Help Needed Interpereting Fault Codes

[dirtbiker]

Hi all,

Bit of background- I had a slight blow in the flexible section in the downpipe which got quite a bit worse (sometimes causing the engine to missfire until it was warm) so I bought a new downpipe and cat and fitted them, hoping this would solve the problem. They seem to fit fine and be sealed when the engine's running. I've obviously put the lamda sensor back in to the new cat section and didn't use exhaust paste while fitting them.

Got a new problem with my Leon 1.6s (16v - AZD engine) now - it seems to drive fine as long as the revs are kept below about 3k but going any higher than that results in a buzzing noise from the engine compartment and a major loss of power. I've not noticed any loss of coolant but there was a lot of steam from the exhaust when I started it up this morning. There's a little bit of "mayo" on the underside of the oil cap but it's not been driven much recently and not done any long trips.

I've got a couple of warning lights on in the instrument cluster:

Am I right in thinking this is looking like a head gasket failure?

Using my fault code reader (http://www.gendan.co.uk/product_GDVAG.html) the following codes seem to be logged:

• 16684 Random Misfire Any Cylinder or Random/Multiple Cylinder Misfire P0300
• 16685 Cylinder 1 misfire detected P0301
• 16687 Cylinder 4 misfire detected P0303
• 16688 Cylinder 4 Misfire detected
• 17961 Barometric/Manifold Pressure Signals Impausible Correlation p1553
• 16708 Knock regulation Malfunction P0324
• 17912 Intake Ais System Bypass Air determined or Intake Air system leak detected p1504

and under ATS dtc02

• 01314 control module in instrement panel on Comfort CAN (J285) twice

Here's the general thread on the problem: http://www.seatcupra.net/forums/showthread.php?t=202070

Can anyone shed some light on what the fault codes mean?

 

[dirtbiker]

Well, a bit of Googling would suggest that the first four fault codes are due to spark plugs or coilpack problems so I'm going to replace the plugs (although it seems they were done about 10k ago) and try swapping the coil packs around to see if one (or more, I guess) of them have failed.

Not sure what to make of the other codes though? Any thoughts appreciated.

 

[m0rk]

I'd be checking your wiring....

 

[dirtbiker]

Aye, I think that's a good plan but unfortunately the car's in Southampton and I'm in Nottingham so I'm having to work on it remotely via my Dad, a somewhat tortuous process! Will get him to take a look under the engine cover tomorrow and see if anything's obviously wrong, otherwise I'm heading home next weekend so will work on it then.

Cheers m0rk

 

[dirtbiker]

Right, so my Dad says there's no obvious problems with the wiring in the engine bay so I've ordered four new coils from GSF and will be pulling the spark plugs out, checking the gap and replacing any that look like they need it followed by fitting the new coils on Saturday.

My Dad also mentioned the fault code reader wouldn't let him delete the logged codes for some reason, does anyone know why this might be? I'm going to disconnect the battery while working on the car so this will presumably reset the ECU and may allow the codes to be cleared?

I'm still a bit concerned about the other fault codes but I've read that a coilpack failure can cause other sensors to record faults so perhaps it's all down to the key problem. I'm assuming that running the car with a leaking exhaust probably led it to be a bit unhappy too?

Any thoughts appreciated and thanks for the help so far!

 

[m0rk]

Chris, I don't live far from scummerland these days - I can run over there with vag-com?

 

[dirtbiker]

I may just take you up on that, will see how I get on with replacing the coilpacks and if I'm still having troubles then that'd be much appreciated! Seem to have mislaid your number so will drop you a PM.

Thanks!

 

[dirtbiker]

Right, so I'm home now and had a chance to take a look at the car this afternoon.

Cleared all the fault codes and fitted four new coil packs - started the engine up and it's running exactly as before, very rough at idle and with a rattling/buzzing noise from the engine bay throughout the rev range.

Initially the only fault codes that were recorded are:

17961 - Barometric/Manifold Pressure Signals Implausible Correlation p1553

01314 - Comes up whenever the ECU logs a fault for the engine, I believe.

After taking it for a short (4 mile) drive the 17961 code has disappeared and is replaced with:

16407 - Bank 2: Camshaft B (Exhaust): Position Actuator Malfunction

01314 is logged as before.

This is very similar to this thread: http://www.seatcupra.net/forums/showthread.php?t=188171

It seems that the coilpacks weren't at fault (which is good as I can take them back!) but I'm currently thinking that it's possible that the exhaust cambelt has come loose? It's too dark now for me to take a look but that would probably explain the rattling noise and running problems?

As ever, any thoughts appreciated!