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Discussion Starter · #1 ·
Recently bought 1998 1.8T the car is very nice but I have noticed that
it pinks quite badly under load (3 guys un the car in 3rd gear at
2000rpm).

The car is unmodified and doesn't over heat or anything like that.

Any one got any ideas?
 

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My first guess would be a defective knock sensor, or perhaps a coolant temp sensor.

You won't know for sure until you get the ECU read for error codes.
 

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My first guess would be a defective knock sensor, or perhaps a coolant temp sensor.

You won't know for sure until you get the ECU read for error codes.
Spot on, what fuel are you using?
 

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Discussion Starter · #4 ·
95 unleaded, standard stuff.

Looks like its going to have to be a trip to the dealers for me.

Anyone know a good VAG specialist in south London that has VAG diagnostic gear?

Knew the price I paid for the car was too cheap! ;-)
 

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Discussion Starter · #6 ·
I'll give the optimax a try. I spoke to a VAG specialist just now and
he said it may not have the right plugs fitted. The 1.8T needs special
plugs aparently that are ?10 each.

I know this is true of VR6's (RIP my baby) but is that true of the 1.8T?

Thanks
 

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I had this problem with mine. It turns out that VW petrol engines are
not designed for 95ROIN standard unleaded. As the dealer pointed out to
me, on the inside of the filler flap it says it needs 98ron fuel, which
is super unleaded. I use Optimax and it cured the problem within a
tankful. Don't be to put off by the price either though. The fuel
consumption is significantly better with optimax then standard fuel, so
in the end you make up the differnence.
 

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Its when the engine makes a pinking/pinging sound either through the revs or at a standard speed!

I would give optimax a try mate. The 1.8T's seem to love it, i know mine does....TOO MUCH! [:O]
 

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Its when the engine makes a pinking/pinging sound either through the revs or at a standard speed!
I'm confused. Is this actually more of a clatter than "ping" sound? I used to get that loads before I changed over to Optimax. I always get confused when people say pinking, as that doesn't really describe anything? The colour pink?
 

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I had this problem with mine. It turns out that VW petrol engines are not designed for 95ROIN standard unleaded. As the dealer pointed out to me, on the inside of the filler flap it says it needs 98ron fuel
Says 95-98 on mine. Sure it'll run on 95, but less than optimally. I believe manufacturers' output figures are based on the highest recommended grade. In Germany, where many things we consider as high grade are the norm there, Shell has V-Power, 100 RON [:O]
 

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I thought pinking was when the fuel ignites too early. Wasn't sure of the reasons why.....did a quick google and came up with the following........

1) Unleaded fuel, generally being of lower octane rating, will render the car more susceptible to detonation or pinking from sources not directly attributable to the fuel, like oil dilution of the petrol, localised overheating, etc

2) Use of low octane fuel without engine adjustment or octane lifting additives can give rise to detonation in the combustion chamber rather than steady burning. this detonation is heard as pinking and can be very damaging to engines, particularly it can cause piston failure.

3) I understand that the higher the Octane level in the fuel, the more the protection that your car's engine's combustion chamber has from detonating / pre-igniting /' pinking' ... these apparently are the 'tinkling' sounds you might hear from your engine if you go up a hill under full throttle load which may occur from too weak a mixture or too far advanced ignition timing for the grade of petrol being used. Higher Octane levels therefore can protect your engines from these sorts of symptoms. I am informed that Higher Octane levels in the fuel used can prevent the internal 'knocking' in the combustion chamber that can occur from using a lower Octane fuel.

Hope some of that helps.

I used to read the Shell Optimax forums every now and again. Usually some interesting topics on their, even if Shell Moderators do skirt some issues.
 

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"Pinking" or "detonation" is when the fuel is ignited and does not burn correctly. Usually when the spark is fired you get a steady flame path from the plug which spreads across the piston top to give a nice even explosion to push the piston down.

When then detonation occurs, the flame path is all over the place. Its an uncontrolled explosion. It can start at each side of the cylinder and smack together in the middle. Not good, and if left, in extreme cases it can make a hole in the top of the piston! It is caused by excessive heat and pressure in the cylinder. If the ignition timing is too far advanced it will cause detonation, thus a faulty sensor could be telling the ECU to fire the sparks at the wrong time.

It sounds like a metallic rattling. God knows who came up with the term "pinking"??!

Yes, the 1.8T requires certain plugs, but then all engines need the correct heat range plug. This could well be the cause here, so get them checked. And yes, they are expensive from VW. You can get the same plugs from Halfords a bit cheaper probably.
 

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LOL, while I was writing my essay, you got in there first!!

Detonation and pre-ignition are slightly different. Pre-ignition is more caused by hot carbon deposits in the combustion chamber, kinda like a glow plug. But its all kinda the same subject.

Yeah, the higher the octane, the greater the protection against knock, pinking, detonation etc.

Forgot to say that I would expect maybe a tiny bit of detonation when changing fuel, but the ECU should learn and adapt pretty soon.
 

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Damn, I also forgot (doh). When you get your car chipped, it is a good idea to change your spark plugs to a range cooler. Alot of peeps overlook this.
 

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Discussion Starter · #18 ·
Just wanted to update you guys on my pinking problem. Soon after i
bought the car (a day or so) the pinking stopped and all was well. I
wonder if the ECU just adapted to the 95RON fuel?

Anyways last week I got my car Upsolute chipped and added the NGK BKR7E plugs. I also have a forge DV and Green filter.

Unfortunately the pinking has come back with a vengance and it really
bad at full boost 3000-4000rpm. I filled up with optimax but within 10
miles of driving the gearbox failed on my car with spectacular snapping
and grinding sounds!

So the car is getting a new gearbox this week and then I'll be trying to sort my pinking issues.

Have any of you guys had this problem with Upsolute on early AGU engines? How long does it take for the ECU to adapt?

Thanks

Ron
 

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shit dude that is bad luck!  I have APR on my AGU and some times when she gets hot the engine note will change slightly and a beleive that may be the onset of pinking, but i use optimax all the time and still have multi electrode spark plugs (which is prolly the reason for the engine note change when hot).  With a chip you should , from what i have gathered, run atleast super unleaded, use high grade oil, Castrol RS or Mobile 1, and change the plugs.
 
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