1998 LS400 Oil Turns Dark Quickly

[Gebo]

I bought this car in 2001 with 30,000 miles on it. Previous owner used Amsoil. I've used Amsoil for practically all of the additional 145,000 miles. Something I have noticed is that the engine oil gets dark pretty quickly. Say in 2000 miles, it is dark. I've had a few oil analysis done and they were fine. I use the Japan made Toyota filter. You know, the one with the sponge type material. I have used a Pure One a time or two to see if that made any difference. It didn't.

My other cars don't do this. Why does the LS oil get so dark so quickly? What should I check? PCV valve has been replaced? No check engine light ever.

 

[Quest]

colour means nothing to the oil, just goes to show that the oil (chemistry/additives within) is doing their job.

lighten-up! get a beer and enjoy your vehicle!

Q.

 

[DrDusty86]

My Zx2 does the same thing and has for the 8 years I've owned it. I use RP every 4500-6k and it is always BLACK by 2,000 miles. Changed PCV valve 3 times and tried other filter brands.. Just the way my car is I guess.

 

[DrDusty86]

My Zx2 does the same thing and has for the 8 years I've owned it. I use RP every 4500-6k and it is always BLACK by 2,000 miles. Changed PCV valve 3 times and tried other filter brands.. Just the way my car is I guess.

 

[synthetic_crazy]

Oil color is not a good indicator of oil life. For example, I changed the oil in my Corolla with Mobil 1 0w-30 and then checked the oil level the following day to verify that I had not overfilled it. Unfortunately, the oil level was higher than I had anticipated and I was forced to crawl under the car and drain out some oil. The oil going in the engine the preceding day was a nice golden brown color and the oil I drained out was a deep amber color. So, even after only a few miles the oil had changed color dramatically. Since then, I don't let oil color dictate when I change the oil in the car.

Don't worry about the color of the oil in your LS 400. Those engines, from what I have read, are very easy on oil. Enjoy that ultra nice car ... the LS series Lexus vehicles are my favorite cars on the road.

 

[Rand]

I noticed the same thing about the 4.0Sohc in my 2002 ranger and 2005 ranger I work on..

1000-1500 miles and it was darker than my focus (duratech) with 5k+ miles

 

[Gebo]

Originally Posted By: Quest
colour means nothing to the oil, just goes to show that the oil (chemistry/additives within) is doing their job.

lighten-up! get a beer and enjoy your vehicle!

Q.


I guess I could get a lemonade. It still makes me wonder, "Why?"

 

[Norm Olt]

You could probably install a by-pa$$ oil filtration $y$tem and capture the particulate that is turning your oil dark sooner than you expect, but...

Why?

If you've gone through the analysis routine and there is no real problem, just enjoy your lemonade!

Cheers!

 

[NextUpVeloster]

It is more to do with the oil than the vehicle. I change at 5000 miles and it is very dark by about 2000 or so as well. I even add when and if it burns some. Still, the oil is fine.

 

[Oregoonian]

The question is.....WHY.

Does anyone have a reasonable answer?

 

[NextUpVeloster]

Originally Posted By: Oregoonian
The question is.....WHY.

Does anyone have a reasonable answer?



Oil chemistry.

I cannot think of a more reasonable answer.

 

[HK_Ace]

My Subaru does it sooner- probably by 2,000 miles. It also revs ar almost 2,900 RPM at 70 MPH. My V8 4Runner revs at about 2,100 RPM at 70 MPH and does not turn oil dark till 5,000 miles. Maybe higher-revving and higher-compression engines do it quicker. I'm sure there are several reasons. I do like the fact that the $Runner is so easy on oil- must be a low compression and lazy V8 that affects oil less.

 

[Quest]

If the engine runs fine and been on religious maintenance/servicing regimen, oil changes dark rather quickly bears no meaning other than the fact that it's doing it's job keeping the engine innards clean.

Remember this: (a )your engine is not "young" nor "fresh off the assembly plant", meaning that as mileage reaps up, so is the aging of your engine.

(b ) oil is doing it's job by cleaning/suspending dirt and acids, etc. if your UOA reports no abnormalies, your oil is definitely doing it's job by keeping it clean (keeping the dirt, etc. in suspension).

Oil will never becomes clean/clear as corn cooking oil as it reaps up mileage in an engine in-service.

Lastly: if you think your gasoline engine is in a bad state of health, think diesel engines: in just a mere few hundred miles time: it will turn sooty black from corn cooking oil colour. Would diesel engine owners/operators freak out because of that?! I bet not.

Bottomline: you are being a worry wart. Just sit back and relax (and enjoy your ride).

Q.

 

[ARCOgraphite]

Originally Posted By: Oregoonian
The question is.....WHY.

Does anyone have a reasonable answer?

I think GEBO has to tell us WHICH amsoil he's using. If its NOT the synthetic Longlife stuff AND the oil has high detergency it will be scavenging ringpacks and heads on overtime. I've noticed this darkening when trying group III high detergency "phoney" synthetics (Castrol Syntec) but not in the past with the real PAO AMSOIL trisyn M1 with high TBN/DP. Now LOW detergency group II will usually look cleaner on the stick but leave the varnish in the engine. Most GF-5/SN are high DP now due to turbo deposit TEOST requirements and other increased cleanliness with the new std. I'll prefer a slightly varnished engine with oil of better lubricity that a sparkling motor that runs like a box full of rocks.

 

[Gebo]

Originally Posted By: ARCOgraphite
Originally Posted By: Oregoonian
The question is.....WHY.

Does anyone have a reasonable answer?

I think GEBO has to tell us WHICH amsoil he's using. If its NOT the synthetic Longlife stuff AND the oil has high detergency it will be scavenging ringpacks and heads on overtime. I've noticed this darkening when trying group III high detergency "phoney" synthetics (Castrol Syntec) but not in the past with the real PAO AMSOIL trisyn M1 with high TBN/DP. Now LOW detergency group II will usually look cleaner on the stick but leave the varnish in the engine. Most GF-5/SN are high DP now due to turbo deposit TEOST requirements and other increased cleanliness with the new std. I'll prefer a slightly varnished engine with oil of better lubricity that a sparkling motor that runs like a box full of rocks.


From 30K to about 140K I used the top of the line (most expensive) Amsoil. I then dropped down to the OE grade from 140k to 160K and currently using Kendall Full Synthetic. I did 10k OCI's from 30-140K and now do 5K OCI's.

 

[Gebo]

And you can see I change a lot of oil. I use the same for the 3 lexi and the Chevy van. The GS and the IS have the same engine and it stays light for almost the entire time. I wonder if any other LS400 owners can chime in with their observations.

 

[Oregoonian]

In the 50 thousand mile I've owned the 03' Ford Focus, I've used the following oils'...all 5w20...all synthetic.... and all with an OCI averaging 7500 miles.

M1-EP
Valvoline Synpower
M1
PP

The M-1 EP was the first oil I used after purchasing the vehicle with 57K on the OD. It turned dark very quickly, doing a beautiful job in cleaning up the engine.

After using the above (M-1EP), all the above oils used stood fairly clear, turning to a dark amber when changed.

Based on the above, I don't think that the answer to why oil goes black after 2000 miles is...oil chemistry. I must be something else.

 

[Hokiefyd]

Originally Posted By: Oregoonian
The question is.....WHY.

Does anyone have a reasonable answer?


I've asked similar questions before, and I believe it has to do with the engine itself, how the oil reacts to any existing deposits, etc. Oil chemistry may only be a partial answer, because the same oil used in two different engines will discolor differently, so there are clearly additional variables.

For example, nearly every single V-6 or V-8 engine I've owned will discolor the oil relatively quickly. And nearly every single 4-cylinder engine I've owned is very slow to discolor the oil, even the same oil used in both (such as M1 0W-20 most recently for example).

For one thing, a multiple-banked engine has two cylinder heads, so I suppose that, in theory, there are twice as many cylinder head deposits to control and clean. The I-4s have just one cylinder head. And my current V-6 engine takes the same (or even less) oil than my current I-4 engine. My old Northstars didn't discolor oil all that quickly, but they also had 7 quart sumps, instead of 4 or 5 quart sumps.

I also suppose that even if the piston rings are sealing exactly the same, you have 50% more blowby in a V-6 compared with an I-4, and 100% more blowby in a V-8.

In my experience, there is at least a strong correlation in the number of cylinders (or at least cylinder banks) and the rate at which an oil discolors, with a notable exception where the oil sump is sufficiently larger, so a given contaminant load is spread over a larger volume of oil.

 

[dave1251]

Originally Posted By: ARCOgraphite
Originally Posted By: Oregoonian
The question is.....WHY.

Does anyone have a reasonable answer?

I think GEBO has to tell us WHICH amsoil he's using. If its NOT the synthetic Longlife stuff AND the oil has high detergency it will be scavenging ringpacks and heads on overtime. I've noticed this darkening when trying group III high detergency "phoney" synthetics (Castrol Syntec) but not in the past with the real PAO AMSOIL trisyn M1 with high TBN/DP. Now LOW detergency group II will usually look cleaner on the stick but leave the varnish in the engine. Most GF-5/SN are high DP now due to turbo deposit TEOST requirements and other increased cleanliness with the new std. I'll prefer a slightly varnished engine with oil of better lubricity that a sparkling motor that runs like a box full of rocks.


You made zero sense. You stated that oil will clean while looking good on the dipstick yet will varnish the engine while cleaning the oil rings and heads. But does not provide sufficient protection, yet how many millions of vehicles are on the road right now with GF-5 oils, I do not see hoards of cars just spontaneous con-bursting on the highway. Your driving, maintenance habits or just plain old bad luck may destroy engines, but the overwhelming majority of the rest of us are not in the same boat. ARCO if the newest spec stuff is bad for your engines, just shop at K-Mart and clean out that GF-3 stuff, I even saw a Pennzoil PAO with Pennzane on the self. Ebay is a good place to buy the oil you are looking for also. But if you feel different please provide us with a scientific study on the matter why GF-5 levels of a particular anti-wear additive is destroying engines by the thousands, ZDDP is not the only one factor and not the only anti-wear additive because there is a symbiotic relationship between basestocks, detergent, and anti-wear additives. Because the overall make up of a motor oil is a whole lot more important factor than a individual part. The formulation of the motor oil for your car believe it or not is not inadequate for engine protection, because if it was inadequate there would be a lot of PCMO blenders out of business. Some may give you the sense of protection that you desire at a higher price point, and often you are paying for that sense of protection because it is a feeling nothing more.

 

[Gebo]

Originally Posted By: Hokiefyd
Originally Posted By: Oregoonian
The question is.....WHY.

Does anyone have a reasonable answer?


I've asked similar questions before, and I believe it has to do with the engine itself, how the oil reacts to any existing deposits, etc. Oil chemistry may only be a partial answer, because the same oil used in two different engines will discolor differently, so there are clearly additional variables.

For example, nearly every single V-6 or V-8 engine I've owned will discolor the oil relatively quickly. And nearly every single 4-cylinder engine I've owned is very slow to discolor the oil, even the same oil used in both (such as M1 0W-20 most recently for example).

For one thing, a multiple-banked engine has two cylinder heads, so I suppose that, in theory, there are twice as many cylinder head deposits to control and clean. The I-4s have just one cylinder head. And my current V-6 engine takes the same (or even less) oil than my current I-4 engine. My old Northstars didn't discolor oil all that quickly, but they also had 7 quart sumps, instead of 4 or 5 quart sumps.

I also suppose that even if the piston rings are sealing exactly the same, you have 50% more blowby in a V-6 compared with an I-4, and 100% more blowby in a V-8.

In my experience, there is at least a strong correlation in the number of cylinders (or at least cylinder banks) and the rate at which an oil discolors, with a notable exception where the oil sump is sufficiently larger, so a given contaminant load is spread over a larger volume of oil.

I also think it's funny that people will respond with a "chill out" response, or "don't worry about it". Having a curious mind and wanting to know a reason for something is very different from worrying about it and thinking there's a problem.


Thank you for the last 2 sentences. ;-)