So I think I'll stay away from Quaker State synthetic oils...

When I did my last oil change, I decided to switch to synthetic before the dyno tune on the Subaru. So I went with Quaker State full synthetic 5w-30 oil. After about 500 miles on the oil, I noticed my oil pressure dropping. I lost about 30psi hot cruise (90psi to 60psi) and 20 psi hot idle (30psi to 10-12psi). I was like, wtf???? So at 1200 miles I drained it, and it came pissing out like water!!!! Really? After only 1200 miles? It was still fairly clean, just wicked thin... So I changed the filter and filled it up with Rotella 15w-40 and my oil pressure came right back. Will report on it later...

bizarre...

I suppose it would be horrible for me to speculate that it might not be the oil...

It's a possibility. That's why I said I'd report back...

I chose QS because it seemed to be reviewed favorably. But I also used their conventional oil for one of the "break-in" oils and it too, came out like that after only the initial heat-up. I only ran the car to temp on the first fire and then drained it immediately. Acted the same way. Weird.

+1 on it not being the oil either!
Jim

jayoldschool wrote:

I suppose it would be horrible for me to speculate that it might not be the oil...

Extreme Heat Cycle?

Bill are you running a turbo timer?
Jim

Sell it now......

No turbo timer. Those are not necessary.

You know, phuck you guys... I try to post a review of an oil that I had issues with (while other brands have been fine) to try and save you some aggravation and you give me sh!t about my car. Enough already.

Nice mouth Bill.

I have never been a quakerstate fan. Have run Pennzoil. Currently running Mobil 1 in Impala, but that rarely goes over 1000 between changes. The Wagon is on Amsoil running 10-12k miles between changes with a filter at 6k.

BigBlackBeaSSt wrote:

Nice mouth Bill.

I have never been a quakerstate fan. Have run Pennzoil. Currently running Mobil 1 in Impala, but that rarely goes over 1000 between changes. The Wagon is on Amsoil running 10-12k miles between changes with a filter at 6k.

+1 on not being a QS fan. I normally run Castrol, even though they are owned by BP

Just our opinions Bill but personally I already know QS oil sucks big time.Wish you well concerning
your Subie!
Jim

Bill:

Appreciate the heads up but the other guys may be right. Used to use QS 10W-40 conventional for all my gassers but the new stuff seems a little wonky. The only way any of the oils used today can loose its viscosity to that extent is either a chemical reaction or heat. As the oil came out clean, I would suspect heat.

More than likely, the additive pack in the synth is the same as used in the conventional oil. Viscosity improvers are usually very stable but can and do breakdown with age and HEAT!!!

Still learning about the Subby engine(s) but if your engine oil is getting hot enough to break down the VIs I suspect somethings amiss. Could be the turbo but its more likely the oil cooler if one is installed. Many of them have a thermostat installed to bypass when its really cold. Could be the thermostat is stuck closed.

You say it doesn't happen with your 15-40 Rotella. Is there any reason your using an oil specific to diesels? While they share the same base stocks, the additive package is completely different. I do know they do work in gassers (used to buy Rotella by the 5 gallon pail and occassionally used it my gassers when I was stuck) but how well it works is anyones guess.

Might be worth an oil analysis to see what took out the QS. For now I'm sticking with the Mobil One for the Caddy and the Rotella for the oil burners.

Bill

I run Castrol GTX in my wagon and have no issues. Have used it for years...not synthetic, just normal GTX. I change oil every 3K.

I've never really heard to much bad about Quaker State, but a lot of mechanics I worked with in the past said Pennzoil was garbage, so I've avoided it.

Never a dull moment.

-Mike

I have seen many tests that rate synthetic well above dino oil. I have run Pennzoil synthetic for years in the wagon and 2.2 ecotec Vue. It has had a steady diet of it after break-in. I used dino to break it in, oil change at 1,000 then 3,000 then went to synthetic. I have run Pennzoil 5w-30 Penn full syn 6,000 miles from that point on. It is close to 150k miles with NO issues with the car, no loss of fuel mileage, no wear noises, etc. It is a guttless engine with a stick so I rev the crap out of it when I drive it. My wife is hard on curbs and clutches. but she does not rev it like I do. I am confident that it has another 150k in it.

I put the wagon on Mobil one when I first got it. It had a noisey lifter and it helped to clean and quiet her down. I then went to Pennzoil sny at that point with 6k intervals. I switched 20k miles ago to Amsoil which has HUGE mileage claims (25k) but I run it 12k with a filter change at 6k. The lifters (1) have gradually got noisy over the next 100k. I put an oil pump and rod & main bearings in it about 30k miles ago and that helped some, but soon it will need a refresh. Maybe next fall I will build another motor and do a swap, but it still will not be a hot rod.

Sorry guys, i meant to have a smilie in there.

Yeah, i wish i had thought about oil analysis. But i didn't and drained it into a dirty contaminated pan. Boo. Or... Fail. Lol

I ran pennzoil before this QS and it looked normal after 500 miles. Curious to see how the Rotella performs.

There is some really informative stuff on this over at [You must be registered and logged in to see this link.]

Look under the articles tab for some eye opening info.

Bill

Two things to add to this discussion.
1- Check the factory specs for SBC engines. They do not require the
high oil pressures mentioned here!
In fact LT engines were designed for only 24psi oil pressure!

2- check out the site attached for the chart info on oil additives. This info is not only for flat-tappet cams, even tho that is what the article is about.
[You must be registered and logged in to see this link.]
The info on zinc additives is very critical.
P.S. - I lied!
3- GM years ago put out a bulletin that multi-grade oils, in some brands did not meet their performance specs!
Consequently, they withdrew approval of oils that spanned more than 2 grades,i.e. 10w-30 was O.K. but
10w-40 was not, in some brands. Therefore if you had any lube problems and they found 10w-40 in your
engine ----- tough luck, no warranty!
I have not heard of any repeal of that policy, even with the new synthetics.

rk, read the first sentence of the first post in this thread.

jayoldschool wrote:

rk, read the first sentence of the first post in this thread.

"When I did my last oil change, I decided to switch to synthetic before the dyno tune on the Subaru. So I went with Quaker State full synthetic 5w-30 oil.
So----????????? How does that apply?

Quote :

When I did my last oil change, I decided to switch to synthetic before the dyno tune on the Subaru

Does that help?

81X11 wrote:

I run Castrol GTX in my wagon and have no issues. Have used it for years...not synthetic, just normal GTX. I change oil every 3K.

+1...make that +2. Years ago I switched from Mobil 1 to Castrol GTX in my first Buick GN after a rod bearing spun at 110,000 miles. That motor went strong thru the 230,000 mile mark after a rebuild and the Castrol. With my current GN (113,000 miles) and the wagon I have switched from the Castrol GTX to the GTX High-Mileage for what it's worth. I tend to go 4000-5000 miles between changes too. Knock on wood, all is good!

I have used nothing but the Castrol GTX blended oil since it came out and have had zero
problems.Been using Castrol GTX since 1980 or thereabouts.
Jim

jayoldschool wrote:

Quote :

When I did my last oil change, I decided to switch to synthetic before the dyno tune on the Subaru

Does that help?

NOPE! Are you referring to the fact that he switched to synthetic oil, or the spread of the grade designation, 5w-30?

Nope, I was referring to your post that was based on LT1s. He is not talking about oil for LT1s. Oil for high revving turbo motors is completely different than low rev/low stress V8s.

Here's your post.

Quote :

Two things to add to this discussion.
1- Check the factory specs for SBC engines. They do not require the
high oil pressures mentioned here!
In fact LT engines were designed for only 24psi oil pressure!

2- check out the site attached for the chart info on oil additives. This info is not only for flat-tappet cams, even tho that is what the article is about.
[You must be registered and logged in to see this link.]
The info on zinc additives is very critical.
P.S. - I lied!
3- GM years ago put out a bulletin that multi-grade oils, in some brands did not meet their performance specs!
Consequently, they withdrew approval of oils that spanned more than 2 grades,i.e. 10w-30 was O.K. but
10w-40 was not, in some brands. Therefore if you had any lube problems and they found 10w-40 in your
engine ----- tough luck, no warranty!
I have not heard of any repeal of that policy, even with the new synthetics.

Make sense now?

jayoldschool wrote:

Nope, I was referring to your post that was based on LT1s. He is not talking about oil for LT1s. Oil for high revving turbo motors is completely different than low rev/low stress V8s.

Here's your post.

Quote :

Two things to add to this discussion.
1- Check the factory specs for SBC engines. They do not require the
high oil pressures mentioned here!
In fact LT engines were designed for only 24psi oil pressure!

2- check out the site attached for the chart info on oil additives. This info is not only for flat-tappet cams, even tho that is what the article is about.
[You must be registered and logged in to see this link.]
The info on zinc additives is very critical.
P.S. - I lied!
3- GM years ago put out a bulletin that multi-grade oils, in some brands did not meet their performance specs!
Consequently, they withdrew approval of oils that spanned more than 2 grades,i.e. 10w-30 was O.K. but
10w-40 was not, in some brands. Therefore if you had any lube problems and they found 10w-40 in your
engine ----- tough luck, no warranty!
I have not heard of any repeal of that policy, even with the new synthetics.

Make sense now?

No, because lubrication is lubrication, which I have studied in the past.
Too many fallacies about lubrication needs in internal combustion engines.
Read some studies on internal friction and lube properties-- you will be amazed!
I only referenced LT-1's because is is one form of a SBC, that is used in our longroofs.
Sorry if I confused you.

Thank you so much for enlightening me! I was so confused. I will get reading right away so someday I can (hopefully) understand lubrication in internal combustion engines as well as you.

jayoldschool wrote:

Thank you so much for enlightening me! I was so confused. I will get reading right away so someday I can (hopefully) understand lubrication in internal combustion engines as well as you.

Now, now --- let's stay friendly.
Not trying to nit-pick, but if you read some of the lubrication textbooks that are now
out-of-print that were published by Texaco years ago, you would be amazed at
the many factors they consider in the formulation of todays lubricants!
However, recently some compromises have been made in specific formulations
to be politically correct, and these have had detrimental side effects to some
engine enthusiasts.
There is a lot of good info out there, but things are changing so rapidly in this electronic era,
sometimes it is hard to keep up with all the technology --- or the reasons for the changes.

rk, you're beating a dead horse here. I have modern roller V8s. I also have a turbo 4 cyl. I also happen to have older V8s with flat tappets. One with a cat, two without. I am well read on oil, and how it has changed, as well as what different engines require.

Perhaps someone else will be inspired, though.

politics,. oil,. religion,.all guaranteed to encourage opposing opinions, all sides having merit

Bottom line is, make sure the motor has enough oil,. light oil is easier for oil control,and helps with start up wear and tear,.. heavy oil gives psychological comfort with the added pressure,dissapates heat better,..
pressure is just a measure of volume against resistance,
lets now discuss antifreeze,.another good bandwidth waster,.
thin oil isn't necessarily a bad thing.
I think $25.00? gets you an oil sample analysis, saves a lot of guessing,..

Nick

Nick,where were you a week ago when this oil thing got started!Concise and to the point.
Thanks
Jim