Rattling noise.

It is called pinging.Get timing checked as that is what generally causes this noise.Mentalmav

 

I've had issues in previous cars where i've put fuel with too high an octane rating in it. No premium.

 

This noise can also be caused by running fuel with to low an octane rating. Try running an octane booster in your current fuel load or buy some higher octane stuff.

 

gas has a higher octane rating than fuel, it sounds as though ur timing has been set up for gas, and when u run it on petrol it will have too much ignition timing advance. go get it tunned.. preferably on a dyno!! what state are u in?

meat head: the heigher octane the better, the less chance of knock or pre ignition (which is what is happening to his car) i think you may have got a little mixed up..

 

Meathead couldn't be more wrong. He higherthe octane the less prone to pinging. Lower octane better chance of pinging. Octane numbers are the resistance to detonation. Better the number the better. Hence people use avgas and c16 race fuels as the octane number is ALOT higher than any pump fuel.

 

Yep. My mistake. I got my bike and my car mixed up. The bike's fuel had to high an octane so was popping (in part) due to undetonated fuel and the car was knocking because of regular fuel being used. :doh:

 

I have all sorts of fuel issues on my bike. I'm sure alot of servo's are selling **** ULP E10 crap as premium. Fill at different servo n pinning goes. Always under load.

 

You could also check your timing, it could be that the engine is tuned to run better on gas than ulp, it would ping like mad on anything less than 98 octane or higher.

 

Timing gets my vote mine was doing same

 

Done a little load testing on the bike. Woolies premium pings like E10 ULP, Castrol premium (non woolies stores) is better than the other, Shell and BP have been good and Matilda. The E10 premium from liberty is better then the woolies premium but still pings a little.

You issues would be timing due to octane ratings.

 

E10 is a strange one isnt it.

Ive tested a bunch of fuels from different shops and the difference is huge.
Even in some of the drag cars I have tuned the difference between the E85 blends is equally big.

Good E10 has an octane (or should have) very close to that of 97-98RON.
Crappy E10 has a rating of about 93RON.
Still better than standard unleaded but not by much.

Detonation can be caused by so many things its impossible to say whats causing the pinging.
Retarding the timing by unbolting the distributor and rotating it back until it stops is one way to stop the problem, but its not solving it.

I would probably lean towards a mixture of jelly like fuel causing a blocked fuel filter, which will lean out the fuel mixture, causing the det.

Take it to your nearest dyno and for what ever they charge for a diagnostic run ($100 or there abouts) you will have the answer you need to solve the problem properly.
All you need is Power/Torque/Air Fuel Ratio/Intake Vacuum to see if everything is ok.