Is it valve noise or pinging? [Euro]

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Originally Posted by dsp26

^^^on top of what you said though if it was the case, i'd be worried about WHY its retarding??? the only thing i can really think of is that those things can get sensitive as when faulty!!! especially if there really is something else vibrating real bad.

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Could be a bad batch of 95 RON. Happened to me a few times when I had 98 Optimax. The worst one that I remember was when the ambient temperature was 35ºC. I was going up an incline in 2nd gear, at about 2000 RPM, I saw the tacho needle go past 2000, hit 2100 and then back down to 2000 RPM again before going up past 2100 RPM. It was weird. My foot was on the throttle and did not move at all. It could have been the electronic throttle, or it could have been the engine retarding. But what was shocking was that I was using 98 RON! Now I use Vortex98 instead of Optimax. Didn't happen again.

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Originally Posted by dsp26

when you downshifted from 5th to 3rd what did the RPM shoot to? could have been coil bind of valve springs from too high RPM... but thats jumping the gun. you have to provide more detail.

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80-90 km/h should be 4000 to 4500rpm. So that shouldn't be the problem.

I find that pinging these days on newer cars aren't nowhere near like the 'can of marbles shaking noise' they used to describe them as. At lower levels its just very faintly heard, more like a zhee..zhee..zhee noise.. a lot of times u can't ever hear it over the road noise - in fact I had to rely on knock sensor readers to confirm my suspicion.

But if the noise happens in 2nd gear but not 3rd gear going up the slope - it doesn't sound like pinging to me? Coz it should happen on higher gears.
I would say its most probably just a resonance at that certain rpm/frequency with something else rattling inside the car. Like the Fuse Box lid someone mentioned? Or the electric windows?

But why use one tank of 98 and one tank of 95Ron? If assuming the Euro ECU can learn to use the 98RON, then everytime u put in 95Ron again it might ping before pulling back Ignition Timing. Not a good idea at all. :(

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Originally Posted by Omotesando

But why use one tank of 98 and one tank of 95Ron? If assuming the Euro ECU can learn to use the 98RON, then everytime u put in 95Ron again it might ping before pulling back Ignition Timing. Not a good idea at all. :(

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Hehe, this is going to being back the old 95 vs 98 RON argument :) . My opinion is that the ECU doesn't make more power with 98 RON, so I don't think it has ignition and timing maps for 98 RON, only 95 RON. Otherwise, Hondata would not have been able to produce that extra power by mapping for 98 RON.

The octane rating is a measure of the autoignition resistance of gasoline (petrol) and other fuels used in spark-ignition internal combustion
^^^ i have also proven this by filling a zippo with the different fuels. 98oct doesn't light at all from the induced spark... 87oct lights. also rememebr that gas NEVER catches fire.. the fumes do...

- this is why people advance the dizzy timing to ignite earlier long before the pistons hit TDC to complete the 2nd stroke of an internal combustion engine. this results in a more complete burn hence producing more HP/TQ.
- this is why it prevents PING/DETONATION/KNOCK... its because its "ignition resistant"
- This is why Integra Type Rs say Premium only by the fuel lid... its high CR therefore creates more heat in the CC and is mopre susceptible to ping.

I have seen proven dyno results of simply switching from 98oct to 100oct (Optimax Extreme) in an untuned car gaining 3wkw all-round. However, 100oct runs leaner due to the ethanol mix.

SAU (Skylines Australia) has a bloke with a dyno proven 30wkw gain just from switching to A TUNED 100oct map!!!

I had a LS1 powered Commodore putting out 245rwkw exclusively on 95Ron Caltex Vortex bought from a small Woolworths petrol store in Forbes, with no knock at all, at any time,.... so bad batches aside (which you can get no matter what fuel) its a good fuel IMO.

I run it in my Euro now and get no better economy or power on Ulimate or Synergy, so it may not be fuel; but it is stil probably the first place you should look. If changing fuels doesnt do anything get your car on a dyno and see if you can replicate the problem.

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Originally Posted by dsp26

I have seen proven dyno results of simply switching from 98oct to 100oct (Optimax Extreme) in an untuned car gaining 3wkw all-round. However, 100oct runs leaner due to the ethanol mix.

SAU (Skylines Australia) has a bloke with a dyno proven 30wkw gain just from switching to A TUNED 100oct map!!!

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Why would the ethanol blend run leaner than 98 RON? Is it because ethanol doesn't comsume as many O2 molecules during combustion when compared to petrol?

Also, Skylines are turbo'd. And with a turbo, you can control the amount of air going in. That's why you can gain so much by mapping for higher octane. Same thing was reported for the WRX. But on an NA engine, you don't gain that much from just a mapping change unless you also change other parts of the engine.

Yes splashalot ... I starting to leaning towards it not being pinging as well.

The noise is not from a loose fitting or a rattle in the engine bay. Its definately coming from the motor itself and not from the exhaust system or some other resonance ... it really does sound like valve noise. Since it starts at around 3500rpm my first guess was it had something to do with the change in valve timing or valve open duration (or whatever it is vtec does) and thats why it only happens between 3500 and 4500rpm.

On the way home tonight it didnt make the noise in 2nd gear, but this time in 3rd gear at around 4000rpm. Only happened once but it was clearly there.

The other piece of information to add is the noise only occurs (if its going to happen at all) when the engine is fully warmed up (like 10km or more travelled), but never when cold or warming up.

Does anyone know if the Euro vtec uses hydraulic tappets (or something similar) in the valve drive system?

Malgib - just take it to the dealer and see if you can reproduce it. I always hate that exercise as things miraculously go away when a Honda head mechanic is in the car!

So the noise is always at that low RPM - never at 6000rpm? Do you get any noise between 6000rpm onwards?

Oh so true yfin! the mechanic taks the car out for a spin and it behaves itself! Thats why i like to have all my facts about me, and comments and inputs by ppl here are a great help when it comes to discussing the problem with the dealer.

cant comment on the 6000rpm+ ... never go there ... cant stand the racket the engine makes, doesnt sound good at all. The engine sounds great from 3000rpm upwards towards 6000rpm, but after that it sounds so strained and stressed ... ugh! Plus, the times I have pushed it up passed 6000rpm I never have experienced that vtec 'kick' I've read about ... in fact it seems to lose acceleration rate if anything, so I now always change gears before 6000, usually 5000 to 5500rpm if I happen to be wanting performance at that time.

I certainly notice the engine kick along strong starting around 4000rpm, but nothing at the 6000 mark. Should it?

similar sound also appeared in our MDX ocassionally.... my first thought was the 95 RON i putted in rather than 98 RON that i always do...
but it only happens few times and its now gone... maybe its the petrol or some other factors not too sure... but since then i've always pay 5 cent more to fill with 98 as opposed to 95 :D

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Originally Posted by aaronng

Hehe, this is going to being back the old 95 vs 98 RON argument :) . My opinion is that the ECU doesn't make more power with 98 RON, so I don't think it has ignition and timing maps for 98 RON, only 95 RON. Otherwise, Hondata would not have been able to produce that extra power by mapping for 98 RON.

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The answer to that is easy.

If say assume (notice I mentioned this both times) the car's ECU is able to learn for 96 or 97RON equivalent fuel quality, then when u are running 98Ron fuel, which in most cases is slightly more since 98RON or whatever MON it runs is the minimum advertised, then the car would be running to the 96-97Ron potential.

And if you put back in 95RON, it will be pinging.

The thing is, IF HONDA bothered to put in a slightly better map for higher fuel RON, it definitely won't be at the 98RON limit anyway ;) More like somewhere in the 96-97RON range.

But if you put in HONDATA and have it retuned to the 98RON, it will still gain power. The thing is, whilst some of the Hondata gains are with increased Timing, most of the 5000-6000rpm gain has to do with the earlier introduction of VTEC as well as cam angle adjustments.

There is another thing that I don't know if I should be insinuating. But IF, assuming the fuel being put in is actually 98.8RON, it could be possible that the aftermarket ECU has been tuned to that potential. So if you get a bad batch of fuel that is only 98.0RON or even 97.5RON as its been sitting in the underground tank for too long, it will activate the revised Knock-sensor activated map pulling off Ignition Timing, much quicker.


Although I'm making assumptions here - the thing is, why use 95RON and 98RON once each? I ASSUME its because for some reason, people THINK 98RON fuels like Optimax is known to have cleaning agents and runs cleaner. That's the same reason why people use Optimax sometimes, even if they normally fuel with BP Ultimate, Vortex 98 or Synergy 98.

That's because Optimax being the first 98RON fuel to come out, has always advertised itself as having that 'cleaning' advantage hahahaha....