Has Toyota solved the problems?
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Toyota still doesn't admit there was a sludge problem to fix. The PCV modifications mid 2002 were to help provide a greater margin of safety for owners who go over the recommended oil change interval.
Actually, there has been no design problems with toyota engines so no there was no "real" fix. The only problem with the toyota engines were the engineers who said "extend your drains" out to 5 and 7500 miles. Anyone who did 3k drain intervals with these engines experienced NO SLUDGE. So, what's the problem with this picture? No sludge in 3k drains but in 5 and 7500 miles you get sludge? Are we seeing the problem here? shorter drains=no sludge, longer drains=sludge? hmm, so, does the mechanical problem only appear after 3k but doesn't exist under 3k? The problem here is the type of oil that cannot be used to extend oil drains. You cannot use standard conventional bulk oil for anything over 3k drains. Period. There is NO Mechanical Failing component. They did not decrease the size of their block's water jacket, they didn't change the size of the pcv, but they DID CHANGE the OIl DRAIN INTERVALS which is WHAT CAUSED ALL THIS PROBLEM WITH THE SLUDGE.
Very simple. Evidence showed that after 3k of running on those engines with the heat and shearing of the conventional oil, that it would take a 30wt oil and break it down to a 20wt. A pcv valve will NOT Shear and oil down. A mechanical Force WILL, that's where the gear system they used would. Top off that will a tight engine compartment, no air flow across the engine, Oil sump capacity very limited, and now you have a sludge problem when trying to go beyond the 3k.
To eliminate the sludge issue on the toyota's, you must do one of a couple of things. 1- do not go past 3k if using a standard bulk otc conventional oil. OR... you can go with a good quality oil preferably with a higher ht/hs rating and extend out to 5k but should take at least one sample to verify that the oil hasn't dropped viscosity. Once that has been established, you can safely run that oil with no worries.
No other action is needed to avoid the sludge issue. Very simple.
Very simple. Evidence showed that after 3k of running on those engines with the heat and shearing of the conventional oil, that it would take a 30wt oil and break it down to a 20wt. A pcv valve will NOT Shear and oil down. A mechanical Force WILL, that's where the gear system they used would. Top off that will a tight engine compartment, no air flow across the engine, Oil sump capacity very limited, and now you have a sludge problem when trying to go beyond the 3k.
To eliminate the sludge issue on the toyota's, you must do one of a couple of things. 1- do not go past 3k if using a standard bulk otc conventional oil. OR... you can go with a good quality oil preferably with a higher ht/hs rating and extend out to 5k but should take at least one sample to verify that the oil hasn't dropped viscosity. Once that has been established, you can safely run that oil with no worries.
No other action is needed to avoid the sludge issue. Very simple.
Thank you for clearing this up Bob. So if I use a conventional motor oil then I should go the 3k mile oil change route but if I use synthetic then I can extend drains to 5k. Sounds like a good plan. Thanks.
Seems like to me, based on what Bob said, is that Toyota still has some work to do. A good conventional motor oil, like say Chevron, should be able to last 4000-5000 miles in any car or truck, including Toyota.
If those gear systems cause so much vixcosity shearing, they need to take a good look at that. Perhaps only motor oils that can survive a lot of that (like Mobil 1, Redline, etc.) should be used in Toyotas.
It probably would not hurt, either, to use a maintenance dose of Auto-RX or clean the engine before an oil change with Neutra.
If those gear systems cause so much vixcosity shearing, they need to take a good look at that. Perhaps only motor oils that can survive a lot of that (like Mobil 1, Redline, etc.) should be used in Toyotas.
It probably would not hurt, either, to use a maintenance dose of Auto-RX or clean the engine before an oil change with Neutra.
In addition, if Toyota has so many problems with sludge in engines if a vehicle uses conventional motor oil and that oil is used longer than 3000 miles, then how about everybody else? I realize that with the gear system in current design Toyota may be different than everybody else. But other car manufacturers are allowing 7500 mile oil changes or even more with conventional motor oil. Most people use conventional motor oil.
So, should eveerybody go back to recommending 3000 mile oil changes? Or 3000 mile oil changes if you use conventional motor oil, and 5000-7500 with an approved synthetic?
So, should eveerybody go back to recommending 3000 mile oil changes? Or 3000 mile oil changes if you use conventional motor oil, and 5000-7500 with an approved synthetic?
Mystic,
Toyota doesn't have work to do as there is nothing wrong with their engines, just maintenance practices, but FYI, Toyota has new engines out that have eliminated the inside gear design and like other manufactures are now using the outside gear design.
While others maybe doing the extended drain intervals does not mean everyone can. Each company prides themselves on their newer and more powerful designed engines. So, point is, just because your neighbor can sneak around with a girl friend and get away with it, does it mean that you can/should too? Maybe jumping off a bridge means others should as well. Not a good logical way to consider oil change intervals as each and every car, driver, location,fuel, and many other aspects are different and no one can predict extended drains for everyone safely. The 3k drain is the only safe level of drain interval when covering all vehicles. Amsoil states you can do 20k drain intervals on all vehicles with no problems... Try that on a sludge prone toyota seina v6 and see how far you get. point, do your own thinking, not follow a crowd just because..
[ July 03, 2003, 11:47 AM: Message edited by: BOBISTHEOILGUY ]
Toyota doesn't have work to do as there is nothing wrong with their engines, just maintenance practices, but FYI, Toyota has new engines out that have eliminated the inside gear design and like other manufactures are now using the outside gear design.
While others maybe doing the extended drain intervals does not mean everyone can. Each company prides themselves on their newer and more powerful designed engines. So, point is, just because your neighbor can sneak around with a girl friend and get away with it, does it mean that you can/should too? Maybe jumping off a bridge means others should as well. Not a good logical way to consider oil change intervals as each and every car, driver, location,fuel, and many other aspects are different and no one can predict extended drains for everyone safely. The 3k drain is the only safe level of drain interval when covering all vehicles. Amsoil states you can do 20k drain intervals on all vehicles with no problems... Try that on a sludge prone toyota seina v6 and see how far you get. point, do your own thinking, not follow a crowd just because..
[ July 03, 2003, 11:47 AM: Message edited by: BOBISTHEOILGUY ]
This is why I both love and hate the internet. No question there may be a problem with some Toyota engines. But knowing how severe it is and under what circumstances is impossible to gauge...
[ July 03, 2003, 01:12 PM: Message edited by: jsharp ]
I totally understand why the confusion off internet. As for toyota maintaining the same recommendations, well, that imo is their problem and like many help centers, many do not know any better when answering questions to the GP.
Myself, I look for answers and while in a big discussion with a toyota spokes person on a big forum chat room, I found his answers to be well thought out so not to imply any possible finger pointing towards them. You have to remember, you NEVER ADMIT GUILT no matter if you are or not. This is the AMERICAN WAY for legal matters.
So given I was satisfied with the answers toyota was giving out, I did some personal investigation at the local toyota dealership and since become friends with several of the ase certified toyota master mechanics who work there. Fact is, they even gave me a time card cause I spent so much time there under the hoods with these guys learning about the issue on sludge. After many hours with them, several oil analysis on engines running the bulk castrol, seeing the results of how that these engines were in fact shearing down the 30wt to a 20 inside of 3-4k miles, it became very apparent where the problem was.
Keep in mind that back before 96/97, the oil industry made a change and lowered/changed their oil formulations from the back then API SH oil to the API SJ. This is when they first reduced the zddp levels which is an antiwear additive. It wasn't until after this that sludge issues started to become apparent for toyota's.
My recommendations come from my own observations as to what has and is happening and not based on toyota's recommendation which is still not in line for those particular engines. 3k drains for standard conventional oil. 5k on a good ht/hs oil ok but pushing on from there, highly recommend oil analysis to verify how the oil will handle your particular situation. Follow these guidelines and you will not have sludge in those engines.
Myself, I look for answers and while in a big discussion with a toyota spokes person on a big forum chat room, I found his answers to be well thought out so not to imply any possible finger pointing towards them. You have to remember, you NEVER ADMIT GUILT no matter if you are or not. This is the AMERICAN WAY for legal matters.
So given I was satisfied with the answers toyota was giving out, I did some personal investigation at the local toyota dealership and since become friends with several of the ase certified toyota master mechanics who work there. Fact is, they even gave me a time card cause I spent so much time there under the hoods with these guys learning about the issue on sludge. After many hours with them, several oil analysis on engines running the bulk castrol, seeing the results of how that these engines were in fact shearing down the 30wt to a 20 inside of 3-4k miles, it became very apparent where the problem was.
Keep in mind that back before 96/97, the oil industry made a change and lowered/changed their oil formulations from the back then API SH oil to the API SJ. This is when they first reduced the zddp levels which is an antiwear additive. It wasn't until after this that sludge issues started to become apparent for toyota's.
My recommendations come from my own observations as to what has and is happening and not based on toyota's recommendation which is still not in line for those particular engines. 3k drains for standard conventional oil. 5k on a good ht/hs oil ok but pushing on from there, highly recommend oil analysis to verify how the oil will handle your particular situation. Follow these guidelines and you will not have sludge in those engines.
You're lucky Bob that your local Toyota dealer has good mechanics and you've been able to hang there and get some real first hand information and talk to knowlegable people.
My local dealer had my 4-Runner about 6 times to fix simple items on warranty and never did get it right. I finally gave up on them. I wouldn't dream of asking them about the sludge issues. They wouldn't know what it was if their coffee cups were filled with it...
My local dealer had my 4-Runner about 6 times to fix simple items on warranty and never did get it right. I finally gave up on them. I wouldn't dream of asking them about the sludge issues. They wouldn't know what it was if their coffee cups were filled with it...
My brother has a 2000 Toyota Siena van with an engine that is supposedly prone to sludge. When he bought it, the dealership emphasized that 7,500 mile oil change is all that is needed for most people's driving habits. He heard about the sludge problem shortly after he bought it and used 6,000 mile intervals instead of the recommended 7,500. He uses Exxon Superflo 5W30 and watches very closely for any sign of sludge. Now at 65,000 miles with no sludge.
What Bob said is absolutely right. What happend is Toyota's engines were just not capable of being that "nice" to oils by design and they gave the wrong intervals out. What amazes me is that Toyota is a "perfectionist" company when it comes to quality control. So either they didn't test it good enough or the conditions were not real world.
We have seen some synthetics pretty beat up at 7,500 miles and to think dino oil can make it that far is a stretch. It comes down to the fact that all engines handle oil differently. Some are easier then others on the oil and you can go further. The new Honda Accords can go 10k miles under normal conditions on regular oil now. I personally wouldn't ever go that far on a regular oil, but it might be possible if the engine is not as harsh on the oil. Bottom line as I see it is that you have to really have the oil analyzed to know what your capable of getting out of an oil. I've come to understand why Mobil 1 and others don't set a specific number out as too how long you can go before draining the oil. Part of it might be profit, but there is also a liability factor too.
[ July 03, 2003, 09:35 PM: Message edited by: buster ]
We have seen some synthetics pretty beat up at 7,500 miles and to think dino oil can make it that far is a stretch. It comes down to the fact that all engines handle oil differently. Some are easier then others on the oil and you can go further. The new Honda Accords can go 10k miles under normal conditions on regular oil now. I personally wouldn't ever go that far on a regular oil, but it might be possible if the engine is not as harsh on the oil. Bottom line as I see it is that you have to really have the oil analyzed to know what your capable of getting out of an oil. I've come to understand why Mobil 1 and others don't set a specific number out as too how long you can go before draining the oil. Part of it might be profit, but there is also a liability factor too.
[ July 03, 2003, 09:35 PM: Message edited by: buster ]
BTW, here's a pic of one new engine design I saw on the floor. This isn't a replacement engine for the sludge prone ones, but just to show how they are moving the cam gears outside of the oil galley area.
Yep. When people started using full synthetic oil instead of dino oil, the problem magically went away.
Bobs, Thanks for the very informative posts! I think that explanation clears it up for most of us.
Like I have been saying all along Toyota should revise their service schedules to reflect the real world. My 2003 still has the rediculous oil change intervals in the Manual of 5000 or 7500 which I will not participate in.
Daily Drives
-2003 Toyota Tacoma PreRunner XtraCab, Impulse Red, Peppy 2.7 Liter 4 Banger, Running Mobil1 Synthetics SS 5W-30.
ODO 4000 Miles.
-1995 Toyota 4-Runner, Evergreen, 3.0 V6, Running Mobil1 Synthetic SS 10W-30.
ODO 78000 Miles.
Like I have been saying all along Toyota should revise their service schedules to reflect the real world. My 2003 still has the rediculous oil change intervals in the Manual of 5000 or 7500 which I will not participate in.
Daily Drives
-2003 Toyota Tacoma PreRunner XtraCab, Impulse Red, Peppy 2.7 Liter 4 Banger, Running Mobil1 Synthetics SS 5W-30.
ODO 4000 Miles.
-1995 Toyota 4-Runner, Evergreen, 3.0 V6, Running Mobil1 Synthetic SS 10W-30.
ODO 78000 Miles.
I own a 99 Avalon and received the "oil geling" coverage letter a year ago. In that letter they said to stick to the existing maintenance. That is 5k severe service, which by their definition only includeds non paved roads, towing, and short trips in sub-freezing weather. Normal service , which most people fall under by THEIR definition is 7.5k. So Toyota is telling their customers that most of them need only change dino oil every 7.5K on these 97-2002 3.0L V6s.
I can remember back in '93 when I owned a Toyota Tercel. The dealership was in the process of changing from recommending Pennzoil oil to Valvoline (that dealership-I don't know about Toyota dealerships in general). My little Tercel only held 3 qts of oil. I don't think that Toyota had sludge problems back in those days, but I was so nervous with only 3 qts of oil that I started to use Mobil 1.
This makes me question how serious the problem really is. I have to believe that Toyota would make some drastic changes to service intervals if they had enough problems to be replacing a large number of engines.
I've also seen some comments on this forum and others that claim that one or two people constitute about 95% of the "Toyota sludge" information on the internet. It's starting to remind me of the Audis that were allegedly "possesed and could drive off on on their own" from a few years back. IOW, more myth than fact...
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