Helpful to run a short OCI to clean, before...

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an extended OCI on full synthetic?

The Sienna in my sig now has 142K. I will put it on 10K OCIs with synthetic (filter and oil are already in my garage), but I want to key it to the odometer (in other words, I start a 10K OCI at 150K, then change it at 160K, etc.). I would just put in synthetic now, for an 8K OCI, except for one thing—I’m thinking that the engine might have lots of gunk in it, because it was not well maintained the first 120K miles. I looked on my spreadsheet and the average for that time was a conventional oil change every 8000 miles. Since then, I have changed it every 4000-5000 miles, with conventional (and one run with a synthetic blend). Throughout the minivan’s life, most of this driving has been city, short trips (5-10 miles per trip), with occasional romps on the freeway. The OEM recommendation was 5K conventional, but they have since added 10K with synthetic as being OK.

So what would be best for this engine---to just go on extended OCIs with full synthetic now, for 8000 and then 10,000 mile OCIs? Or would it be best to run something like MaxLife for a couple of short OCIs until it hits 150K? I’m wondering if all the buildup of grime during that first 120K miles would cause me any problems if I went to an extended OCI with an oil designed for one, with lots of cleaning agents to dislodge it (and last for a good 10K OCI).

FWIW, I brought it over to my trusted mechanic, and he said since there is no smoke coming out the tailpipe when I start it, and he looked at the dipstick and saw there was no grime or grit at all, that there was no reason to think I had a sludge problem.
 
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IMO, I think you should just continue to use conventional oil for 5k oci (IF YOU THINK YOU HAVE SLUDGE). I think you'd be fine with just going to straight synthetic, but if you feel like you need to do this, then don't do short ocis. Keep it at the 5k range - you won't be wasting your money on short oil changes, conventional will still have life in it at 5k oci and will still be cleaning.

I think you should do that until you personally think it is clean enough and then switch to your synthetic oil, you'd be doing that anyway with short OCIs anyway just fewer oil changes. I just don't think you should waste the money on short OCIs as it seems from the information you gave that if there is sludge or grime, it's not a lot (I don't believe you have anything to be worried about especially with no evidence of such sludge).

Again, JMO.

Edit:
Agree with WobblyElvis
 
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Can you easily pull the valve cover and do a check? A new valve cover gasket should be cheaper than an oil change to know what your next course of action is.
 
I've never done that before. I'm wondering how much a first time valve cover operation would take...


Originally Posted By: Reddy45
Can you easily pull the valve cover and do a check? A new valve cover gasket should be cheaper than an oil change to know what your next course of action is.
 
I know someone who was in a similar situation, with a 2005-2007 Toyota Avalon. Do not remember the exact year. He was 6000 miles away from a round mileage number. As a clean up he ran two 3000 mile intervals with SuperTech 5w30 High Mileage and one Fram Ultra filter for both oil changes. Then at the round number he switched to Redline 0w20 and successfully runs 10k mile oil changes now. The first SuperTech oil change made the oil very dark quick. On the second 3000 mile oil change - the oil was just dark brown color, but much lighter than the first one. Try doing two short 4k mile oil changes with something cheap and "high mileage" formula, since those formulas usually contain extra detergents and conditioners as compared to the regular oil. And then switch to 10k OCIs and enjoy life.
 
An easier way to check for sludge is short (3-4K) runs of PYB & a decent, inexpensive filter (a Tough Guard would be a good choice), then cut the filters & see what they catch. 8K would be perfect to do it twice.
 
Just to clarify, I'm not worried about sludge per se, so much as loads of varnish and grime that might have collected on the engine, to be all pushed into my oil for 10K when I use a full synthetic for an extended OCI.
 
If there is "varnish and grime" formed from the first 120k miles, it's not going to come off with a couple of short ocis.

I would either forget about it, or pick a high detergency low Noack oil and run that for 7500 miles or less from here on out.
 
Originally Posted By: paulri
Just to clarify, I'm not worried about sludge per se, so much as loads of varnish and grime that might have collected on the engine, to be all pushed into my oil for 10K when I use a full synthetic for an extended OCI.


You'll need to remove the front valve cover to properly check for varnish etc. My 98 Sienna had lots of varnish and some small bits of sludge in the corners. I used Mobil 1 and Castrol edge black bottle for many of the oil changes. Never saw a noticeable improvement in the varnish.

I believe those Toyota V6 can develop sludge and varnish. Your 3.3 not as much as my 3.0. Due to that fact, I don't think I would run any OCI to 10k on those motors unless it was spotless inside. I would be more comfortable with a 7500 mi OCI.

It's not hard to remove the front valve cover. I removed mine at least 5 times and never changed the gasket. Before I sold the van one of the valve cover bolts broke, but what did I care, I was getting rid of it.
 
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That 2005 does not have the 1mzfe sludge engine. Even in that engine the problem was corrected in about 2001. You should be fine.
 
Correct. I am really more concerned about those 8K mile conventional OCIs I put on it, not really thinking that this is one of those sludge monsters.
 
We just bought the Highlander in my sig. It had 122K on it. I have the records where the oil had been changed every 5K (it varied from 3k to 6k). We are using the cheapest Amsoil for 3k with a Napa Gold Filter. At 125K we will drain and go with a "best" grade of Amsoil. We are still discussing which one. I am figuring one quick change with the Amsoil will get most of the other oil out and have the engine primed for the really good stuff. (I still have about 20 of the old Toyota Japanese made oil filters)

If I were you, I'd do a 3k change at 145k and another another at 150K with your "cleanup" oil and good filters. Then at 150K I'd put the full synthetic and a great filter on. I can promise you, you will sleep better. Is is a waste of money? Probably, but if you are like me it will be worth it.
 
Originally Posted By: BenzFella
I know someone who was in a similar situation, with a 2005-2007 Toyota Avalon. Do not remember the exact year. He was 6000 miles away from a round mileage number. As a clean up he ran two 3000 mile intervals with SuperTech 5w30 High Mileage and one Fram Ultra filter for both oil changes. Then at the round number he switched to Redline 0w20 and successfully runs 10k mile oil changes now. The first SuperTech oil change made the oil very dark quick. On the second 3000 mile oil change - the oil was just dark brown color, but much lighter than the first one. Try doing two short 4k mile oil changes with something cheap and "high mileage" formula, since those formulas usually contain extra detergents and conditioners as compared to the regular oil. And then switch to 10k OCIs and enjoy life.


This sounds like one of the best options to me.
 
Originally Posted By: BenzFella
I know someone who was in a similar situation, with a 2005-2007 Toyota Avalon. Do not remember the exact year. He was 6000 miles away from a round mileage number. As a clean up he ran two 3000 mile intervals with SuperTech 5w30 High Mileage and one Fram Ultra filter for both oil changes. Then at the round number he switched to Redline 0w20 and successfully runs 10k mile oil changes now. The first SuperTech oil change made the oil very dark quick. On the second 3000 mile oil change - the oil was just dark brown color, but much lighter than the first one. Try doing two short 4k mile oil changes with something cheap and "high mileage" formula, since those formulas usually contain extra detergents and conditioners as compared to the regular oil. And then switch to 10k OCIs and enjoy life.


Yes, not a bad plan. I would even add some MMO from Walmart for a little extra slow yet effective cleaning.
 
I’m re-examining my situation, and I’m now questioning the necessity for doing any more short OCIs, even with an oil like MaxLife, with aggressive cleaning agents. I just looked at my maintenance records, and saw that I actually already have been recently running my car through a few short OCIs. When I change my oil this weekend, I will have had 5 oil changes in the past 23,000 miles (an average of 4,600 miles per OCI), which should have been more than enough to have dissolved any semisolid gunk in the engine. The first 120,000 miles were with an average of 8000 mile OCIs (and conventional), but since then, I’ve been more regular about it.

Varnish or grime that has been hard baked onto the engine will probably be much slower in coming off, than a short OCI would get off, so even if there is some cleaning going on, I doubt it will be so much that my filter will be overwhelmed. I think I’m good to go now, for an 8K synthetic run. When I hit 150K, I’ll then do 10K OCIs.
 
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