I thought that if your engine pinged, it was a result of not having the right octane in your gas. Can the oil you choose cause pinging as well? I've heard people here in BITOG claim that X brand of oil caused their engine to ping over another brand.
oil and pinging
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If oil is getting into the combustion chamber, it can form carbon deposits. These deposits effectvely decrease the combustion chamber volume and increase the compression ratio. This can cause pinging on an engine that does not use knock sensors in conjuntion with an EFI system. If there are other ways for pinging to occur via lube oil, I can't think of how.
Oil has nothing to do with engine pinging (if your "pinging" is related to combustion-related/ignition related situations).
Most of the time, the term "ping" is related to combustion abnormalies or ignition issues.
Most of the time, the term "ping" is related to combustion abnormalies or ignition issues.
There has been a number of people on this board that have said that their engine suddenly stopped pinging after draining brand X from their engine.
If you want scientific proof, it's not going to happen. You just have to go with your gut on this one.
If you want scientific proof, it's not going to happen. You just have to go with your gut on this one.
What if enough oil passes the rings to lower the octane of the fuel charge?
Is it a knock or a ping?
the term "ping" is commonly referred to as spark/ignition/combustion-related,whereas "knock" is related to engine mechanicals.
If it's "knock" then yes, oil may have something to do with it; if it's a "ping" (spark/ignition/combustion-related, with the exception of turbo boost/supercharger which over-advance may cause "knock" as well), then it's not oil-related.
the term "ping" is commonly referred to as spark/ignition/combustion-related,whereas "knock" is related to engine mechanicals.
If it's "knock" then yes, oil may have something to do with it; if it's a "ping" (spark/ignition/combustion-related, with the exception of turbo boost/supercharger which over-advance may cause "knock" as well), then it's not oil-related.
Oh and BTW: it's very difficult to sonically differentiate between a knock and a ping most of the time (to some folk's hearing they sound similar or their description is similar). A continuous "ping" from the combustion chamber/ignition side can be investigated from spark plug colour and ceramic tip body conditions, worse case scenario: a severe ping may knock the ceramic firing tip off of a spark plug causing further mechanical troubles. On the other side: a knock can be heard from mild "rapping" to some low frequency "thump" or even some sharp "rap" sometimes, depending on what part of the moving parts are cuasing the "knock".
All other "knocking" issues, some maybe determined by carefully listening to the engine under certain operating conditions (under load, deceleration/acceleration, cold/hot starts, etc.)
All other "knocking" issues, some maybe determined by carefully listening to the engine under certain operating conditions (under load, deceleration/acceleration, cold/hot starts, etc.)
TallPaul, I don't think oil will decrease Octane. Octane is a term used to measure the relative volatility of a gasoline/air mixture. Gasoline is more volatile than oil. Oil added to a gasoline/air mixture would therefore not make the oil more volatile, but less so. IOW, oil added to gasoline would RAISE the octane.
BTW, Octane, of course, is a misnomer as commonly used today when refering to gasoline. There is a molecule called Octane, and the more of it found in gasoline, the more resistant to detonation it is: a true example of a higher Octane level. After the term "octane" was used long enough, any substance that makes gasoline more resistant to detonation is refered to as an "octane booster", whether or not the octane molecule is present in greater quantities or not.
Short story:
Higher Octane = more resistant to detonation.
BTW, Octane, of course, is a misnomer as commonly used today when refering to gasoline. There is a molecule called Octane, and the more of it found in gasoline, the more resistant to detonation it is: a true example of a higher Octane level. After the term "octane" was used long enough, any substance that makes gasoline more resistant to detonation is refered to as an "octane booster", whether or not the octane molecule is present in greater quantities or not.
Short story:
Higher Octane = more resistant to detonation.
Oil indeed can lower the octane rating of gasoline. I'm not talking about a count of octane molecules, I'm talking about RON/MON or rather octane number as a measurement of pre-ignition detonation or ping. Oil in gasoline can and does lower the effective octane rating of gasoline in 4-stroke engines.
Talk to turbo guys if you want to know the effect of too much oil leaking by the turbo seals in combination with boost.
Talk to turbo guys if you want to know the effect of too much oil leaking by the turbo seals in combination with boost.
this has to do with my GMC 1500 V8...
I was using Castrol GTX for the past couple years, and just filled it with Valvoline... But it could just be the gas as well. I just filled it up at Marathon, and typically, I only use BP/Amoco fuels. 87 octane...
I was using Castrol GTX for the past couple years, and just filled it with Valvoline... But it could just be the gas as well. I just filled it up at Marathon, and typically, I only use BP/Amoco fuels. 87 octane...
Pablo, if I'm wrong, I'm wrong. You are saying an oil/gasoline/air mixture is more volatile than gasoline/air mixture? Doesn't seem logical to me, but, maybe it's because I don't understand something about such mixtures, such as a more volatile molecule in oil that is only expressed when oil is vaporized. Because Oil by itself, non-vaporized, is nowhere near as volatile as gasoline. Interesting.
Personally, I find it hard to believe that oil choice can cause pinging. However, I questioned this very idea myself, since I had the audacity (horrors of horrors!) to use 5w30 in an engine speced for 5w-20.
I have a 2005 Mustang GT, with 4.6L V-8. It didn't ping when new, but after I put a few thousand miles on it (and a few carbon deposits as well), it started pinging for an instant on a hard upshift or sudden stab of the throttle. The knock sensors seemed to be doing their job, since it was only for a split second. Still, I didn't like hearing it, and wondered if it was doing some long term damage. These engines are speced for 87 octane, which I thought might be a stretch for an engine with 9.8/1 compression.
I ran some Techron through it to eliminate carbon, as well as some Amsoil PI. I've also switched to Chevron gas exclusively, instead of el cheapo places like Racetrac. Now, it pings very lightly only under extreme situations on 89 octane, and doesn't ping at all on 93. Before these treatments, it even pinged a little on 93, and about as bad on 89 as 87. I realize this is a little off topic, since pinging vs. oil was the issue, but I thought my experience might be of value to someone. After all of this, my thought is, they tune these engines for the sake of emissions and economy on the ragged edge of detonation. You know, maximum advance and as lean as possible. All you have to do is get something a little out of range (e.g. fuel quality or a little carbon buildup), and you'll hear that unpleaseant rattle. My owners manual says occasional light pinging is normal. Sorry, but I don't want to put my pistons through that abuse. Just my 2 cents worth, but I hope it's worth a little more than that to someone.
I have a 2005 Mustang GT, with 4.6L V-8. It didn't ping when new, but after I put a few thousand miles on it (and a few carbon deposits as well), it started pinging for an instant on a hard upshift or sudden stab of the throttle. The knock sensors seemed to be doing their job, since it was only for a split second. Still, I didn't like hearing it, and wondered if it was doing some long term damage. These engines are speced for 87 octane, which I thought might be a stretch for an engine with 9.8/1 compression.
I ran some Techron through it to eliminate carbon, as well as some Amsoil PI. I've also switched to Chevron gas exclusively, instead of el cheapo places like Racetrac. Now, it pings very lightly only under extreme situations on 89 octane, and doesn't ping at all on 93. Before these treatments, it even pinged a little on 93, and about as bad on 89 as 87. I realize this is a little off topic, since pinging vs. oil was the issue, but I thought my experience might be of value to someone. After all of this, my thought is, they tune these engines for the sake of emissions and economy on the ragged edge of detonation. You know, maximum advance and as lean as possible. All you have to do is get something a little out of range (e.g. fuel quality or a little carbon buildup), and you'll hear that unpleaseant rattle. My owners manual says occasional light pinging is normal. Sorry, but I don't want to put my pistons through that abuse. Just my 2 cents worth, but I hope it's worth a little more than that to someone.
Oh, by the way, despite Ford's saying not to use premium fuel, I'll do so from now on, thank you very much. They won't have to rebuild my engine after warranty has run out; I'll have to. It's unpleasant, as well as embarassing to hear pinging in an almost new car. I'll go the safe route, and spend the extra 20 cents per gallon for 93 octane. Might be a waste of money for some people, but it can't hurt anyone.
I agree, I don't think your oil choice will cause pinging. That wasn't my point. But oil mixed with gasoline will cause pinging in a high compression or forced induction 4 stroke engine. I suppose this could happen via oil from the cylinder walls - but it seems you would have worse problems than pinging at that point.
I don't think an oil gas/mixture is more volatile than gasoline itself.
I don't think an oil gas/mixture is more volatile than gasoline itself.
Rainama>On my 05 4.6 Vic my manual says use 87 octane and not to use anything higher.They claim light ping is normal in a 4.6.
I wouldn't use 5w30 since its under warrenty though it shouldn't do it any harm.I heard a Ford service advisor tell a customer awhile back that his warrenty could be void by using anything other than 5w20.Since Ford uses a synthic blend the 5w20 should work.
Since your Mustang is a 05 i'm surprised it built up so much carbon already.
My 99 4.6 used to ping like a mother-f.With no knock sensor in the 99 i had no choice but to burn 93 or it would ping and knock like crazy.The Miami heat and the a/c on 24/7 and nightmare traffic didn't help.
I wouldn't use 5w30 since its under warrenty though it shouldn't do it any harm.I heard a Ford service advisor tell a customer awhile back that his warrenty could be void by using anything other than 5w20.Since Ford uses a synthic blend the 5w20 should work.
Since your Mustang is a 05 i'm surprised it built up so much carbon already.
My 99 4.6 used to ping like a mother-f.With no knock sensor in the 99 i had no choice but to burn 93 or it would ping and knock like crazy.The Miami heat and the a/c on 24/7 and nightmare traffic didn't help.
Two things come to mind for me regarding oil type and pinging (sparknock). If the oil somehow effected a better ring seal then maybe the increased compression could increase the possibility of pinging. I admit that this hypothesis is really stretching things a bit but it sounds possible... maybe? The other scenario allready mentioned, and I believe this is very possible is oil getting past rings and/or valve guides in to the combustion chamber. Thus lowering the effective octaine rating of the mixture. I have personally witnessed an oil burner that sparknocked heavily under acceleration. Adding a generious dose of STP both reduced the oil burning tendancies and eliminated the sparknock.
OK. I agree with that last part. That's why the presence of oil in the combustion chamber would not seem to my way of thinking to cause pinging.
But, maybe you are saying that oil mixed with gasoline/air is more prone to detonation than gasoline/air only? Detonation and volatility certainly aren't necessarily equal. If you are not saying oil/gas/air is more prone to detonation, why is it that oil increases the tendency to prematurely detonate (assuming pinging is due to premature detonation)?
This really bugs me...I don't like misunderstanding something that seemed so straight forward to me. What am I missing?
Titan - think about how a diesel engine works.
Pabs is right on here.
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