VR6 Pinking

[Roger Blassberg 0]

My first visit - good to meet all you like-minded ladies and gents. Maybe and old question, but all advice is welcome.

My VR6 pinks like mad under acceleration once operating temperature is reached, running on Optimax. New cylinder head including valves, guides, springs, seals, cams 6000 miles ago. The pistons looked good when the head was off. Coil pack ignition. Exhaust gas analysis shows no problems at idle, so I assume the lambda is ok and not weakening the mixture outside the specified range. Water temperature about 105 in slow traffic, much lower at normal driving speeds, fans both operational, new thermo switch, new supplementary water pump, oil temperature often over 110.

 

How many knock-sensors are there, and where are they? Are they prone to failure/malfunction? Oil temp seems high to me, certainly a lot hotter than ever had with 16V 2.0 litre engine code ABF, so is there still an overheating problem? I suspect that the previous owner had re-chipped the EMU, but surely the knock sensors would do the necessary to the timing to prevent pinking.

 

all the best

Roger

[Kevin Bacon 5]

Moving to problems and there is a Knock sensor per bank of cylinders. Connections for both are on their respective engine mounts. So check around the front and rear of the block for dodgy wiring.

 

The knock sensors generally aren't needed until you're at 3500rpm at Wide Open Throttle and is where you hear it the most. Have you got VAG-COM? That will tell you if the knock sensors are dead.

 

Everything else about your engine seems normal from what you've said. Oill is a little on the high side but not drastic.

 

You can check for chipping by pulling the ECU out. The standard chip is hardwired to the main board, so if you see an IC socket, it's been chipped.

 

K

[PhatVR6 0]

I've only ever heard mine pink when it got realy hot. Does it ever overheat at all? oil and water temps don't seem THAT high really, is it any worse when the water temp is around 100?

 

If it's been chipped and you're running regular unleaded then it will pink if your knock sensors aren't up to the job., try running it on super or optimax and see if it goes away.

[Timo. 0]

PhatVR6, he said he's running it on optimax :roll:

 

 

timo :mrgreen:

[Kevin Bacon 5]

He he I 'skim' read the post too and didn't spot that!

 

In that case one or more knock sensors are disconnected or broken.

 

You need VAG-COM to be sure or get it scanned somewhere.

 

K

[Timo. 0]

8)

 

Now to embarass myself..... :oops: What does pinking sound like?? just been searching the forum but I cant find the answer. Sorry :oops:

 

timo

[dr_mat 0]

How old are you?! You've never heard a car pink?!

Wow!!

Had a transit van on rental for the day once about 8 years ago. It was pinking like mad, really really badly. I just assumed it was something metallic that was loose on the engine, so I drove on (didn't have time to try and fix it anyway), and lo and behold the head gasket went awol.. :)

So there you are it sounds roughly like a piece of metal rattling against the engine block. A fairly light piece of metal...

[Kevin Bacon 5]

Like a metallic clattering, you will know it when you hear it!

 

Find a quiet road, stick it in 3rd at about 35-40mph and pin the throttle to the carpet and take it all the way up to 6000rpm.

 

If you don't hear any clattering/knocking, you're OK.

[dr_mat 0]

(It's actually an onomatopaeic word - the word is supposed to sound more or less like the actual sound, so...)

[Timo. 0]

Mmmmm...... think I know what you mean. Just never made the association between the sound and what the engine is actually doing (pinking). cheers

 

timo

[Kevin Bacon 5]

So what's the relationship between the sound detonation, and the word pink then?

[dr_mat 0]

Think "tink" - the noise of two light bits of metal hitting each other the "pink" comes from the fact that it's not actually metal hitting metal, so the attack on the noise (deadened by the engine block) isn't so harsh. Hence "pink".

Roughly...

[Kevin Bacon 5]

LOL..... you could bullshit your way out of an Iraqi interogation room :lol:

[dr_mat 0]

I work in technical support... can you tell? :)

 

Seriously though - that's where the word comes from. It has no technical roots, it's purely descriptive.

[Kevin Bacon 5]

Thanks for sharing your intimate knowledge of the English language with us, you nutter! :-P

[Henny 0]

yup, I knew that too, dr_mat, so I'll back your "bull" up... 8)

 

Only thing is that I wouldn't have been able to spell "onomatopaeic" :oops: :roll: :lol:

[corradovr6sc 0]

Americans say pinging though so they think it sounds different :)

[dr_mat 0]

yup, I knew that too, dr_mat, so I'll back your "bull" up... 8)

 

Only thing is that I wouldn't have been able to spell "onomatopaeic" :oops: :roll: :lol:

 

Thanks Henny! 8)

 

Oh, and I guessed the spelling... :)

 

I figured most people weren't gonna know if I got it wrong anyway! ;) :-P

[Henny 0]

Oh, and I guessed the spelling... :)

 

I figured most people weren't gonna know if I got it wrong anyway! ;) :-P

 

:roll: :lol: :lol:

[Roger Blassberg 0]

Thanks for the advice. I'll have the knock sensors checked.

Please will someone tell me about VAG-COM - is it the fault analyser that plugs into the socket under the gear stick gaiter? Or is it a software package I can get hold of for use with a laptop/adaptor cable? Where do I get it, and about how much?

 

Incidentally, I have just done the headlight wiring loom modification - literally a brilliant improvement.

 

Roger

[Kevin Bacon 5]

All you need to know is here:- http://www.ross-tech.com