Fully Synthetic Oil?

kuziwk · June 2, 2010

im not really sure whats in the car, which is a 92 ls400 with 314, 000 km or 200 000 miles. The car recomends toyota brand, i was thinking of putting castrol fully synthetic, would this be bad, should i just use toyota? Also ive considered putting bitron additive. Also my recently replaced power steering pump is whining upon start, is there something i can add?

intakerGS · June 2, 2010

There's something you can 'add'...common sense. :cheers:

In short, these type of additives, mostly based on chlorinated paraffins, can harm your engine under high temps, despite what you see in adds. Therefore, responsible and leading engine oil manufacturers use safe and non-corrosive sulphur/phosphorus compounds.

For maximum protection, it's best to change oil every 3K miles or six months. Synthetics can last a bit longer, around 5K miles. Some reports state that changing to synthetics, after many years of regular oil use, may shrink the gaskets and cause oil leaks. True or not, I wouldn't bother using synthetic oil, if you keep up to the 3K or 6 months interval and some TLC.

Possibly there's some air in you PS pump. Use the 'search' feature on this site; lot's of topics re. PS pumps and how to solve their grunts...

Hanging In There · June 3, 2010

There's something you can 'add'...common sense.

In short, these type of additives, mostly based on chlorinated paraffins, can harm your engine under high temps, despite what you see in adds. Therefore, responsible and leading engine oil manufacturers use safe and non-corrosive sulphur/phosphorus compounds.

For maximum protection, it's best to change oil every 3K miles or six months. Synthetics can last a bit longer, around 5K miles. Some reports state that changing to synthetics, after many years of regular oil use, may shrink the gaskets and cause oil leaks. True or not, I wouldn't bother using synthetic oil, if you keep up to the 3K or 6 months interval and some TLC.

Possibly there's some air in you PS pump. Use the 'search' feature on this site; lot's of topics re. PS pumps and how to solve their grunts...

I second this suggestion, there's just nothing better than good quality dino oil, there's some lubricants that are much more expensive but they're no better when it comes to lubricating your engine. Just keep up the three month/3000 mile change intervals and stay away from additives.

SW03ES · June 3, 2010

Let me say first I would not switch to Synthetic oil in this car with that many miles on dino oil. I'd be worried about leaks...and its just not worth it.

However, I disagree with the statement that Synthetic oils do not lubricate better than dino oil. That may be true when the oil is fresh, but dino oils break down much more quickly than synthetic oils. When you look at oil analyses with Synthetic oil and dino oil even at 5,000 miles (the recommended severe change schedule on a Lexus) the synthetic oil is much healthier and better lubricating at that point. Synthetic oil also has less paraffins that stiffen up when cold, so cold viscosity is better for cold startups. Synthetic is just a better product.

However, if you change the oil every 5k...you probably see no benefit to synthetic oil. I have changed my oil every 5k with Mobil 1 synthetic since the first oil change...but I'm aware its probably not worthwhile. Now if I wanted to try and do 10k intervals...I'd see a big benefit...but I'm not willing to do that.

On the new Lexus and Toyota cars they use synthetic oil and the reccomended change interval is 10k miles FWIW...

kuziwk · June 3, 2010

Let me say first I would not switch to Synthetic oil in this car with that many miles on dino oil. I'd be worried about leaks...and its just not worth it.

However, I disagree with the statement that Synthetic oils do not lubricate better than dino oil. That may be true when the oil is fresh, but dino oils break down much more quickly than synthetic oils. When you look at oil analyses with Synthetic oil and dino oil even at 5,000 miles (the recommended severe change schedule on a Lexus) the synthetic oil is much healthier and better lubricating at that point. Synthetic oil also has less paraffins that stiffen up when cold, so cold viscosity is better for cold startups. Synthetic is just a better product.

However, if you change the oil every 5k...you probably see no benefit to synthetic oil. I have changed my oil every 5k with Mobil 1 synthetic since the first oil change...but I'm aware its probably not worthwhile. Now if I wanted to try and do 10k intervals...I'd see a big benefit...but I'm not willing to do that.

On the new Lexus and Toyota cars they use synthetic oil and the reccomended change interval is 10k miles FWIW...

so which oil do you guys suggest? does it have to be toyota?, because i hate going to the stealership.

killerFatty · June 3, 2010

Use whatever oil you choose. It doesn't matter. FYI toyota doesn't make oil. They just buy it wholesale and slap their logo on it. Castrol GTX is one of my personal favorites dino oils. I switched to mobile 1 on 175K miles and had no problems so just regulerly change your oil and you'll be fine.

As far as your PS pump, check the fluid level. If its low it will whine when you turn.

xxiiac · June 3, 2010

I bought my Lexus with about 100k miles. I started using synthetic oil when I got it. I then started to get leaks in several places. I did some searching on this site and found the leaks were possibly due to the synthetic oil. I switched back to reg oil (Castrol High Mileage along with the Castrol high mileage filter) and the majority of my leaks have disappeared. I don't think it is a coincidence.............

kuziwk · June 3, 2010

I bought my Lexus with about 100k miles. I started using synthetic oil when I got it. I then started to get leaks in several places. I did some searching on this site and found the leaks were possibly due to the synthetic oil. I switched back to reg oil (Castrol High Mileage along with the Castrol high mileage filter) and the majority of my leaks have disappeared. I don't think it is a coincidence.............

K cool ill pick up some castrol high mileage, I've got 200k miles on it so.....yea the ps pump only whines on cold start than goes away, just annoying because a lexus should not make noises, lol. Mechanic couldn't figure it out, should I change the oil to atf fluid? Not sure what was in before.

SW03ES · June 3, 2010

Yep, whatever brand oil you choose. Nothing special about the Toyota oil.

xxiiac · June 5, 2010

K cool ill pick up some castrol high mileage, I've got 200k miles on it so.....yea the ps pump only whines on cold start than goes away, just annoying because a lexus should not make noises, lol. Mechanic couldn't figure it out, should I change the oil to atf fluid? Not sure what was in before.

Maybe the ATF has never been changed in your car and that may be causing the whining. Try flushing the ATF, pretty easy job. I think that Lexus specifies Dextron II, which I got at NAPA for like $2.50 a qt. First remove the power steering pump resevoir cap, then the return hose that connects to the resevoir. Make sure the end of the hose goes into some type of bucket for the old ATF to go into. Then just start the car for 1-2 seconds and shut back off. When you turn the car on, it pumps old fluid out of the system into the bucket. Add some new ATF to the resevoir. Keep doing this process until you see new fluid coming out of the return hose, this will mean all the old fluid is out of the system. It will take a while and maybe 3-5 qts will come out into the bucket. I made it easier when I took off the return hose, I pulled it down through the engine compartment towards the floor, that way the fluid drains straight down into a bucket. I just did this and the old stuff that comes out is a brownish-red. The new stuff will be a bright red. If it still whines, then there is a power steering solenoid (or something like that) near the steering rack under the car on the drivers side that can be removed and cleaned. Good luck.