crankshaft sensor

[david4853]

hi there does anyone know if the crankshaft sensor on a A4 quattro is a dificult job to do,95 model??

[Crasher]

Engine type?

[david4853]

hi,the engine is a 2.6v6 thats all i know!

[Crasher]

That is an ABC engine and the engine speed sensor (G28, grey) part number 078 905 381 A (£134.89) but there is also the ignition timing sensor (G4, black) in the same bracket, part number 078 905 375 (£86.09). Changing the speed sensor G28 requires special tools 3242 (to lock the crank in position, the same tool used when changing the timing belt) and tool 3308, to check the position of the bracket. Do you know which sensor you need to change?

[Jonnovision]

Hi Crasher - Do you know if the 2.0E Audi Coupe 1995 8v has the above sensors? As per the forum I have a intermitant start problem and am trying to diagnose what could be causing it. Looking up the registration on Eurocar Parts it tells me that my engine type is ABK. Would you know what the part numbers would be?? My mechanic said he thinks it could be the crankshaft sensor, but does not know where to locate it specifically on my car.

On the dianostic check the speedo sensor was deemed to be faulty - and I think the mechanic said this was the only sensor in/around where he might expect to find a sensor that may also manage the crankshaft sensor "stuff" - so we are using a process of illimination to try and work out why the car intermitantly doesnt start. He is an honest mechanic, but not an Audi specialist (although by the end of this he may well be!). I fear the last owner steam cleaned the engine - so far I have had this speedo sensor, two temp sensors and the fan switch fail, within the last 2 months... Any help appreciated.

Many thanks,

Jonno

[Crasher]

PM me the reg number.

[Jonnovision]

Thanks Crasher - I have PM'd you the number originally assigned to the Vehicle.

Thank you!

[Jonnovision]

Hi Crasher - also - ref my other post on the intermittant start issue (when subsequently doing some wider digging I found this Crankshaft sensor thread) do you know if a faulty Speedo sensor on a 2.0E 8v 80 Coupe would/could cause problematic starting? This sensor came up as faulty on the diagnostics so its being replaced... I found another post which referred to a similar issue, but was on a later Audi A4. I thought that the speedo sensor would do just that, send the signal to the speedo dial as well, but does a faulty signal impact the ECU operation?

Jonno

[Crasher]

The ABK only has a distributor hall sender, if the code read is carried out with the engine not running, this code will come up anyway.

“00513 Engine speed sender-G28 No signal”

Notes on fault code 00513:

Engine control unit receives engine speed information from Hall sender in ignition distributor.
Hall sender -G40 is monitored instead of engine speed sender -G28.
Fault code can be ignored with ignition on and engine not running.
Observe fault code with ignition on following unsuccessful attempted starting (engine does not start).

[Jonnovision]

Hi Crasher - thanks for this - So I had the garage change the speedo sensor - and interestingly the non starting has stopped. However, my speedo still intermittantly dies - could this be an earth issue?

Thats interesting actually - what does the distributor hall sensor do? I did take off the dissy cap and check the condition over the Christmas period (everything looked fine). Could I have unwittingly knocked something?

[Crasher]

The hall sender tells the ECU where the engine is to trigger fuel delevery and sparks.

[Jonnovision]

Hi Crasher - Thanks for this - where is it located/what does it look like on the engine?

[Crasher]

It is inside the distributor.

[Jonnovision]

Hi Crasher - I had the non start problem again tonight, even though it hasnt played up in 3 weeks or so. Anyhow - after turning the engine over a few times and it not firing I raised the bonnet and smelt for fuel (couldnt smell a thing), as I guess I was trying to understand if it could be that the signal wasnt going from the hall sender (or somewhere else) and therefore I guess the ECU would not start the fuel pump etc.

So - I remember you mentioned the distributor, and also that this problem started roughly around the time that I took off the distributor cap to check the rotor arm etc at Christmas.

There is a connector or plug on the side of the distributor, so I gave that a wiggle, and tried starting the car - it fired up straight away!

So - I think it could therefore be this - is this the connector for which the Hall sender sends its signal? Doe anyone know what this plug does??

Additionally, whats the best remedy here - do I spray the connector with something like damp start or lithium grease? OR should I change the plug or change the distributor? Not sure how to approach this really.

Let me know what you'd advise?? (and anyone else can too!)

Thanks all

Jonno

[Crasher]

The connector you wiggled is the hall sender. This says that the problem could be the wiring to the sensor from the plug which is not easily reapaired, the plug contacts or the wiring from the car to the plug and its contacts. If the cars wiring and plug are OK, then you will need to replace the sensor. This is not available from VAG as a spare part but is available from Bosch but I am not 100% sure of the part number but I think it is 1 237 031 296.

[Jonnovision]

Thanks Crasher - I'll inspect it tomorrow when there is daylight. This is the 4th sensor to go in as many months now - I get the feeling the previous owner must have steamcleaned the engine bay and not given the car a good run to dry everything out. I expect (or hope) it is a case of corroded contacts, which I'll try to clean up.

I will have a word with my mechanic reference the Bosch sensor and see if he can see what it would cost to have it replaced - I think there used to be a Bosch centre in Bournemouth near where I live - I'll check it out, or perhaps go there and ask them directly.

Thanks once again for the advice!

Jonno