Knock sensor?! What the heck is that!?

[bigfella_V5]

16523 - Oxygen (Lambda) Sensor B1 S2: Response too Slow
P0139 - 35-10 - - - Intermittent
16717 - Knock Sensor 2 (G66): Signal too High
P0333 - 35-10 - - - Intermittent
16497 - Intake Air Temp. Sensor (G42): Signal too High
P0113 - 35-10 - - - Intermittent

Couple of questions, which Lambda probe is this that i need to replace?

The intake fault I take is a faulty MAF?

And best of all, what the heck is a "knock sensor"?

Cheers for your help, come and collect your pint.

 

[Big_A_Cupra20vt]

hey i had that fault to all i found out about it was something to do with strange engine noise i think like a missfire or something i think mine was due to my oil pump dying and nearly killing my biza.

 

[bigfella_V5]

Strange as mine seems to sound fine and runs fine too.

Has your fault gone away now?

 

[Big_A_Cupra20vt]

yeah mine does now but i still have that fault well i did until i reset all faults i havnt checked it since but im assuming it will have gone now, or possibly your sensor is fooked

 

[bigfella_V5]

It sounds like an internal engine sensor, wonder where they are located so I could swap it.

 

[Big_A_Cupra20vt]

that i dont know i could find hardly anything out about that code.

 

[Fen]

A knock sensor detects knock. Knock otherwise known as pinking or pre-ignition is when the fuel mixture detonates before the spark plug fires. It can completely destroy the engine if it's bad enough because it is effectively pushing the piston downward when ideally it should still be going upward. It also causes more heat in the cylinder than is healthy.

Avoiding it basically means running a richer mixture and that hits economy and performance so manufacturers set the engine up close to the limits and use sensors to dynamially pick up mild knock and adjust to compensate. Not necessarily anything to worry about is my guess.

Cheap/poor fuel is also a cause of knock, as is too much boost on turbocharged cars. Don't use supermarket 95 RON petrol if you have been.

 

[bigfella_V5]

Fen, thanks for taking to time to write that up - it now makes sense.

I don't think there is a fault as such - possibly with the sensor itself.

How the hell did you know that though!?

 

[Fen]

Too much time spent reading about cars - and I guess I picked up a lot fitting standalone engine management to my 944.

 

[bigfella_V5]

Do you know what the difference is between the 2.3 v5 and the 1.8 20v Turbo?

If the bore is different or if the stroke is different.

If the bore is the same but stroke is longer surely its possible to turbo the 2.3 v5?

 

[Fen]

Sorry I don't know that one, generic questions or detail on Porsches, some BMW, RS6 etc. only.

I don't really see the logic either to be honest - or do you mean you could use 1.8T pistons in the 2.3 to reduce the compression ratio? There would be a lot more to it than that though - manifolds would be the most obvious thing that isn't available off the shelf.

 

[bigfella_V5]

Are the manifolds very different then? Not the same block, bore piston size or stroke?

 

[Fen]

Well one's a 4 cylinder and one's a 5 cylinder.

 

[GrayT]

If the bore is the same but stroke is longer surely its possible to turbo the 2.3 v5?

Check out the second link in post 1 of this thread: http://www.seatcupra.net/forums/showthread.php?t=96800&highlight=v5+turbo

It has been done on a Bora V5. Interesting pics although unfortunately the site is in Swedish. As for cost, you will need very, very deep pockets!