Rattle under load when engine is hot

[DubSteve]

[jmystaki]

Hi sydVR6

VAG Showing no codes.

I have been running 98 octane fuel, with an additional octane booster... I think this has a major improvement, but still not enough...

Injectors and head have been cleaned with Petroject machine. I also decarbed the head a few times myself..

I have been using all sorts of injector cleaners products....

no luck.

I cannot see any clear way to tell how effective the knock sensor is with VAGCOM.... I guess it is working as i usually have reduced performance when the engine is really hot...(retarded timing)...

[Bug_racer]

how about posting some logs ?

Injector duty cycle and lambda values as well as ignition timing and intake air temp ?

[h100vw]

How tight is the bolt on the knock sensor? I forget the setting but it's only like 10-15 lbs.

Gavin

[jmystaki]

Hi Bugracer - please check out post 42 of this thread... I have attached logs there.

If you need more data I would be happy to log some more... just let me know what you need.

H100vw - yep, the Knock Sensor is set correctly at 15 foot pounds of torque.

Cheers

[Bug_racer]

Hi Bugracer - please check out post 42 of this thread... I have attached logs there.

Ive gone through the logs and they arent very helpful .

there is only one time where you actually go above 2000rpm , and the intervals are like almost 5 seconds apart !

When you log an old car you can only do 1 channel at a time so you can keep the frame rate above 1.1-1.2 . Do those same channels again , this time logging 1 at a time !

(why do I get the feeling no-one else knows how to read logs???)

[sydVR6]

Well, I'm going to throw something new into the mix here.

A non-functioning EGR valve could be causing your ping problem. You could check that the valve opens properly and the ports under the valve are clear.

Bit of an explanation here;

http://autorepair.about.com/od/gloss..._egr-valve.htm

I don't think this has been suggested yet and I've seen blocked EGR valves cause similar problems on a few Jap cars, so worth maybe looking at...

[Bug_racer]

MK3 doesnt have EGR valve as far as I know .

Well, I'm going to throw something new into the mix here.

A non-functioning EGR valve could be causing your ping problem. You could check that the valve opens properly and the ports under the valve are clear.

Bit of an explanation here;

http://autorepair.about.com/od/gloss..._egr-valve.htm

I don't think this has been suggested yet and I've seen blocked EGR valves cause similar problems on a few Jap cars, so worth maybe looking at...

[sydVR6]

I know the VR6 does. I'm pretty sure the 2.0 does (without the Bentley manual in front of me) but could be wrong.

GAP stocks them for the 8v:

http://www.germanautoparts.com/Volks...f/Engine/317/1

[Bug_racer]

Show us a picture , Ive never seen one on a Australian VR6

US cars are different to ours dont forget

I know the VR6 does. I'm pretty sure the 2.0 does (without the Bentley manual in front of me) but could be wrong.

GAP stocks them for the 8v:

http://www.germanautoparts.com/Volks...f/Engine/317/1