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Discussion Starter #1
Hi all
Has anyone here using Optimax experienced pinking?
I'm on my fourth tank, and whilst driving today with the windows down (I usually have the windows up with Aircon on) I heard a distinctive rattle (relatively quiet) that I'm almost certain was the sound of pinking. I wasn't working the engine hard (i.e. in too high a gear for the speed) and having owned a car in the past that pinked all the time, I'm pretty sure that was the sound. It wasn't a temporary rattle either, and persisted all the way home, mainly between 2-3500 rpm.
Once this tank is run through I intend to use a couple of tanks of normal unleaded to see if the problem persists (I'm not sure where that leaves me if it does!)
Any thoughts on whether higher octane fuel could cause this?
 
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Discussion Starter #3
Indeed!!

I checked Shell's website for some more info on this, and it indicates that Optimax works by causing combustion to occur earlier than normal unleaded fuel.
I guess I'm just concerned that earlier combustion could cause pinking & long term damage to the engine!?
 

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I've had no personal experience of this, but have heard other people making similar complaints.
 

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Hi,

Using Optimax should stop a car that normally pinks when using regular unleaded.
I use optimax in mine and find the engine pulls better (slightly) throughout the rev range (Not that it ever pinked imn the 1st place).

Modern engines should never pink anyway as the knock sensor will normally just retard the timing slightly so that the pinking goes away.
 
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Discussion Starter #6
I always thought higher octane level meant greater resistance to pinking. Perhaps the computer has overcompensated for it or something?
 

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<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:<hr /><font size="1" face="Verdana, Helvetica, sans-serif">Originally posted by G-147:
<strong>whats pinking???</strong><hr /></blockquote><font size="1" face="Verdana, Helvetica, sans-serif">Something that owners of red Alfas would be familiar with! :D
 
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Discussion Starter #9
Mine pinks a little when moving off on a light throttle.

Should we have our knock sensor checked?
 
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Discussion Starter #11
pinking is pre-detonation of fuel and is very,very bad,in fact as bad as Jack Bad Mc Bad on a bad day.
 
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Discussion Starter #14
you will know if you car sounds like a vauxhall Viva,or you've stopped suddenly and your car is surrounded by firemen
 

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G-147,

Pinking, or knocking sound somthing like a metalic glass breaking sound, something like "ting-ting-ting", following the revs of the engine. Not to worry, your car has a knock sensor, which will signal to the ECU, when pinking/knocking occurs. This makes the ECU retard the timing until the knocking stops. After a while, the ECU will slowly try to advance the timing again, for better fuel economy. And if for some reason your knocksensor doesn't work, one of the infamous Alfa warning lights will come on :mad: .

Relax m8. :cool:

All the best

Hoygaard
 
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Discussion Starter #16
and to add to that excellent reply............Optimax may have a high RON,but it also reputedly has a low MON (the US way of measuring fuel) which *may* mean a tuned car could pink if the ECU has been mapped to the higher RON,but not the lower MON.

er.........I think,or so I think,from what me oracle says.

If you are worried,they can run diagnostics on the ECU at any dealer
 
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Discussion Starter #18
Thanks for the replies, just an update to this, having run nearly half a tank of 95RON unleaded through, same sound persists (still quiet though). Guess I was wrong about it being pinking, (especially after the info about the knock sensor) it's either something else rattling or a characteristic of the T Spark engine sound (I'm a first time Alfa owner!) Only happens at low revs though, engine still sounds glorious above 3000rpm.
 
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Discussion Starter #19
tahts not pinking!! Its the engine barbling,ie the Twinspark sound that says "hahahaha you bought a 3 series"!!!!!! just barble near anyone with a German car and forget about pinking,you would know,it comes from under the car,i bet your sound is from the front?
 
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Discussion Starter #20
I am a complete convert to Optimax - it seems to have sufficient benefits to be justifiable and the engine performs so much better with it than without. It does on a non-motorway run though, use more fuel - which is now around 2mpg lower than 95 RON at 28.4mpg. It is very consistent. I also note that the carbon build up around the exhaust is non-existent cmpared to ordinary unleaded. Is anyone collecting the Top Trump Cards you get when you buy Optimax? £50,000 motorshow car as prize? Must be worth it!
 
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