Sudden and severe pinging between 4-5000 RPM

[NeroGuzzi]

The engine originally pinged constantly when hot throughout the rev range. The GT ECU/PCV/AT cured the constant pinging. A problem I still have is a sudden and severe pinging when I moderately twist the throttle between 4-5,000 RPM. This has happened with the bike since new for over 15k miles, but the frequency has now increased. Although the ECU reflash, PC5, and AT have done wonders for the engine's performance, it has not eliminated this one problem. Here is some background:

-2007 B11
-The severe pinging is immediately followed by a significant drop in power
-This will happen when the engine is hot, regardless of outside temperatures
-A moderate twist of the throttle b/w 4-,5000 RPM can result in severe pinging. For example, trying to spin up RPM's to change gears, changing lanes to pass a vehicle in the slow lane, or exiting a turn. It happens at a very inconvenient, and might I add, dangerous point of the power range.
-The severe pinging event is not necessarily repeatable. It could happen only once on a ride and not again despite replicating the same conditions and situation.
-A WOT from 4-5,000 RPM will likely prevent the sudden pinging
-A WOT from anywhere below 4-,5000 RPM will bypass the potential of a pinging event completely
-There is no rattling, pinging, or knocking any other time. The engine sounds and runs great all other times
-The noise seems to emanate more from the RH cylinder
-I liken the noise to what you would hear if you would have manually advanced the timing too much on an old school V8
-TPS, TB Balance, and tappet gaps are good
-All maintenance intervals have been either met or exceeded. Outer plugs have tended to wear a little, but inner plugs looked almost new when I changed them.
-The AT does not make radical adjustments after a sudden and severe pinging event.

Although the engine did this before I added mods, here is my current set up:
-PC5, ECU reflash, AT
-13.2 AFR throughout the rev and throttle range
-GT-r Y-pipe
-Stock silencer
-GT-r open air lid with K&N filter

The bike is no longer under warranty. When it happened a few times under warranty, I mistakenly attributed the symptoms to lean fueling. Any feedback would be appreciated. Thanks.

 

[Mal]

My Sport1200 (2V) intermittently does similar. Not very often but seems to be when hot or on lower octane fuel. OEM except for airbox snorkel removal 15,000km.

Most noticeably occurring during a top gear roll on but a bit lower down than yours 3,500~4,000 Can also occur uphills in lower gears.

Sound like a rapid chat, chat, chat, chat, chat, chat. I assume it’s pinging but yes it does seem like the sound you would hear from manually advanced timing. Valves and pushrods are relatively quite otherwise.

 

[Spaceclam]

Welcome to my world! That's almost my bike to the T.

Once upon a time, i went to a track day. ON the freeway ride there, it was about 90 degrees. I could not accelerate AT ALL in 6th gear, or it would ping like crazy. This was before fueling.

The fine techs at the now deceased mgto told me they wouldnt warranty it because the bike had a small accident, as well as being about 20 miles late for it's first service, even though i had informed them about it even before it's first service.

Fueling helps but it wont fix it. All you can do is reduce heat, add octane, or downshift when necessary.

I have been considering ceramic coating the exhaust port, and removing the powdercoat to reduce heat. Currently, it takes 95 octane to run properly.

 

[Roblatt]

Mine behaves similar to Mal's. Only in the summer months. I've tried all the various fuels and the behavior is the same. My question would be, can you add too much octane so as to cause damage? If I use 98 octane, and add octane boost, can I cause damage?

BTW - stock '06 B11

Robert

 

[jimbob]

My symptoms to a T.

No matter what throttle setting there would be pinging. No matter what gear would ping.

Would only ping when it 'felt like it'. ie; could not replicate it.

However if revs were dropped to below 4000 problem would go away until throttle was redruced.

Not as bad in Winter. The worst experience was after riding for a period of over 2 hours, at a temperatue of 14 degrees centigrade and lasted until I stopped for a pint.

Running stock exhaust.

Jimbob

 

[arci]

Yes I have similar issue. The pinging sound is detonation in the cylinder. To eliminate, the need to change the ignition timing depending on engine temperature . Maybe it would help verify the functionality of the temperature sensor.
This problem manifested itself even before this my modification. After the modification was to reduce, but not to eliminate this problem.


I have this mods on Norge 1200:
Mistral muffler - open
Orig ECU - Map version NG17
Rapid Bike 3 + RB O2 modulator
BMC Air filter

 

[PP-1753]

Over on this side of the pond, I can only use 98 octane - all the others cause similar problems. Getting the ECU upgraded to the latest map was the best thing (1200 Sport), but in your case I don't think this is the problem. The temperature sensor though might need some work.

I actually broke the plastic spacer on mine trying to unscrew the temp sensor out (yeah right the thing is moulded not screwed). Little did I know that this would be good. I turned up one from some brass bar, closed the gap between the sensor and the bottom of the spacer, and added "sufficient" grease to ensure good thermal contact. Voila! She's all good mate, you bewdy bottla!

Older Guzzis also had this problem and I do believe you can get a brass spacer from someone, somewhere to fit all the later motors, from 1100 up - it's the same fitting. Experiment or search some of the forums or someone may even help out further here.

Gotta love technology...

 

[NeroGuzzi]

Well, it looks like it's not just my bike and it is certainly not limited to the 1100 motor. Ok, I'll start with the temp sensor and brass insert.

 

[arci]

So I tested the sensor. All right. Impedance changes according to the table in the service manual and the oil temperature of 130°C "ecu" shall overheating engine. During a test drive when the engine overheated, this sound "pinging" occurs from 3500-5000 depending on the acceleration. When determining the cooling engine, the sound gradually disappeared.

Conclusions: The only thing that may help them update the version of ECU to NG18

 

[Mal]

I though the GT ECU reflash (which I believe changes the timing) might help with this but I guess only so much.

The engine originally pinged constantly when hot throughout the rev range. The GT ECU/PCV/AT cured the constant pinging.

I also run 98 RON, which keeps my Sport running smooth 99% of the time.

 

[vivo]

I was just wondering... obviously the pinging doesn't happen on brand new bikes...else there would be complaints. I'm not all that mechanical so forgive my questions.... has anyone changed out all the plugs, plug wires and leads? I know it may be misguided but I was wondering if faulty spark can cause similar symptoms? Is there anything mechanical that might effect timing advance? Just looking for the stupid simple or dupid dimple

vivo

 

[Spaceclam]

no, they do it when they are new, too. Well, some of them do.

modifying my squish did not affect my pinging.

The ideal case is to redesign the piston and combustion chamber, which they did with the 8v. inch: Less surface area inside the chamber means less heat, and no hemi dome means less spark advance, which again means less heat.

The next to ideal case is to add some octane. Octane booster sucks, you need real fuel. This is expensive.

After that, comes reducing heat. Proper mixture is the first step, though it wont solve it. Although you'd think that reducing heat comes before adding octane, reducing heat either requires a loss in power (spark retarding) or significant investment and gamble (coatings and stuff). IN theory, reducing the temperature of the head will reduce the tendancy to BEGIN to ping, but once it does, you are still no better off. I'm not sure what the results would be in practice, and im still considering it.

Pinging is self-sustaining. When it pings, the inside gets REALLY hot, which causes more pinging. If the temps are never high enough to cause pinging in the first place, then problem solved.

 

[jimbob]

Over on this side of the pond, I can only use 98 octane - all the others cause similar problems. Getting the ECU upgraded to the latest map was the best thing (1200 Sport), but in your case I don't think this is the problem. The temperature sensor though might need some work.

I actually broke the plastic spacer on mine trying to unscrew the temp sensor out (yeah right the thing is moulded not screwed). Little did I know that this would be good. I turned up one from some brass bar, closed the gap between the sensor and the bottom of the spacer, and added "sufficient" grease to ensure good thermal contact. Voila! She's all good mate, you bewdy bottla!

Older Guzzis also had this problem and I do believe you can get a brass spacer from someone, somewhere to fit all the later motors, from 1100 up - it's the same fitting. Experiment or search some of the forums or someone may even help out further here.

Gotta love technology...

Will you advise where the sensor is and describe in greater detail what you did.

Am a bit confused how the 'fix' was done. Probably because I am on the other side of the ditch.

Jimbob



Jimbob

 

[arci]

B) Yes, heat is the biggest cause of pinging. But this creation can be prevented, timing advance. :idea:
This timing must be dependent on the temperature of the engine.
Maybe it would help optimize the ECU - "GT-Rx Performance ECU"
:?: Does anyone have any experience with "GT-Rx" treatment?

Another thing that helps is to polish the combustion chamber (Cylinder head and piston), but it is hit into the engine.

 

[PP-1753]

Hey JimBob and others,

The temperature sensor is inboard of the injection tract for the R/H cylinder and can be seen with a blue plug on it and held in place with a snap wire. It can be removed in situ but you must be very careful. Removing the tank will help somewhat but it is still cramped in there. The correct solution (and well documented by Pete Roper on this forum) is to remove the temp sensor from the plastic spacer, put in some quality grease at the bottom and very carefully (and slowly) screw the sensor back in. I say slowly as you need to let the trapped air escape as you screw it down and with grease in there, the air gap is pretty much non-existent.

I broke mine so I went to the effort of making a brass spacer instead of the plastic as has been done on many a square barrel Guzzi. The theory behind this is the temp sensor will let the ECU know when the head is up to temperature and that full advance and fuelling can now commence. If there is poor or intermittent heat transfer, the ECU can get quite confused and start doing naughty things to the ignition. BTW the spacer is the same as is found in many auto applications to check water/oil temperatures on engines and should be available easily if you mess up and break it, so be careful!

If you go down the path of making your own, you will need a set of Metric fine taps. These are not found in most places and will need to be ordered. It might be better to see if you can purchase a brass spacer...

This may or may not cure/assist in curing the problem, as many have found it makes diddly squat difference. But others have found it useful - I was just clumsy/ignorant and paid the price but I was lucky I had the facilities to make one. But the bike was off the road for a few days...

 

[john zibell]

Hey JimBob and others,

The temperature sensor is inboard of the injection tract for the R/H cylinder and can be seen with a blue plug on it and held in place with a snap wire. It can be removed in situ but you must be very careful. Removing the tank will help somewhat but it is still cramped in there. The correct solution (and well documented by Pete Roper on this forum) is to remove the temp sensor from the plastic spacer, put in some quality grease at the bottom and very carefully (and slowly) screw the sensor back in. I say slowly as you need to let the trapped air escape as you screw it down and with grease in there, the air gap is pretty much non-existent.

Actually not grease, use a thermal mastic, similar to the paste used in PC CPU heat syncs also used in AC systems. Something like this http://www.grainger.com/Grainger/items/4E847

 

[GrahamNZ]

If faced with sudden and severe pinking, the first thing I'd do is try fresh fuel of reliable quality. If that didn't do the trick, next fit new outer spark plugs. Try the simple things first.

 

[Brian UK]

Anyone ever actually checked the ignition timing on a bike which pings? I don't mean the figure displayed by VDSTS or Axone, I mean with an independent method like an old fashioned timing disc?

 

[vivo]

Hey there Andrew...

Excuse if I missed something....

Much of what you've done has been based on assumption. The oldest posts if I remember were less conclusive as to pinging... I may be wrong

If it were me I would try to eliminate the noise, which is pinging as you have said. If higher octane is a fix why haven't you started there? If a higer octane can reduce or eliminate detonation then it stands to reason you need to prove you can stop the ping. This is where I would have started. I would want to know if it is pinging and I would want to know what fuel quality means to the situation...

Have you considered a homemade cool can. Will it cool the fuel enough to help? Is it possible to cool the fuel thus reduce engine heat if only as a trial?

I have to wonder why some bikes might ping but others do not? I can understand the climate the bike runs in has an effect, elevation, fuel quality, rider input, and set up. I have a harder time understanding why combustion chamber design even accounting for variation in bikes allows some bikes to detonate but others to run without problem and given this isn't really a small issue I wonder why a manufacturer would allow engines to reach production that have the ability to self destruct? That doesn't make much sense it me so if I am assuming it is not related to combustion chamber design then it must be something else? Timing is more reasonable an assumption but it might be anything? So I am wondering why you don't remove the easy stuff first before re invention of the chamber design?

Just trying to look at this with new eyes... duhhh

vivo

 

[NeroGuzzi]

If faced with sudden and severe pinking, the first thing I'd do is try fresh fuel of reliable quality. If that didn't do the trick, next fit new outer spark plugs. Try the simple things first.

Graham, that was my first reaction as well. I have tried dozens of different gas station high octane fuels to no avail. I have replaced both plugs with the exact factory prescribed replacements. Again, with no change. I do suspect the 10% ethanol fuel we have here is a contributor to the problem.