QipM-DERi6PobPurS7dcyCctKVCCAU9D3jsKr2ZWq?source=pwa

[UrS4boy]

Thanks, I have read the information about the g40, but if I remember correctly from the information (maybe it was from you?) it can not make the engine stop if failing while driving, or am I wrong ?

Read what I wrote about the G40 again. It shouldn't stop a running car if it fails *BUT* there are documented cases where it did and it drove the owner mad until they changed the G40.

[bluequattro]

I'd go for thermal fuses.
I had a urs4 dump me on a fast dual carriageway due to these.
Have you checked for spark when it's done it's dying trick

[Ryss]

When it will not start check the basics.
Spark, fuel etc. Could be blocked fuel tank breather, dicky fuel pump (brushes worn) etc.

[EvenM]

Okey, my bad That could probably be the problem in this case Will try to change those fuses first (if they are there in the s2), if that does not work, I will try to change the g-40 I think



QUOTE=UrS4boy;940381]Read what I wrote about the G40 again. It shouldn't stop a running car if it fails *BUT* there are documented cases where it did and it drove the owner mad until they changed the G40.

[/QUOTE]

[EvenM]

Will try change them (they are in the s2 aswell as the s4?)

When it stops and are dead I have no spark , if that is what you ment ?

I'd go for thermal fuses.
I had a urs4 dump me on a fast dual carriageway due to these.
Have you checked for spark when it's done it's dying trick

[vag_noob]

maybe check for damp carpet around the ECU while you are in there