Age old Question/Argument

[TobyB]

I use oil that comes in bottles.
I figure the stuff in cans has gotten old by now.

...just to add another point to an already pointy threaddy.

t

[packratbimmer]

After seeing a multitude of wiped out cams and rockers on M20 cars, I say bring on any/all discussion about the correct oil to use, especially those of us in cold climates.

[shoshottz]

& hell climates.


shottz.

[dnguyen1963]

based on what data ? i wouldnt have hesitation in using 10W-30 in winter here and we get mild winter where min is 35F. the oil temp doesnt really exceed 180F so the voscosity is probably the same as a 10W-50 in summer at 200F. im talking just normal street driving. not talking about getting temps upto 110C+ on the track

The valves clack like crazy when running 5w30. I saw shiny metal flakes in the oil after just 1 day of using 5w30. That is proof enough for me.

[digger]

the increase or decrease in the clack clack of valves is not a measure of the effectiveness or lack of effectiveness of an oil. i seriously doubt a change in viscosity that would suddenly produce flakes of metal within 1 day in a normal driven vehicle unless the oil was lacking in some other area.

the only "special" feature of an m20 that requires specific oil requirements is the cam-rocker valvetrain which requires a minimum amount of ZDDP and even then its not a modified SBC/BBC with extreme spring pressures so the amount you need is not as critical if you have a modified valvetrain.

the rod and main bearings used between the m20 and later M5x engines and the like is basically identical. XXW-30 oils tend to be the biggest sufferer in reduced zinc and so forth so if you choose the wrong oil with slighty too loose rocker clearances then the cam and rocker could easily wipe but this is not really to do with viscosity of a 30 weight oil its the additive package or lack of

[dnguyen1963]

the increase or decrease in the clack clack of valves is not a measure of the effectiveness or lack of effectiveness of an oil. i seriously doubt a change in viscosity that would suddenly produce flakes of metal within 1 day in a normal driven vehicle unless the oil was lacking in some other area.

the only "special" feature of an m20 that requires specific oil requirements is the cam-rocker valvetrain which requires a minimum amount of ZDDP and even then its not a modified SBC/BBC with extreme spring pressures so the amount you need is not as critical if you have a modified valvetrain.

the rod and main bearings used between the m20 and later M5x engines and the like is basically identical. XXW-30 oils tend to be the biggest sufferer in reduced zinc and so forth so if you choose the wrong oil with slighty too loose rocker clearances then the cam and rocker could easily wipe but this is not really to do with viscosity of a 30 weight oil its the additive package or lack of

I won't argue with you, but empirical evidence cannot be ignored sometimes. The slapping in the cam rockers stopped completely as soon as the engine saw 15w40. Who knows where the shiny flakes came from, but why would anyone take a chance? I'm not saying that 5w30 will kill your engine, but I have not seen anything good coming from the use of that oil.

[packratbimmer]

Thanks digger - that's the kind of info I have been looking for... especially bit about the main bearing composition.

Wish I could afford a rollerized valve train!

[estoguy]

I went synthetic after a few months of owning my E30, I went with the Castrol Edge 5w50, based on some research - I wanted a heavier synthetic with a good ZDDP package. Haven't had any issues since, and my engine is running strong. I've put about 200K km on it since switching to it. Have over 450K now.

[digger]

I won't argue with you, but empirical evidence cannot be ignored sometimes. The slapping in the cam rockers stopped completely as soon as the engine saw 15w40. Who knows where the shiny flakes came from, but why would anyone take a chance? I'm not saying that 5w30 will kill your engine, but I have not seen anything good coming from the use of that oil.

there are of course crap oils so you cant say all 5W-30 oils are bad based one data point.

[shoshottz]

where are you located estoguy?


shottz.

[digger]

Thanks digger - that's the kind of info I have been looking for... especially bit about the main bearing composition.

Wish I could afford a rollerized valve train!

Yeah, The rod bearings are the same exact P/N and people use 24V cranks and rods in the M20 every day using OEM bearings on non-resized crank journals. The mains basically never wear out unless you lose supply of oil or get crap in the oil, poor assembly. People use thin oils on the M52/S52 etc in cold climates so the mains and rods don’t seem to need thick oil unless the oil is very hot. that is my observation atleast it might be simplistic perspective though

I wouldn’t go experimenting to much on a stock engine just run a decent oil and be done with it there is little to be gained for the most part, but i do recommend finding an oil that is not too thick when its cold as that is where most wear occurs. pretty much all oils are hopeless when cold so something less hopeless is preferred

[dnguyen1963]

there are of course crap oils so you cant say all 5W-30 oils are bad based one data point.

Are you using 5w30 in your engine? You seem to be defending the use of this oil strongly. If not, why don't you put it in your engine and run it for awhile to see how happy you will be. There are many other users here that are strongly against the use of 5w30...so it is not based on a single data point.

[digger]

Are you using 5w30 in your engine? You seem to be defending the use of this oil strongly. If not, why don't you put it in your engine and run it for awhile to see how happy you will be. There are many other users here that are strongly against the use of 5w30...so it is not based on a single data point.

it is a single data point where is all the data showing failed engines with a slightly lower viscosity? people may not recommend it but how is anyone elses opinon more valid than someone elses when there isnt any data to back it up. mine is just as valid or invalid an opinion when it isn't backed up by scientific testing of long term wear tests.

no im using 10W-40 but on the back end of the winter so no use changin it now to run it for 2 months before it starts getting too hot again. we dont get cold winters here anyway 35F is the min and max on the day could be 80F. im not talking about 30 weight in middle of summer

i may use it next winter though depending on new build specs, the new engine will have enough differences that i need to speak to some experts. It wouldn't be 5w-30 it would likely be 10W-30 as i can get that with same additives as what i can get with 10W-40 and 10W-50. based on running 10W-40 oil temps and pressures i would have chosen 10W-30 if my time again in same scenarios. the viscosity at operating temp of the 30 is the same as a 50 that i use in summer. with same brand and classifcation of oil i cant see how suddenly lower viscosity causes the sky to fall down. in your case something else was at play if you dont know where the flakes came from you dont know what happened or why yet you blame viscosity

if you had oil analysis trends before and after then you might have more weight to your argument

[staysideways]

throw some seafoam in there & drive a couple miles b4 oil change... should clean out the ceankcase supremely.


shottz.

I just drain roughly 1 quart of motor oil and top it it off with roughly give or take quart of ATF WHEN THE ENGINES HOT. drive it around like 5-10 minutes and when I get home I turn off the car and drain the oil asap you don't want that to sit in the pan. It has cleaned my neglected little m20 from super black/brown to a golden yellow (in the head where the valve train lives). It's a slow process but definitely worth it. For cheaper than seafoam.


Sent from my iPhone using Tapatalk

[dnguyen1963]

it is a single data point where is all the data showing failed engines with a slightly lower viscosity? people may not recommend it but how is anyone elses opinon more valid than someone elses when there isnt any data to back it up. mine is just as valid or invalid an opinion when it isn't backed up by scientific testing of long term wear tests.

no im using 10W-40 but on the back end of the winter so no use changin it now to run it for 2 months before it starts getting too hot again. we dont get cold winters here anyway 35F is the min and max on the day could be 80F. im not talking about 30 weight in middle of summer

i may use it next winter though depending on new build specs, the new engine will have enough differences that i need to speak to some experts. It wouldn't be 5w-30 it would likely be 10W-30 as i can get that with same additives as what i can get with 10W-40 and 10W-50. based on running 10W-40 oil temps and pressures i would have chosen 10W-30 if my time again in same scenarios. the viscosity at operating temp of the 30 is the same as a 50 that i use in summer. with same brand and classifcation of oil i cant see how suddenly lower viscosity causes the sky to fall down. in your case something else was at play if you dont know where the flakes came from you dont know what happened or why yet you blame viscosity

if you had oil analysis trends before and after then you might have more weight to your argument

This is not a scientific argument. I'm a scientist so I understand your point. None of us has funding or resource to carry out a scientific analysis of the situation. It is about risks. Although, there is not enough scientific facts about 5w30 oil hurting the engine there are plenty of noises from other users about not using this oil. Is it worth the risk? My point is no...stay with the tried and true 15w40 for cold and 20w50 for warm climate. That's all. Regarding the flakes, I don't know where it came from. All I know is that I observed the flakes when I switched over to 5w30. It was not present in the next 15w40 oil change. Again, is it worth the risk of using 5w30 even if I do not know the cause of the flakes? The answer is an obvious NO. It could be that the thinner oil was washing out some 20+ yrs of deposits...who knows.