It does eem like that, I am just curious which would be best, I am still learning 10w-40 or 5w40?
If thereâs knocking, Iâd go with the 10W40. And start saving my spare change.
Unless I am completely wrong you are a young person and this vehicle was your parents. If that is correct you need to get them involved in this. If the oil pressure is really that bad it needs to be taken care of before you send a piston rod through the side of the block.
The vehicle still has lots of life left, my dad never really liked the truck, Ive put 500 in that he never would because he always thought it would break down and it has yet to. This chevy has never let me down. I just know the oil pressure is a little scary being that low at a red light when its warmed up
Three letters: STP
;-]
and when it starts up its just barely over 40
I agree that you probably have worn bearings. It is likely that the oil changes werenât taken care of when they should have been for it to be this bad. Modern engines will go a LONG TIME before needing this type of work.
If you want to go to 5W40, I suggest the Rotella T6 full synthetic. This is an exceptional oil. I run it in all of my outdoor power equipment which I run quite hard. A couple of my riding mowers put up with abuse that nothing else would. I run them wide open (governor bypassed) cutting what are essentially hay fields for hours on end. I change the oil and filter once a year and the oil doesnât appear dirty or broken down. These engines also came to me as slight oil burners with nasty lifter ticks (they are Kohler Commands with hydraulic lifters) and now I canât see any drop on the stick between changes and the lifters sound normal.
Going up to a 40W might help with the pressure at operating temps. You might consider a 10W40 if that doesnât work. I would say you might try a 15W50 if that doesnât work but then you might start introducing other problems. Again, this engine is probably on its last legs. You are only prolonging its life a little.
The 0W40 Mobil 1 European is also a great oil but it tends to be more like a 5W30, so on the thin end of the range. This oil was mainly done so that anti-wear additives could be included for European cars and not to create a new weight. These anti-wear additives have been removed from most US oils as they tend to foul emissions systems over time.
There is something to be said for âsmall movesâ when trying different things.
Going from 5w30 to 10w-40 means two âmovesâ: 5 to 10 at cold temps and 30 to 40 at operating temps.
Going to 5w40 means only the second âmoveâ. Going to 0w40 would again be two âmovesâ.
And to be fair, 5w40 is a âfully syntheticâ oil, so if your car has never used fully synthetic before, that can also be one âmoveâ. (Although there are pages and pages of internet words about whether switching between fully syn, semi-syn, and mineral oil makes a difference)
Last, Iâm pretty sure there are cars out there with 5w40 as either an optional or recommended weight to use. Mobil and Castrol both make it.
Have you replaced the oil pressure sending unit? these fail much more often than engines. Unless the engine has been neglected it shouldnât need two rebuilds in 235,000 miles.
If you live in a colder climate stick with the 5w30. The number before W is the thickness of oil when it cold it will operate like 10 or 5 weight in your example. Once the engine is up to operating tempature it will run at 30 weight. It is important to follow your owners book. It will usally tell you what is the heaviest weight you can run. It is also important that you are using full synthetic oil and stay with that. Do not mix a oils ie 2qt this and 1qt that your not a mixing a cosmo for your car or truck lol. With over 200k miles you can use a high mileage oil. If you do go this route itâs fine but you must continue using high mileage oil you can not switch back after you start using it!! The reason for this is they put special additives in these oils to make your valve seals and rings and such expand. So that it forms a better seal for these parts. If you stop using it they will shrink back down and then you will burn oil and or start having oil leaks. My sugestion for you would be if your in a really cold envorment with winters and such go with a 5w or even 0w. Check your book and see what is the correct weight for your case and use it. I live in the desert so my car has in it now a 0w20. When my next oil change comes up I will have them put a 5w30 in it for better protection and better and stable oil pressure.
âI live in the desert so I use 0-20â? Desert or Alaska. Use what the manual says to use. I am going to change to 5-30 next time even though manual says use 0-20? Itâs your car. If your car is specâd for 20w, it will produce XX oil pressure. If you use 30w, it will produce higher pressure. Which means lower oil flow. Not what engineers intended
The same committee that determined there was no need to service an automatic for the life of the car also determined that 0W20 was the ideal oil.
Thatâs not true Cavell you donât know what Iâm runing or what my car can handle. You would see if you re read the post one point I made was to make sure you follow your book for your vehicle. I have no use for 0w20 in my car in the hight temps I live in, rather I need higher protection from wear than protection from cold. The reason they put 0w20 in is for cold start protection and fuel economy. It says so right in my book. It also say I can go up to a 40 race oil if I did that. My car is a real high compression and high rev. I rather have a little more protection and stablize my oil pressure than one more mpg. Once your engine and oil is at operating temp you will lose protection and stable pressure if the engine is put under load ie towing, high rev or race conditions. Itâs important to follow your book for both conditions and driving styles. The OP is looking to change the weight or go to a high mileage oil. For that with the mileage he gave us he needs to follow his book for the correct weight/conditions/driving style for his application. But it is vary important that if he dose go over to a High mileage oil he stays with it as I mentioned in my other post. Your close it you go to a higher weight during load conditions your will have more protection from wear it will also help with stable pressures. In the conditions a lighter oil will flow easier and faster(at low temps at non load conditions) that is why you have a lower weight during cold weather and start up so you do not suffer wear. You will lose protection under load and above standard engine and oil temps from lighter oil. This is why an oil cooler will help to mantain pressure and protection because it keeps the oil at optimum tempature so it will flow properly for the weight. Thinner oil will drop pressure at higher temps and protection.
Itâs a common weight for European cars. My momâs CLK 430 specs it. Though for the past 5 oil changes Iâve used M1 0W-40. As itâs readily available.
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From your ownerâs manual
âRecommended viscosity: SAE 0W-20
SAE 0W-20 is the best choice for
good fuel economy and good
starting in cold weather.
If SAE 0W-20 is not available,
SAE 5W-20 oil may be used.
However, it must be replaced
with SAE 0W-20 at the next oil
change.â
It seems that Toyota/Subaru is pretty explicit in what oil they recommend. I donât doubt itâs mainly for CAFE numbers. But straight 40 weight? Nope.
Your right they are specific. Above is the jdm OM from Subaru is the designers and engineers for this engine and your right not a straight 40w itâs a 5w40 professional for race use. I have friends and family that works for subi/toyota in USA and japan. I got the OM right from Subaru in Japanese. You will find as I did the only reason both Toyota and Subaru have the same thing in the printed OM in au,na,sa,eu for the twins. 0w20 is for the whole fuel economy and cold start. Yea it is cafe numbers. You will find that almost all new Toyota including trucks, camery, im, they are all using 0w20 in most of there cars for cafe#. Subaru engineered it up to 5w40 weight professional race oil.
factory service manual for my 2012 Altima lists 5w30 and 10w30 are the only two options for USA/Canada
for Mexico they add everything from 10W40 to 20W50 as acceptable options
I highly doubt USA/Canada receive a very special engine type, it looks more like CAFE compliance requirement
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I live in Mexico. They do list 20W-50 oil as an option in cars sold here. That isnât because itâs a good idea, but because everyone here is convinced anything lighter will instantly destroy your motor. So, to sell cars they have to let them think it is an option.
Several years ago, I wanted a quart of 10W-30 oil to carry in the car, just in case. I walked into an automotive store downtown and when I asked for 10W-30, this smart aleck punk snarled at me, âIt will destroy your motor.â
My car at that time had close to 200,000 miles with 10W-30, and as you all know, was not destroyed. But, they all believe it, so much so that many stores only stock 20W-50. Once even Autozone had nothing else.
A doctor once tried to tell me this was because the car companies made motors and the bad ones are sold in Mexico, while the good ones go to the USA. More likely, they sell the same motors and the 20W-50 oil moves them to the bad class.
Are you telling me that if you buy a brand new 2017 or 2018 model year car in Mexico . . . perhaps one with dual variable valve timing . . . the ownerâs manual will list 20w50 as an acceptable engine oil to use?
Youâve told that story before, and I enjoy hearing it every time 
Thereâs only 2 scenarios in which I would use 20w50 in such a vehicle
-
Somebody convinced me that to do otherwise would put my physical health in jeopardy. There would have to be a strong implication that they would be the one to cause me direct physical harm
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The engine was several quarts low on oil . . . for whatever reason . . . and 20w50 was the only engine oil available in the area
Even if you know NOTHING about automobiles, this is NOT the first thing that should come to mind if you need to top up your crankcase on a gasoline powered dohc dual variable valve timing model year 2018 sedan. I wouldnât even have dreamt of using that on my former 1995 Corolla
Just looking at the packaging SHOULD make you think twice, unless youâre actually topping up a vehicle that looks like the ones pictured
Lol bad motors go one place and good go to the other sorry that was just so funny. In my case the engines are all the same the only differences are air intake manafold and ecu programming between the toy/subi that goes to au eu ect. Most cars and trucks engines are the same they wonât take time to re took a line just cause a car is going to a different country.