Synthetic oil ok?

[fabio420]

I was using regular 20w-50 oil in the car. We are rebuilding the head and changing the gaskets, and I was wondering If it's OK to use synthetic oil. I heard that due to the smaller particles, it leaks if regular oil had been used. If the bottom was being rebuild too, I figure this wouldn't be an issue. But is it an isssue? Can we use synthetic oil? I mean, I'm obviously draining my oil and coolant, and refilling it. So can I use synthetic?

[TheOne]

you should be able to, get something like mobil 1 synthetic 10w-40 or if there's 20w-50.(synthetic is not thinner than normal, the leaks depend on the weight of the oil, if oil that weights less is used then it'll leak, if the oil weights more then it most likely wont, this is from regular to the new oil weight)

[PalmerWMD]

I was using regular 20w-50 oil in the car. We are rebuilding the head and changing the gaskets, and I was wondering If it's OK to use synthetic oil. I heard that due to the smaller particles, it leaks if regular oil had been used. If the bottom was being rebuild too, I figure this wouldn't be an issue. But is it an isssue? Can we use synthetic oil? I mean, I'm obviously draining my oil and coolant, and refilling it. So can I use synthetic?

Particles in syn oil arent smaller, leaks really are a thing from 70's formulations of syn oils which had no seal thickeners.

You can use syn on a KAT as a winter oil Mobil1 0w-40 as asummer oil Mobil1 15w-50. <or> if on a budget 10w-40 Valvoline Durablend (winter) 20w-50 durabvlend summer.

Redline amsoil also make great oils.

Syntec is being improved one grade at a time currrently their Syntec 0w-30 ( MUST say meets ACEA A3 <not> ACEA A1 to get the right formula there are 2 0w-30 Syntecs out at same time) is also a very strong winter oil almost a ow-40 in weight and VERY stable.

Fred..

PS: Many syn users use a Mobil1 xw-30 weight the M1 30 weights are thinner than most 30 weights so I stay away= leaks possible but all otehr weights are good, especialy the 15w-50 for a KAT in summer

[MarkEmark]

I was using regular 20w-50 oil in the car. We are rebuilding the head and changing the gaskets, and I was wondering If it's OK to use synthetic oil. I heard that due to the smaller particles, it leaks if regular oil had been used. If the bottom was being rebuild too, I figure this wouldn't be an issue. But is it an isssue? Can we use synthetic oil? I mean, I'm obviously draining my oil and coolant, and refilling it. So can I use synthetic?

Before my engine was rebuilt I switched over to synthetic Mobil 1 (5W 30), and it immediately started leaking from the front main seal. After replacing this seal THREE, yes, THREE times, I switched back to Pennzoil and it never leaked.

So yeah, if you have a high mileage KA (mine had about 93 k on it), it could very well leak.

[WDRacing]

5W30 is to thin for my taste. I prefer the 20w50 blend. I use Syntec at the moment, but Mobile 1 will work just as well.

Thicker oil also helps prevent the oil from "coking" the turbo bearings.

WD

[All_Motor_KA]

I'll tell you guys this much, my friend has a 89 Camaro TBI 305 with almost 200k on the dial. He switched to synthetic about 30k ago. Since then he's changed heads, intake and has been spraying with no oil leaks. He changed his oil religouslly though. Something to think about, no?

[EstoMax]

im running mobil1 10w30 synthetic in mine.. its got that in it since previous owner supposedly, so engine should b used to it. i ran 5w30 in the winter months. i do lose some oil somewhere, i have no idea where though.

maybe ill try the 15w50 next time i change (i change every 3 months no matter what haha) including k&n oil filter

[PalmerWMD]

Before my engine was rebuilt I switched over to synthetic Mobil 1 (5W 30), and it immediately started leaking from the front main seal. After replacing this seal THREE, yes, THREE times, I switched back to Pennzoil and it never leaked.

So yeah, if you have a high mileage KA (mine had about 93 k on it), it could very well leak.

You were switching to one of the thinnest 30 weights on the market (thinner at operating temps than nearly all other 5w-30's, 10w-30's and 0w-30's)The viscosity played a role here rathjer than the nature of the molecules

[Checkered-Member]

I prefer the 20w50 blend.

who makes 20W-50?

[PalmerWMD]

who makes 20W-50?

Nearly every major oil , except for some drive-cleans, is available in a 20w-50 (or 15w-50 very nearly same thing)

RedlineAMSOILMOBIL 1 Mobil1 Ext Perf

Valvoline DurablendPennzoilChevron SupremeQuaker StateHalvoline.

a 20w-50 is one way to get strong filmstrenght if for some reason a syn is out of budget

OR you can get this grade in syn for even better filmstrenght think Turbo

[MarkEmark]

You were switching to one of the thinnest 30 weights on the market (thinner at operating temps than nearly all other 5w-30's, 10w-30's and 0w-30's)The viscosity played a role here rathjer than the nature of the molecules

It's impossible to know for sure if it was merely the viscosity or the nature of synthetic oil.

5W 30 is the NISSAN recommended oil for all temperatures, so 5W 30 is all I ever run. Perhaps I could have tried using a thicker mobil 1 but I wanted to use the NISSAN recommended viscosity.

I'm just giving my PERSONAL (not hearsay) experience.

[Jookmasta]

i have been running 15W50 for near a decade i think. mobil 1 always and im down south where the heat is consistent. No leaks at all and i second what fred said.

[fabio420]

Did your engine use regular oil before the synthetic? How many miles on the engine? The head is being rebuil, but for money reasons, the block is going to be left stock for now. It has 130K on it. Can I still use synthetic?

[PalmerWMD]

1)It's impossible to know for sure if it was merely the viscosity or the nature of synthetic oil.

2)5W 30 is the NISSAN recommended oil for all temperatures, so 5W 30 is all I ever run. Perhaps I could have tried using a thicker mobil 1 but I wanted to use the NISSAN recommended viscosity.

3)I'm just giving my PERSONAL (not hearsay) experience.

1)No its not impossible, as Mobil1 5w-30 is nearly a 20 weight oil, during running temps and these "leaking" complaints, come mostly from Mobil1 30 weight users

2) They are assuming a dino oil and in a Dino oil year around ( they dont trust american consumers to change oil weights with seasons anymore, like they used to) and you need a 5w- to assure decent start-up when its cold.

In order to accomplish a 5w-30 vs a 10w-30 you will have a less stable oil as the bigger viscosity range is accomplished via adding polymeric thickeners.These themselves decompose and turn into varnish in your engine, as well as thinning out your oil ,as you are losing them to thermal decomposition.

This is the single greatest contributor to varnish in modern engines..

So you want as few VII's like this as possible.

Why its <always> a better choice ,to go with 10w-30 vs a 5w-30, unless your in middle of a northern winter. (and if you have an application that needs high 8-mid 11's Cst viscosity at 212F oil temp)

Nissan oil recommendation is for a NEW + Unmodified nissan engines, nearly all engines here have lots of miles = different viscosity requirements

<Also> keep in mind you are posting in the KAT forum, unless stated otherwise ,an oil recommednation will always have to be for a aftermarket turbocharged engine.that means the owners manual flys out the window, since you now need to account for lubrication need of a turbo <and> changed lubrication needs of the engine itself ( due to higher temps)\

3)Mark the attitude I detect, is uncalled for.I will always give you the right information, what you do with it, is up to you.

Fred..

[fabio420]

So Fred, now that you know what my story is, and that I live in south FLA( always hot), which oil would you recommend? I don't mind it being pricey since I figure this is something I shouldn't skimp on. I sure apperciate it.

[PalmerWMD]

If limiting yourself to off-the-shelf oils ( as I do), it comes down to 3 oils:

Mobil1 15w-50Redline in 10w-40 (if very low mile + very tight engine) or 20w-50/15w-50.

Keep in mind this is assuming you are like most folks, in that you are not using a seperate oil cooler.

[paemt6220]

Fred is a Chemist!! I would imagine he might understand these things more than the average person. I think I would trust him before some others!

Chad

PS Fred, I could use a good, technical lesson on oil weights and the such!

[fabio420]

Thank you much! btw, what is oil coolant, and should I use it? How available is it?

[turbo90]

Oil coolant, hehe, good one; you are joking right? He means an external cooler, think small radiator but for your hot oil.

[Jookmasta]

i switched to synthetic as soon as it came out back in the 90s. i now have 150K and the motor couldnt be more happy. i say 15w50 for the sfl heat. what turbo 90 said is accurate. fred once again teaches me something new about oil. fabio i would source the mobil one synthetic from walmart for 24 bux or from cosco or bj's or sam's for like 22 for the case of six. redline will be hard to find at a decent price as mobil one and royal purple seem to be at the same price range these days.....................

[paemt6220]

!!

Thank you much! btw, what is oil coolant, and should I use it? How available is it?

Oil COOLER. Like turbo90 said, It is a small radiator for your oil. Cool oil is happy oil. Another benifet to a oil cooler is it adds more oil volume. That itself helps cool the oil and the KA doesn't hold very much oil, so more volume is a great safe measure.

Chad