Pinking 8v

[Dipesh]

Hi all,

I'm a bit new to this, i've had a mk2 before, then went for something modern, now i'm back for some more!

Anyway, my mk2 is pinking under heavy load. The timings been set at 6 deg @ 2200rpm etc.. so thats spot on but still pinks like crazy even with optimax!

What can i do to fix this?

I've noticed its not so bad with the blue temp sender off but when its back on, its back again!

Has the C/O mixture got anything to do with this?

Any help would be great!

Thanks

Dipesh

[golfmk2boy]

Hi Mate,

I had the same problem with my previous 8v digifant engine, which I have now sold to someone who wanted the head.  Just fitting new engine right now...

I could not correct the problem which I believe may have been down to blown head gasket, as I was losing alot of water, and there were no leaks anywhere that I could find.

At first I got the motor tuned and it cleared it for about 1 day.... then it started up again.  I replaced the dizzy, as the cap was knackered, then got it retuned again, this time the timing was far better however the pinking came back again.

The guy who tuned it thought it might be an issue with a dodgy cylinder, or something mechanical.

What I would do is get the motor tuned if you can, should only cost about 30 squid.... or even better, try tuning it yourself.  Within the Mk2 maintainence and info is a guide to tuning, however I have not tried this yet, as it looks quite tricky (more like my brain cant be bothered, you know how it is).

Maybe try some redex, to flush the engine out, and get rid of any crap which may cause pre-ignition, which is basically what causes pinking.

Hope this helps anyway.... Get it tuned, see if it stays tuned and hey presto.... otherwise it may cost abit more.

 

[Organisys]

maybe the knock sensor has had it?

[Dipesh]

maybe the knock sensor has had it?

I've got to try this tomorrow, fingers crossed!

[Thom89]

Another couple of possibilities.. cylinder head may have been skimmed too many times, or too much, taking the C/R right up
Carbon build up on valve faces, and /or combustion chambers, causing detonation, also check that there is not an air lock in the cylinder head, causing top end overheating
All the above are very common problems on all types of engine...
Do you always fill up at the same petrol station, if so, try another.. could be dodgy fuel
Tom

[Organisys]

maybe the knock sensor has had it?

I've got to try this tomorrow, fingers crossed!

If you replace it, make sure you use the correct torque settings when attaching it, if you don't it won't work.

[GTIrl]

 i think what happens is (someone jump in to correct me if im wrong) that if the brain is getting a false reading from a sensor or if a sensor(s) isnt working then the ecu automatically retards the engine... and i think that can cause the pinking under load.

but i need someone to verify all ive just said cos it might be pants.

i had pinking and back popping and a very loud resonating sound from my exhaust. after ages of timing and re-timing and new knock sensors and blue temp sender and checking and rechecking my exhaust etc etc, what fixed it in the end i think was getting a new airflowmeter when returning the airbox back to standard (there was an old k&n slapped on it...) so possibly check your airflow meter?

[Organisys]

 i think what happens is (someone jump in to correct me if im wrong) that if the brain is getting a false reading from a sensor or if a sensor(s) isnt working then the ecu automatically retards the engine... and i think that can cause the pinking under load.

but i need someone to verify all ive just said cos it might be pants.

i had pinking and back popping and a very loud resonating sound from my exhaust. after ages of timing and re-timing and new knock sensors and blue temp sender and checking and rechecking my exhaust etc etc, what fixed it in the end i think was getting a new airflowmeter when returning the airbox back to standard (there was an old k&n slapped on it...) so possibly check your airflow meter?

It's pants.    Retarding the ignition prevents pinking. Advancing it too much causes pinking.

[rubjonny]

did you set the ign to 6 degrees @ 2200rpm with the blue temp sender disconnected and the oil temp at 80degrees+?  If not that will probably be why its pinking

If you did, then I'd replace the blue temp sender 1st with a new one from VW as this affects the ECUs calculations for fueling and ign advance, and then try a new knock sensor.  Make sure you do it up to exactly the right torque otherwise either it wont work, or will be broken!

While you're checking the timing, double check the static timing is correct, and also double check the flywheel timing mark is actually marked at 6 degrees BTDC!  The haynes tells you how far the mark should be away from the TDC mark, check under 'replacing the flywheel'.

Have a read through my digifant tuning guide as well.

[Bluefox]

Have a read through my digifant tuning guide as well.

Sorry for ignorance, and thread hi-jacking, but where's this guide you speak of?