Hi,
Some comments made earlier refer to me with an invitation to respond
1 - I am not a Guru on UOAs (see below) and others on here have at least as much experience as I do
2 - Tear down inspections usually include all except removing the crankshaft really. This includes extracting all liners and dissassembling pistons. Measure-up must occur to see if the major wearing parts are within the Manufacturer's specifications for reuse
3 - A significant comparison of lubricants did occur and this is well documented. I cannot make this information available. In the past I have published pictures of one of my engine's components(liners, bearings etc). In this particular case the engine's Manufacturer carried out the teardown and reassembly - the engine had done 1.12m kms (around 695k miles) as I recall. It has now done in well in excess of 2.5m kms - I no longer own it
I always sold my vehicles at around 1m - 1.3m kms and did not carry out any major rebuilding work!
4 - Tear down inspections in my field (for a number of engine/vehicle Manufacturers, Oil Companies and others) have occurred over many many years commencing seriously around 1960! They include all manner of petrol and diesel engines from around the Globe!
5 - It is common when field testing lubricants (past practice at least) to select a series of engine families operating in a similar application. And of course where utilisation is high so that results accumulate quickly and where UOAs (as only one factor) can be taken on a systematic basis. This testing may take two or three years and may rack up several million kms. Formulation changes typically occur during this process
6 - Yes I do promote using the Manufacturers Approved lubricanst and viscosities as mandated. These (viscosities) can change of course on a Global basis!
I won't go on any more.........................however:
I wrote this as Post a couple of days ago for another Thread and never Posted it - perhaps it is still relevant!
STARTS
Perhaps an opinion on reality regarding basic (BITOG type) single pass (SP) UOAs might help
SP UOAs are a great "tool" in assessing the condition of a lubricant and its suitability for further service. If an engine condition issue exists (such as an internal coolant leak) that affects the condition of the lubricant and this is interpreted correctly (and other supporting data is also available) a deteriorating condition may be able to be halted then and there
Wear metals are another story however and a SP UOA is only a very rough and usually inaccurate guide to what is wearing and at what rate. Trending may assist this process but this takes time. Sadly it is usually too late once "conclusive" data is accumulated
Knowledge of the engine's (or component's) metallurgy and the lubricant's formulation structure are also helpful ingredients in assessing UOAs correctly
That said, I have used trended UOAs for nearly 50 years to:
a) dispute Engine Manufacturer's performance claim's regarding serious engine failures when under Warranty (various Warranty claims accepted)
b) confirm that incorrect lubricants were used that caused a series of major engine failures (various Fleet's fault)
c) confirm that inaction when the lubricant's condition was poor resulted in very expensive engine failures (various Warranty claims denied)
d) obtain reliable maximum OCIs for Fleets
e) select appropriate lubricants for the application (Fleets)
f) change the design of various major component's (engines, diffs, gearboxes)
g) change the formulation of various lubricants and their intended application
h) satisfy various other lubricant/lubrication purposes
As for sudden major "incidents" I have never seen SP UOAs conclusively predict a turbocharger failure, highlight excessive cam lobe wear or cam roller spindle failure, predict-isolate excessive ring wear (except where serious air leaks are present - silicate/iron levels linked). I have never seen excessive cam chain or oil pump wear isolated - the list goes on. The list is long! Trended UOAs may have highlighted a need to monitor conditions more closely in some of these circumstances however, and in certain instances they did!
So IMHO predicting excessive ring pack wear in isolation would be very hard using basic SP UOAs as the sole diagnostic "tool"! If only it was all so easy!!!
Comparing lubricants via wear metal uptakes rates may be possible is certain conditions. These would include same engine family, predictable application and operation and some millions of miles/hour of use - withe each lubricant! Easier waya are used today such as RATT and the likes - this equals wear measurement in controlled conditions and in real time
Incidently my first Paper on UOAs was written in 1975. This was done after spending time in the USA and Europe on a "Technical Industry Fellowship" that embraced working closely with the ATA, Shell, Castrol, GM, Chrysler, Leyland, Cummins, Detroit-Allison, Scania, Volvo, Daimler Benz, ZF and the Trucking Industries of Germany, Sweden and Denmark.
At 70 and retired, I am still learning about lubricants, their application - and about UOAs!
I have no "linkage" to any Oil Company. I once (40 years ago) worked for Caltex-Chevron in a Technical capacity in Scandinavia. I have worked very closely with Shell, Castrol and Mobil as a Commercial user, Road Transport Industry Technical Advisor and as a professional Consultant!
ENDS
Please do not refer to me as an "Expert" or a "Guru" on lubricants and etc - I only Post because I enjoy it and can share my experience and maybe help others. I seek no kudos from this!
Some comments made earlier refer to me with an invitation to respond
1 - I am not a Guru on UOAs (see below) and others on here have at least as much experience as I do
2 - Tear down inspections usually include all except removing the crankshaft really. This includes extracting all liners and dissassembling pistons. Measure-up must occur to see if the major wearing parts are within the Manufacturer's specifications for reuse
3 - A significant comparison of lubricants did occur and this is well documented. I cannot make this information available. In the past I have published pictures of one of my engine's components(liners, bearings etc). In this particular case the engine's Manufacturer carried out the teardown and reassembly - the engine had done 1.12m kms (around 695k miles) as I recall. It has now done in well in excess of 2.5m kms - I no longer own it
I always sold my vehicles at around 1m - 1.3m kms and did not carry out any major rebuilding work!
4 - Tear down inspections in my field (for a number of engine/vehicle Manufacturers, Oil Companies and others) have occurred over many many years commencing seriously around 1960! They include all manner of petrol and diesel engines from around the Globe!
5 - It is common when field testing lubricants (past practice at least) to select a series of engine families operating in a similar application. And of course where utilisation is high so that results accumulate quickly and where UOAs (as only one factor) can be taken on a systematic basis. This testing may take two or three years and may rack up several million kms. Formulation changes typically occur during this process
6 - Yes I do promote using the Manufacturers Approved lubricanst and viscosities as mandated. These (viscosities) can change of course on a Global basis!
I won't go on any more.........................however:
I wrote this as Post a couple of days ago for another Thread and never Posted it - perhaps it is still relevant!
STARTS
Perhaps an opinion on reality regarding basic (BITOG type) single pass (SP) UOAs might help
SP UOAs are a great "tool" in assessing the condition of a lubricant and its suitability for further service. If an engine condition issue exists (such as an internal coolant leak) that affects the condition of the lubricant and this is interpreted correctly (and other supporting data is also available) a deteriorating condition may be able to be halted then and there
Wear metals are another story however and a SP UOA is only a very rough and usually inaccurate guide to what is wearing and at what rate. Trending may assist this process but this takes time. Sadly it is usually too late once "conclusive" data is accumulated
Knowledge of the engine's (or component's) metallurgy and the lubricant's formulation structure are also helpful ingredients in assessing UOAs correctly
That said, I have used trended UOAs for nearly 50 years to:
a) dispute Engine Manufacturer's performance claim's regarding serious engine failures when under Warranty (various Warranty claims accepted)
b) confirm that incorrect lubricants were used that caused a series of major engine failures (various Fleet's fault)
c) confirm that inaction when the lubricant's condition was poor resulted in very expensive engine failures (various Warranty claims denied)
d) obtain reliable maximum OCIs for Fleets
e) select appropriate lubricants for the application (Fleets)
f) change the design of various major component's (engines, diffs, gearboxes)
g) change the formulation of various lubricants and their intended application
h) satisfy various other lubricant/lubrication purposes
As for sudden major "incidents" I have never seen SP UOAs conclusively predict a turbocharger failure, highlight excessive cam lobe wear or cam roller spindle failure, predict-isolate excessive ring wear (except where serious air leaks are present - silicate/iron levels linked). I have never seen excessive cam chain or oil pump wear isolated - the list goes on. The list is long! Trended UOAs may have highlighted a need to monitor conditions more closely in some of these circumstances however, and in certain instances they did!
So IMHO predicting excessive ring pack wear in isolation would be very hard using basic SP UOAs as the sole diagnostic "tool"! If only it was all so easy!!!
Comparing lubricants via wear metal uptakes rates may be possible is certain conditions. These would include same engine family, predictable application and operation and some millions of miles/hour of use - withe each lubricant! Easier waya are used today such as RATT and the likes - this equals wear measurement in controlled conditions and in real time
Incidently my first Paper on UOAs was written in 1975. This was done after spending time in the USA and Europe on a "Technical Industry Fellowship" that embraced working closely with the ATA, Shell, Castrol, GM, Chrysler, Leyland, Cummins, Detroit-Allison, Scania, Volvo, Daimler Benz, ZF and the Trucking Industries of Germany, Sweden and Denmark.
At 70 and retired, I am still learning about lubricants, their application - and about UOAs!
I have no "linkage" to any Oil Company. I once (40 years ago) worked for Caltex-Chevron in a Technical capacity in Scandinavia. I have worked very closely with Shell, Castrol and Mobil as a Commercial user, Road Transport Industry Technical Advisor and as a professional Consultant!
ENDS
Please do not refer to me as an "Expert" or a "Guru" on lubricants and etc - I only Post because I enjoy it and can share my experience and maybe help others. I seek no kudos from this!
