Synthetic Oil = BAD
I took a Mitsubishi mechanic at his word on the head gasket being. The reason behind it all is that my brother's talon has a head gasket problem, developed a crack in it. The mechanic said that if he had used synthetic the entire time it would never have happened. Supposedly, because it get so damn cold up here (-20 Fahrenheit strait up temp during the night happens nearly once a year with no problem and -10 is no big deal for us at all) the oil gets way too thick and causes really high pressures inside the engine that can rupture the head gasket if the oil doesn't run thin enough. Look in your Mitsubishi manual and you'll see that they recommend two different weights depending on the temperature ranges you see. So supposedly by using Mobil 1 everything should be dandy.
I think I may switch to using regular oil during the summer/spring/fall and use synth in the winter and hopefully have the best of all worlds out of it or something.
Later.
I think I may switch to using regular oil during the summer/spring/fall and use synth in the winter and hopefully have the best of all worlds out of it or something.
Later.
Newbie
Joined: Jan 2003
Posts: 47
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From: Chicago, IL
Is everyone missing the point of this entire tirade, or am I off kilter in being under the impression that it was not the oil (or lack thereof) that killed your motor, but the fact that you are asking it to handle, what, 150 more horsepower than it was originally engineered to handle? You have to believe that the engineers at Mistu know at least something about the motor that they designed, right? Things breaking when your 130 hp stock motor is pumping out 250+ hp is to be expected. The majority of the people on this board will never, ever have this problem, running synthetic or not, as the motors are not running on the ragged edge of survival. The funny thing about the loose tolerance in the oil pump that was described is that the tolerance was probably determined to be completely adequate for the normal range of operating conditions that a stock 4G94 will encounter in its life.
I could go on and on about development cycle and numerical models by the motor companies, but that is even more off topic than I currently am. The point is, you (Kontradictions) are pushing the edge of what the product (in this case the 4G94) is currently capable of. While synthetic oil may be deleterious to *your* 4G94 motor in its current state of tune, it does not necessarily translate into being deleterious to *all* 4G94 motors. Posting the information here is invaluable, however, to those looking to build their motor to a similar state of tune.
I could go on and on about development cycle and numerical models by the motor companies, but that is even more off topic than I currently am. The point is, you (Kontradictions) are pushing the edge of what the product (in this case the 4G94) is currently capable of. While synthetic oil may be deleterious to *your* 4G94 motor in its current state of tune, it does not necessarily translate into being deleterious to *all* 4G94 motors. Posting the information here is invaluable, however, to those looking to build their motor to a similar state of tune.
Newbie
Joined: Jan 2003
Posts: 47
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From: Chicago, IL
*note*
Above post may seem to be mean spirited or flaming. It is not. I have the utmost respect for people such as yourself - you are doing the R+D work that major companies spend alot of money on using the limited resources of a single person, and by sharing your pitfalls, you help others to avoid the same situations. I think that message was lost in my ranting.
DannoH
Above post may seem to be mean spirited or flaming. It is not. I have the utmost respect for people such as yourself - you are doing the R+D work that major companies spend alot of money on using the limited resources of a single person, and by sharing your pitfalls, you help others to avoid the same situations. I think that message was lost in my ranting.
DannoH
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Joined: Aug 2002
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From: Raynham, MA
Well seeing as how the thread might be closed and I haven't posted like in 'ages' around here, I've got 2 (or more like 20) cents worth of info for consumption.
Some statements or concepts have been raised in this thread such as synthetic oil is thinner / too thin at high temps versus a dino oil and synthetic oil can't be picked up by the oil pump correctly. Further along in the thread, a few people started to discuss an important aspect of ANY motor oil which is the viscosity rating(s) of the oil assigned to it by the SAE such as 5W-30. Along with the discussion of viscosity, some blanket type information regarding the need or desire to use heavy oil weights such as "I run M1 15W-50", and "you need to go to a "xW-40 weight oil for the turbo" came out to support or mandate the use of a heavy weight synthetic oil.
In order to try and debunk a bit of the synthetic vs conventional oil debate, a discussion or review of viscosity rating(s) is required, but unfortunately the SAE rating of ANY motor oil, be it a conventional (dino), blend, or full synthetic do not completely and accurately describe its viscosity performance. Along with SAE viscosity, another viscosity scale is used to more accurately describe the thickness / flow capabilities of engine oil. This term is "kinematic viscosity." It's basically a controlled test measuring a controlled volume of oil at a specific temperature under the influence of gravity. It produces a number in centistokes or cSt. The lower the cSt, the thinner the oil, the higher the cSt number, the thicker. Kinematic viscosity is usually measured at both 40C and 100C to give a good idea of an oil's cold and hot performance in terms of thickness / viscosity.
Definition of Kinematic Viscosity / Oil Terminology Dictionary
Now, let's look at a chart which compares kinematic viscosity to those assigned by the SAE....
Kinematic versus SAE Viscosity Chart
This chart shows that for a given SAE weight rating such as "30" that there can actually be a range of kinematic viscosities which qualify under that rating. So whether it is conventional or synthetic, you might have a "thinner" or "thicker" oil under both cold or hot conditions. So in order to illustrate this, and to get rid of the constant old wives tale that synthetic oil is too thin when hot versus a pure dino oil, an example needs to be made.
For this example, I'm comparing Mobil1 w/SuperSyn (full synthetic) against Mobil DriveClean (pure dino - not the blend) to see how they stack up against each other in terms of thickness. The SAE 5W-30 grade will be examined. In order to get the necessary technical data, one must go to the mfg's website (in this case Mobil) and pull up the technical specs on each oil to get their respective kinematic viscosities.
The links as follows:
Mobil 1 w/SuperSyn - Technical Data
Mobil DriveClean - Technical Data
When one scrolls down on each of those links and reads the info in the 5W-30 column, the data is as follows:
M1w/SuperSyn.......53.7cSt@40C.......9.7cSt@100C
Mobil DriveClean.....62.0cSt@40C......10.5cSt@100C
So what does this prove? First is that @100 degres celsius, the Mobil1 synthetic is just a tad thinner than the pure dino based Driveclean of the same grade. However, even though the pure synth is thinner, it still falls within the acceptable SAE 30 weight range on the viscosity chart I linked to earlier. It's this very slight reduction in kinematic viscosity which accounts for the typical 1 to 3% gain in fuel economy that most vehicle owners experience if they switch from a typical dino oil to a typical synth oil. More importantly though, there is NO huge difference in terms of synth being thinner than dino to the point that it doesn't lubricate or protect properly versus a pure dino based oil - at least for THIS example of Mobil1 synthetic and Mobil Driveclean. Go back and compare identical grades such as 10W-30, they should once again be very close on the hot or high temperature kinematic viscosities. The point I'm trying to hammer home here is that for ANY oil be it synth or dino, you don't really know which is THICKER or THINNER at operating temps by the SAE weight rating on the bottle...go look at the tech data!
It's this information above that really puts in doubt (for me at least) this whole concept of the 4G94's oil pump not being able to suck up synthetic motor oil and provide proper oil pressure with synthetic oil. If kinematic viscosities are nearly identical, then the flow characteristics / pumping characteristics of the oils should be nearly identical. The friction modifiers and antiwear agents put into synthetic oil don't do anything to modify the compressibility or pumpability of the oil versus a dino. Put simply, all motor oils, be it synthetic, dino, blend, with near identical physical properties (as measured), are fluids which will pump the same. I'd be interested if Kontra actually had the old oil pump from his engine bench tested for flow with a synth oil to see what kind of pressure it could develop. I'd be highly suprised if it didn't function normally.
Could there be some bad oil pumps out there on 4G94's? Sure I guess so, given Mitsu's past with the crankwalk issue, there's always the possibility of some bad parts making their way into the assembly process. But I'd think there'd be more than a very small amount of owners with engine problems already due to oil starvation if a normally working oil pump was somehow incompatible with synthetic motor oil. Synth oil is not some magic in a bottle that somehow turns into water when hot. It's oil that's made from pure gasses and not dino juice. For all intents and purposes, a synth and a conventional oil of the same grade with the same chemical additive package for antiwear and viscosity stabilization to keep the oil in grade will perform nearly identical to each other when NEW. As miles accumulate, the synth oil will usually thin out whereas most conventional oils thicken up since they are much more susceptible to boiloff. A specific test also measures this characteristic of motor oil, and the result is given in a % of the oil that evaporates, it's called the "NOACK Volatility Test", and surely enough it's usually on the Tech Data Sheets of oils which are not AFRAID to show it. The lower the number the better, and the synths usually excel at this compared to the dino oils out there.
I'd highly suggest to any turbo'd 4G94 or Evo owner that they run a used oil analysis or (UOA) at least a few times to see if the oil that the dealer uses or that of your choosing is providing good wear protection over whatever maintenance interval you're following. It provides much useful information in terms of whether the oil stayed in grade and how much detergency protection is left in the oil. In essence you'd know how "whipped" the oil was after use. More specifically, you'd see if the fuel dillution is high - meaning the degree of unburned fuel that is absorbed by the oil from blow by. This tends to kill the lubricative properties of any oil, synth or dino, real quick. The fact that there's now a turbo pumping some boost means that blow by gasses are probably increased, putting more combustion byproducts into the oil, making it wear out sooner. If Kontra could have a UOA done on the oil when the engine failed, this would have the potentional to be an eye opener.
A factor which was mentioned which could be playing into this is the brand / type of oil filter being used on the motor. Oil filters are all different animals in terms of their resistance to flow and pressure drop across the filter element, but that's a different story for a different day....
In any event I hope you take away something from this contribution...namely that synthetic oil is nothing mysterious in terms of its properties and that you can't necessarily judge an oil bottle by its cover.
Over and out....
DF
Some statements or concepts have been raised in this thread such as synthetic oil is thinner / too thin at high temps versus a dino oil and synthetic oil can't be picked up by the oil pump correctly. Further along in the thread, a few people started to discuss an important aspect of ANY motor oil which is the viscosity rating(s) of the oil assigned to it by the SAE such as 5W-30. Along with the discussion of viscosity, some blanket type information regarding the need or desire to use heavy oil weights such as "I run M1 15W-50", and "you need to go to a "xW-40 weight oil for the turbo" came out to support or mandate the use of a heavy weight synthetic oil.
In order to try and debunk a bit of the synthetic vs conventional oil debate, a discussion or review of viscosity rating(s) is required, but unfortunately the SAE rating of ANY motor oil, be it a conventional (dino), blend, or full synthetic do not completely and accurately describe its viscosity performance. Along with SAE viscosity, another viscosity scale is used to more accurately describe the thickness / flow capabilities of engine oil. This term is "kinematic viscosity." It's basically a controlled test measuring a controlled volume of oil at a specific temperature under the influence of gravity. It produces a number in centistokes or cSt. The lower the cSt, the thinner the oil, the higher the cSt number, the thicker. Kinematic viscosity is usually measured at both 40C and 100C to give a good idea of an oil's cold and hot performance in terms of thickness / viscosity.
Definition of Kinematic Viscosity / Oil Terminology Dictionary
Now, let's look at a chart which compares kinematic viscosity to those assigned by the SAE....
Kinematic versus SAE Viscosity Chart
This chart shows that for a given SAE weight rating such as "30" that there can actually be a range of kinematic viscosities which qualify under that rating. So whether it is conventional or synthetic, you might have a "thinner" or "thicker" oil under both cold or hot conditions. So in order to illustrate this, and to get rid of the constant old wives tale that synthetic oil is too thin when hot versus a pure dino oil, an example needs to be made.
For this example, I'm comparing Mobil1 w/SuperSyn (full synthetic) against Mobil DriveClean (pure dino - not the blend) to see how they stack up against each other in terms of thickness. The SAE 5W-30 grade will be examined. In order to get the necessary technical data, one must go to the mfg's website (in this case Mobil) and pull up the technical specs on each oil to get their respective kinematic viscosities.
The links as follows:
Mobil 1 w/SuperSyn - Technical Data
Mobil DriveClean - Technical Data
When one scrolls down on each of those links and reads the info in the 5W-30 column, the data is as follows:
M1w/SuperSyn.......53.7cSt@40C.......9.7cSt@100C
Mobil DriveClean.....62.0cSt@40C......10.5cSt@100C
So what does this prove? First is that @100 degres celsius, the Mobil1 synthetic is just a tad thinner than the pure dino based Driveclean of the same grade. However, even though the pure synth is thinner, it still falls within the acceptable SAE 30 weight range on the viscosity chart I linked to earlier. It's this very slight reduction in kinematic viscosity which accounts for the typical 1 to 3% gain in fuel economy that most vehicle owners experience if they switch from a typical dino oil to a typical synth oil. More importantly though, there is NO huge difference in terms of synth being thinner than dino to the point that it doesn't lubricate or protect properly versus a pure dino based oil - at least for THIS example of Mobil1 synthetic and Mobil Driveclean. Go back and compare identical grades such as 10W-30, they should once again be very close on the hot or high temperature kinematic viscosities. The point I'm trying to hammer home here is that for ANY oil be it synth or dino, you don't really know which is THICKER or THINNER at operating temps by the SAE weight rating on the bottle...go look at the tech data!
It's this information above that really puts in doubt (for me at least) this whole concept of the 4G94's oil pump not being able to suck up synthetic motor oil and provide proper oil pressure with synthetic oil. If kinematic viscosities are nearly identical, then the flow characteristics / pumping characteristics of the oils should be nearly identical. The friction modifiers and antiwear agents put into synthetic oil don't do anything to modify the compressibility or pumpability of the oil versus a dino. Put simply, all motor oils, be it synthetic, dino, blend, with near identical physical properties (as measured), are fluids which will pump the same. I'd be interested if Kontra actually had the old oil pump from his engine bench tested for flow with a synth oil to see what kind of pressure it could develop. I'd be highly suprised if it didn't function normally.
Could there be some bad oil pumps out there on 4G94's? Sure I guess so, given Mitsu's past with the crankwalk issue, there's always the possibility of some bad parts making their way into the assembly process. But I'd think there'd be more than a very small amount of owners with engine problems already due to oil starvation if a normally working oil pump was somehow incompatible with synthetic motor oil. Synth oil is not some magic in a bottle that somehow turns into water when hot. It's oil that's made from pure gasses and not dino juice. For all intents and purposes, a synth and a conventional oil of the same grade with the same chemical additive package for antiwear and viscosity stabilization to keep the oil in grade will perform nearly identical to each other when NEW. As miles accumulate, the synth oil will usually thin out whereas most conventional oils thicken up since they are much more susceptible to boiloff. A specific test also measures this characteristic of motor oil, and the result is given in a % of the oil that evaporates, it's called the "NOACK Volatility Test", and surely enough it's usually on the Tech Data Sheets of oils which are not AFRAID to show it. The lower the number the better, and the synths usually excel at this compared to the dino oils out there.
I'd highly suggest to any turbo'd 4G94 or Evo owner that they run a used oil analysis or (UOA) at least a few times to see if the oil that the dealer uses or that of your choosing is providing good wear protection over whatever maintenance interval you're following. It provides much useful information in terms of whether the oil stayed in grade and how much detergency protection is left in the oil. In essence you'd know how "whipped" the oil was after use. More specifically, you'd see if the fuel dillution is high - meaning the degree of unburned fuel that is absorbed by the oil from blow by. This tends to kill the lubricative properties of any oil, synth or dino, real quick. The fact that there's now a turbo pumping some boost means that blow by gasses are probably increased, putting more combustion byproducts into the oil, making it wear out sooner. If Kontra could have a UOA done on the oil when the engine failed, this would have the potentional to be an eye opener.
A factor which was mentioned which could be playing into this is the brand / type of oil filter being used on the motor. Oil filters are all different animals in terms of their resistance to flow and pressure drop across the filter element, but that's a different story for a different day....
In any event I hope you take away something from this contribution...namely that synthetic oil is nothing mysterious in terms of its properties and that you can't necessarily judge an oil bottle by its cover.
Over and out....
DF
Last edited by diesel_fan; Jun 4, 2003 at 10:29 PM.
Holy crap.... my jaw is on the floor, for someone to know that much about oil blows my mind and is DAMN cool. Pardon me while I bow down to you man!
I also believe that just because someone's engine had oil problems and they ran synthetic it suddenly becomes a synthetic oil problem as far as the dealer is concerned and they neglect to remember the other cases that were organic based.
I think diesel_fan clears up the technical aspects of this issue... in a BIG *** and impressive way.
I also believe that just because someone's engine had oil problems and they ran synthetic it suddenly becomes a synthetic oil problem as far as the dealer is concerned and they neglect to remember the other cases that were organic based.
I think diesel_fan clears up the technical aspects of this issue... in a BIG *** and impressive way.
Evolving Member
Joined: Aug 2002
Posts: 158
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From: Raynham, MA
I spend a lot of time reading on BOBISTHEOILGUY.COM. It's a website where oldtimers spend a LOT of time debating the characteristics of oil, comparing oil analysis results, debating filter types, doing filter tests..... I wish I were an expert but I cannot claim to be one...I just do a LOT of reading on the concepts 
DF
DF
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From: Southern California
well people looks like my car will be back up and running next week!
I finally decided to go with Rob at RRM and get some pistons from him! Thanks Rob!
I had to get a new oil pump, oil pick up line, crank, crank bearings, rods, pistons, rod bearings, and new oil of course!
What fun it has been trying to get this to work out...oh well hopefully all will be fine now!
I finally decided to go with Rob at RRM and get some pistons from him! Thanks Rob!
I had to get a new oil pump, oil pick up line, crank, crank bearings, rods, pistons, rod bearings, and new oil of course!
What fun it has been trying to get this to work out...oh well hopefully all will be fine now!
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From: Pico Rivera
I think details are everything when oil pump is marginal. Synthetic might be ok in certain cliamtes and in the proper weight you choose. Turbos don't throw rod bearings oil related issues do!
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Originally posted by BostonLancer
I have the question of the million bucks!
So which oil are u going to use from now on?
I have the question of the million bucks!
So which oil are u going to use from now on?
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Originally posted by raul
I think details are everything when oil pump is marginal. Synthetic might be ok in certain cliamtes and in the proper weight you choose. Turbos don't throw rod bearings oil related issues do!
I think details are everything when oil pump is marginal. Synthetic might be ok in certain cliamtes and in the proper weight you choose. Turbos don't throw rod bearings oil related issues do!
Evolving Member
Joined: Aug 2002
Posts: 158
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From: Raynham, MA
A consumer must select the proper weight for climate conditions and engine application, be it synthetic or conventional or blend.
The pump may indeed be the marginal link here in terms of its flow reserve since an aftermarket turbo's oil supply line is now t'd into the lube circuit past the filter. If the pump cannot make up the flow "used" by the turbo's supply line, the oil pressure at the mains will be less than before. At idle, this may be critical since the oil pump is turning at its minimum speed, meaning there is minimal flow reserve available.
I'd actually be real interested for David Thomas of RPW to chime in here with some of his input in terms of the stock pump's oiling capacity / flow.
20W-50 Mobil1 is excellent, especially if you're contemplating racing or track use since it's pretty thick. Certainly not suitable for up north usage though or colder climates.
Good luck with it....
DF
The pump may indeed be the marginal link here in terms of its flow reserve since an aftermarket turbo's oil supply line is now t'd into the lube circuit past the filter. If the pump cannot make up the flow "used" by the turbo's supply line, the oil pressure at the mains will be less than before. At idle, this may be critical since the oil pump is turning at its minimum speed, meaning there is minimal flow reserve available.
I'd actually be real interested for David Thomas of RPW to chime in here with some of his input in terms of the stock pump's oiling capacity / flow.
20W-50 Mobil1 is excellent, especially if you're contemplating racing or track use since it's pretty thick. Certainly not suitable for up north usage though or colder climates.
Good luck with it....
DF
Great kontra... I use the valvoline VR-1 racing formula 20/50! Is there a difference not really but the VR-1 is supposedly designed for race enthusiasts like us who also use the car for daily driving. As for the turbo sucking oil pressure it is very minimal considering the tiny line being used... however could be a possibility to support the "turbo is at fault" theory. Explain to me why there are many cases of NA guys running synthetic with low oil pressure lights and some damaging motor. Explain why mitsubishi won't recommend synthetic with this motor. Please... Anybody!