Diesel Oil "Too Good" for Non-diesel Use
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Another #@$%!!
there's never such a thing called too-clean that it would loose compression. Anyone who initiated such claims are either spreading unproven rumours on the internet, or he is an absolute moron (not mechnics to being with for sure).
Yes, I may sound like a jerk but being a mechanic, there are 2 things I particularly hate (with a passion): (a) guys who insisted that they know everything about cars and internal combustion engines and yet cannot even make sense with fundamental operation of such engines and/or (b) guys who refused to take in sage advise from experts in the automotive field and decipher the valuable information from some other useless information.
Q.
there's never such a thing called too-clean that it would loose compression. Anyone who initiated such claims are either spreading unproven rumours on the internet, or he is an absolute moron (not mechnics to being with for sure).
Yes, I may sound like a jerk but being a mechanic, there are 2 things I particularly hate (with a passion): (a) guys who insisted that they know everything about cars and internal combustion engines and yet cannot even make sense with fundamental operation of such engines and/or (b) guys who refused to take in sage advise from experts in the automotive field and decipher the valuable information from some other useless information.
Q.
I would say that had an individual been using a lower detergent oil for a long period of time and going to long on intervals , then switching to a series 3 type diesel package with its much higher levels of Metallo organic compounds (detergent additives) a cleaning of the engine could take place and expose previously undisturbed deposits. which could then effect compression levels. But thats just a guess
The opposite should be true under all operating conditions:
If an engine looses compression due to oil related deposits on the oil control ring grooves, piston compression rings grooves, etc. and IF the introduction of high detergency motor oil does clean up the oil control rings grooves and galleys as well as compression ring grooves, proper compression shall be observed as a consquence.
Regrettably, this cannot be hold true in real-life situation for (a)deposits formed in oil control ring groove and galleys are difficult to achieve reasonable cleansing effect by means of using motor oil lubricant with detergent (detergent in oil is primarily responsible in maintaining cleanliness, not to clean something dirty to begin with), and (b) deposits formed in various compression ring grooves are almost impossible to clean with motor oil itself, given the fact that the amount of oil reaching these grooves are minute and "controlled" and also the fact that these deposits are caused by thermal breakdown and oil reaching these deposits are usually too little to get a large amount of work done.
I have pretty decent luck with AutoRx cleaning up oil stuck oil control rings but if the oil burning is excessive and/or excessively stucked/jammed compression rings, nothing, I mean absolutely nada, can clean out these deposits unless you take apart your engine and manually scrape off those deposits.
Forget about high detergency motor oil such as HDEO. It's not meant for cleaning up sludged up engines or engines that have suffered from long-term neglect (with stuck oil control rings, compression rings, etc.).
If an engine looses compression due to oil related deposits on the oil control ring grooves, piston compression rings grooves, etc. and IF the introduction of high detergency motor oil does clean up the oil control rings grooves and galleys as well as compression ring grooves, proper compression shall be observed as a consquence.
Regrettably, this cannot be hold true in real-life situation for (a)deposits formed in oil control ring groove and galleys are difficult to achieve reasonable cleansing effect by means of using motor oil lubricant with detergent (detergent in oil is primarily responsible in maintaining cleanliness, not to clean something dirty to begin with), and (b) deposits formed in various compression ring grooves are almost impossible to clean with motor oil itself, given the fact that the amount of oil reaching these grooves are minute and "controlled" and also the fact that these deposits are caused by thermal breakdown and oil reaching these deposits are usually too little to get a large amount of work done.
I have pretty decent luck with AutoRx cleaning up oil stuck oil control rings but if the oil burning is excessive and/or excessively stucked/jammed compression rings, nothing, I mean absolutely nada, can clean out these deposits unless you take apart your engine and manually scrape off those deposits.
Forget about high detergency motor oil such as HDEO. It's not meant for cleaning up sludged up engines or engines that have suffered from long-term neglect (with stuck oil control rings, compression rings, etc.).
I've had a standing request on here for someone to show me photo evidence of significant cleaning by an HDEO in their car. Only one person has even tried.
It sure didn't work in my car. Yet I know some veteran TOP NOTCH mechanics who think one short run of Rotella is going to just break everything loose!
It sure didn't work in my car. Yet I know some veteran TOP NOTCH mechanics who think one short run of Rotella is going to just break everything loose!
What might be possible is that rather than losing compression due to piston ring issues, if there has been very much oil getting past the valve guides and ending up as deposits on the backside of the intake valves, it might be possible that the introduction of a motor oil (or additive for such) that might be oriented toward dissolving internal engine deposit accumulations could, with sustained freeway driving, cause these accumulations on the intake valves to fracture, move into the valve seat area, and prevent the intake valve from sealing properly, resulting in a compression loss (and the need for a valve job to get things cleaned up again).
I mention this as such a set of cylinder heads came into my machine shop operative's shop back in the 1980s. A guy and his family were transferring down here from up north. On the way down, after a good number of freeway-speed miles (at probably about 2600-2800 rpm cruise, pulling a medium-size U-Haul trailer), the engine started running rough and missing at highway speeds. When the heads were disassembled, there were accumulations on all of the backsides of the intake valves. It was obvious where some pieces had broken off from what was still there. Once the hard deposits got onto the valve seats, the valves could not firmly and effectively seat any more.
I concur that detergents in motor oil are there to keep things clean rather than do radical cleaning themselves. But I also recall that some synthetic oil formulations will clean things due to the type of oil they are rather than a specific detergent additive pack?
In any case, what is quoted from carbibles.com would be somewhat suspect (as to its accuracy in this case) to me.
Just some thoughts,
CBODY67
I mention this as such a set of cylinder heads came into my machine shop operative's shop back in the 1980s. A guy and his family were transferring down here from up north. On the way down, after a good number of freeway-speed miles (at probably about 2600-2800 rpm cruise, pulling a medium-size U-Haul trailer), the engine started running rough and missing at highway speeds. When the heads were disassembled, there were accumulations on all of the backsides of the intake valves. It was obvious where some pieces had broken off from what was still there. Once the hard deposits got onto the valve seats, the valves could not firmly and effectively seat any more.
I concur that detergents in motor oil are there to keep things clean rather than do radical cleaning themselves. But I also recall that some synthetic oil formulations will clean things due to the type of oil they are rather than a specific detergent additive pack?
In any case, what is quoted from carbibles.com would be somewhat suspect (as to its accuracy in this case) to me.
Just some thoughts,
CBODY67
Good observations CBODY67-
Just a couple of quick observations here:
(1)granted that there is no motor oil getting past valve guides and valve stem seals to form carboneacious-like deposits on the back of the intake valves
(2)there is no additional/unnecessary gasoline remained on the back of intake valves (intake manifold) caused by improperly adjusted carb or leaky fuel injectors
(3) PCV system is in good working order, and no excessive piston ring blowby is observed
and
(d) use of high quality/high detergency gasoline (which helps in controlling the formation of gasoline related deposits on the back of intake valves)
, there shall never be such problems of dlslodging of a carbon particles from the intake valve section, stuck on the valve seat causing valve to seat burnout.
I would be suspicious of the fact that the engine is not in good operational condition (meaning that at it failed to meet at least 1 or more of the aforementioned points) to begin with, or with consistent user neglect (poor gasoline with poor detergency in controlling deposits (which coincidentally, is a common issues with US pump grade gasoline in the 70s well into the late 80s,and many mechanically FI cars from VW rabbit, etc. where injector spray pattern becomes a serious issue due to low/lack of detergency in pump gas causing pintle/orifice deposits). Also: improperly adjusted carb which has a tendency in introducing far more raw/rich gasoline into the intake valves than necessary will cause heat-coking on the back of the valve, causing carbon deposits.
Nowadays, with better quality control in gasoline grades, precision FI controls and well-exercised engine designs and orientation, most of the cars on the road these days aren't suffering as much carbon deposits on the back of intake valves like they used to some 30+yrs ago. That being said, however, operator shall never neglect the importance of basic maintenance such as tuneups, spark plug replacements, PCV valve servicing, conservative OCI, etc.
my observations. YMMV.
Just a couple of quick observations here:
(1)granted that there is no motor oil getting past valve guides and valve stem seals to form carboneacious-like deposits on the back of the intake valves
(2)there is no additional/unnecessary gasoline remained on the back of intake valves (intake manifold) caused by improperly adjusted carb or leaky fuel injectors
(3) PCV system is in good working order, and no excessive piston ring blowby is observed
and
(d) use of high quality/high detergency gasoline (which helps in controlling the formation of gasoline related deposits on the back of intake valves)
, there shall never be such problems of dlslodging of a carbon particles from the intake valve section, stuck on the valve seat causing valve to seat burnout.
I would be suspicious of the fact that the engine is not in good operational condition (meaning that at it failed to meet at least 1 or more of the aforementioned points) to begin with, or with consistent user neglect (poor gasoline with poor detergency in controlling deposits (which coincidentally, is a common issues with US pump grade gasoline in the 70s well into the late 80s,and many mechanically FI cars from VW rabbit, etc. where injector spray pattern becomes a serious issue due to low/lack of detergency in pump gas causing pintle/orifice deposits). Also: improperly adjusted carb which has a tendency in introducing far more raw/rich gasoline into the intake valves than necessary will cause heat-coking on the back of the valve, causing carbon deposits.
Nowadays, with better quality control in gasoline grades, precision FI controls and well-exercised engine designs and orientation, most of the cars on the road these days aren't suffering as much carbon deposits on the back of intake valves like they used to some 30+yrs ago. That being said, however, operator shall never neglect the importance of basic maintenance such as tuneups, spark plug replacements, PCV valve servicing, conservative OCI, etc.
my observations. YMMV.
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