sinister engine noise, im quite worried.

[superkarl]

What blocks should I be looking at? Block 20? 26?

 

[superkarl]

Hello guys I could really do with some advice.
I want to be sure whether it is knock or not and know whats going on inside.
Last night I had multiple misfire on all cylinders and a code on cylinder 3(the one that was popping up) they cleared and never returned after a drive so I assumed it was due to me pulling them out and checking plugs etc.

I really need to know what I should be monitoring in vcds, and what values mean what, ie, tell tale signs of knock, if it is that. What should i look for?
Knock sensors are doing something i know that, cf's didn't go very high at all. But then, i was reluctant to do a wot run to red line.

Any advice is massively appreciated, I'd love to prove its not detonation. Then i can worry a little less. I would have thought after fitting my catch can this would be massively reduced

 

[superkarl]

Hello guys I could really do with some advice.
I want to be sure whether it is knock or not and know whats going on inside.
Last night I had multiple misfire on all cylinders and a code on cylinder 3(the one that was popping up) they cleared and never returned after a drive so I assumed it was due to me pulling them out and checking plugs etc.

I really need to know what I should be monitoring in vcds, and what values mean what, ie, tell tale signs of knock, if it is that. What should i look for?
Knock sensors are doing something i know that, cf's didn't go very high at all. But then, i was reluctant to do a wot run to red line.

Any advice is massively appreciated, I'd love to prove its not detonation. Then i can worry a little less. I would have thought after fitting my catch can this would be massively reduced

 

[s3dave]

Block 20 will give you an idea of knock

 

[aragorn]

As above Block 20 shows how much the ECU is retarding the timing for each cylinder as a result of detecting knock on it.

 

[superkarl]

So if I have very high values then it tells me there is knock? What sort of figures should I see or not see?
And thankyou

 

[Welly]

So if I have very high values then it tells me there is knock? What sort of figures should I see or not see?
And thankyou

The higher figure, the bigger the knock.

The general rule of thumb is up to 6 Correction Factor (CF) is acceptable.

So, up to and including 6 is within tolerance.

 

[Welly]

Example of a block 020 log:

Group C:	'020			
	
TIME				
STAMP	 CF	 CF	 CF	 CF
	0	0	0	0
	0	0	0	0
	0	0	0	0
	0	0	0	0
	0	0	0	0
	0	0	0	0
	0	0	0	0
	0	0	0	0.8
	0	0	0	2.3
	0	0	0	2.3
	0	0.8	0	2.3
	3	0.8	0	1.5
	3	0.8	0	0
	0	0	0	0
	0	0	0	0
	0	0	0	0

 

[Alex C]

what does CF stand for?

 

[Welly]

what does CF stand for?

Correction Factor

:thumbsup:

 

[superkarl]

I take it this should be done at wot in 3rd to redline, niiiiice. I don't remember seeing very high values at all when doin the odd wot Sprint last night. I shall try again. Is there anythin else I could monitor?
Cheers welly.

 

[Alex C]

lol, duh. Sorry, thats laziness on my part, didnt bother scrolling up

 

[finesse]

Any oil in the intercooler pipes? Oil vapours = high CF

 

[Welly]

I take it this should be done at wot in 3rd to redline, niiiiice. I don't remember seeing very high values at all when doin the odd wot Sprint last night. I shall try again. Is there anythin else I could monitor?
Cheers welly.

Depends what you want to find out bud. There are so many things that are useful.

Block 011 - Ignition advance and inlet air temperature.

Block 115 - Requested vs actual boost.

Block 118 - Actual boost and N75 duty cycle.

Block 002 - Mass airflow and injector on time.

Block 001 - Lambda fuelling adjust percentage live.

Block 020 - Idle Stabilisation (knock).

Block 032 - Short and long term fuel trims (Don't reset fault codes or else these will both be 0.0%)

Block 031 - Air-Fuel ratio Specified vs Actual (Wideband ECUs only)

There are so many that can be done, but those are the ones I use most often.

All logs (With the exception of 032) are a third gear low rev to redline job.

 

[Welly]

Any oil in the intercooler pipes? Oil vapours = high CF

Yarp, common on older cars now with dying turbos....

 

[superkarl]

I basically want to look for evidence of knock, because that's what we think it could be.
So basically, if I don't have cf in excess of 6 there is no knock.
I've only ever had a small amount if oil in boost pipes, and thats before catch can.
I'm sure il get to the bottom of it, just got to start eliminating things.

 

[finesse]

Tuffty and Welly pointed out to me that cf of 0 is ideal......

 

[SanityClause]

I had that kind of sound once on my A6, turned out to be the cat disintegrating, the noice was ceramic parts of it inside the exhaust.

 

[superkarl]

Hmmm, it does sound like its right infront of me though

 

[finesse]

But ze cat is below the driver seat area?

 

[superkarl]

Possible, and sounds like that kind of sound.

 

[finesse]

you can test the cat health on vagcom, will post back with instruction

 

[lukejenks]

thos sounds quite similar to what my car used to and just started again yesterday. when I put my foot down and the Turbo kicks in you get a click click click but quite fast and Loud. What causes it on mine is the engine rocking back causing a pipe to catch on the propshaft. Have a look towards that area. could be similar problem. but everything with my car is a mystery!

 

[finesse]

Block 046

EGT must be greater that 320 degrees

Field 3 must be below 0.50

Field 4 must say B1 ok

 

[superkarl]

Thanks finesse most appreciated. Hopefully get round to logging tonight. Will have to wait till the weekend to give the engine a good seeing to. Good thing im not using it recently.