2006 Highlander 3.3L 3MZ-FE Heavy Sludge

[RayManPE]

2006 Highlander bought on OfferUp two years ago 120K miles .. no maint records… Everything looked great. Runs like a top. We've done Oil changes every 5K w 5W/30 syn blend. Last oil change 160K noticed oil leak though front valve cover. Took it off and found this cake/sludge. Cleaned the cover...air/oil chamber best we could. Didn't touch the sludge. Replaced the oil pressure sensor, pvc valve.
Ran transmission fluid/Seafoam. Put in new oil/filter ... oil light comes on at higher RPMs and goes off when reduced.
Dropped the oil pan & cleaned the intake screen .. still getting sludge/carbon in the filter. Oil light comes on at higher RPM's.

I want to take the valve cover off the front bank again & physically remove some sludge/cake and then run the BG Dynamic Cleaner/Rinse.
I'm not taking off the plenum to get to the back bank ... any other suggestions?

 

[Glenda W.]

Yikes! That’s a severe case. IMO you may have to disassemble and physically clean as much as you can. Cleaners will continue to break free chunks and cause problems. I’ve had Volvos where I had to physically clean the engine, not fun..

 

[slacktide_bitog]

Welcome to BITOG

Yeah, that's why I hate transverse V6 engines, and Toyota's are even worse because getting to the back is impossible

Get some toothbrushes

Do a bunch of fluhses, each time using 2 bottles or cans of the engine flush of your choice, each time running it longer than it says to run it, maybe a 10-mile trip on it at least, for example. Very short OCI's like every 1k, then doing the ultra flush cycle I just mentioned.

Once it finally looks clean again, use full synthetic oil every 3-5k.

And unfortunately, you will need to pull the rear valve cover, as the sludge in the back is often even worse than the front

 

[Chris142]

I think cleaning that much goop out may cause more problems. Maybe pull the pan again and pressure wash it from the top down!

I would be inclined to just leave it as it wont hurt anything if it stays put.

 

[BMWTurboDzl]

Drain the oil.
Fill the engine with diesel fuel and let it sit for a couple of days.

 

[gfh77665]

Thats your first post, welcome!!

We don't know your background / experience. You might be an ace mechanic for all I know. If not, I would consider taking it to a pro to remediate it. Thats what I would do. That back cover needs to come off, doing 50% of the job is not best. If you are a experienced DIY guy, then physical removal is the big first step. All sorts of cleaners / oils like Valvoline Restore & Protect are ready for you to use afterwards. Thanks for the pics, do follow up!

 

[Drewby83]

Holy moly that is a maintenance schedule of abuse. Let some sort of solvent soak the sludge for a few days, stretch your arms, get a wire brush kit, and some pain killers? Follow with short interval of a cleaning oil like a Valvoline restore and protect or the HPL offerings with some short intervals.

 

[Furious]

I am betting the OCV screens are clogged up pretty bad.

Me personally I would scrape as much off as possible, change the oil with the cheapest off the shelf like Supertech, run it for a very short period keeping an eye on oil pressure, change the oil and the filter and switch to Valvoline Restore & Protect.

Clean or replace the OCV screens.

 

[ripcord]

Maybe best to leave the valve cover on and just trade it in?

 

[userfriendly]

Used car dealerships will drain the oil, leave the filter and drain plug off, then pressure wash the engine.
Blow dry with compressed air, refill with oil and move on to the next car.

 

[wavinwayne]

Drain the oil.
Fill the engine with diesel fuel and let it sit for a couple of days.

Then set it on fire and walk away. Sludge gone. In all seriousness, I'm inclined to agree with @Chris142, to just leave it alone other than changing the oil on a regular basis.

 

[RayManPE]

Well, it’s my buddies car and he didn’t want to spend a lot of time and effort on it… He was just going to junk it but I’m talking him into trying BG dynamic cleaner/rinse… It looks like it’s gonna work… Of course if it’s not 100%, then we’re gonna end up clogging something up.

btw I am a retired engineer… DIYerselfer
work on my Toyotas and Honda. Hang out on sienna chat and Toyota nation Honda chat rooms

 

[AdmiralYoda]

I don't think that orange RTV came from Toyota....someone's been there before. My guess is that the oil light kept coming on because the screen was getting plugged. Mechanic probably told them to get rid of the car before it goes boooom..... now congrats on your purchase! In addition to poor maintenance the filter was probably plugged and the engine was in full bypass with zero filtration forever.

Supertech from Walmart is good cheap oil, buy a bunch and their cheap oil filters too. Lots of short OCI's..... I wouldn't use BG's Dynamic Cleaner/Rinse yet. Get the chunks out first.

1. Fill your engine up with a TON of diesel. Let it sit for a couple days. Drain and fill with oil.
2. Change the filter every 100 miles and change the oil at like 500 miles.
3. Get your favorite Motor Flush and and new oil and flush it out. Drain it.
4. Take the pan off and clean the screen. Fill it up with fresh oil and drive 1k miles, changing the filter at 500 miles.
5. Repeat steps 3-4 a couple times.
6. Get some of HPL's EC30 engine cleaner. It is a great oil and a great cleaner. Run it for 2k miles, changing the filter every 500 miles.
7. Clean the screen again and inspect under the valve cover.
8. Now run full synthetic and longer intervals, changing the filter often. Every time with a bottle of HPL EC30 in there.

Welcome to your new hobby!

 

[ripcord]

Then set it on fire and walk away. Sludge gone. In all seriousness, I'm inclined to agree with @Chris142, to just leave it alone other than changing the oil on a regular basis.

That would be my choice if I was going to keep the car. 3k oil changes using Costco or SuperTech synthetic and cheap oil filters.

My strong feeling is that flushes with strong solvents and such are just asking for a plugged up oil pickup and no amount of "product" is going to clean that engine up without manually scraping it out.

 

[OilStainedNapkin]

Does it burn any oil?

 

[RayManPE]

Car was running good until, oil light never came on ... perhaps it was on borrowed time.
Once we took the front valve cover off & messed around with it, trouble began.
Like I said, we ran transmission fluid, drained & refilled with an engine cleaner, etc.
We dropped the oil pan a couple of times to clean that filter ... the red RTV was done by us and now there's a cork gasket until we finalize the clean up, then we'll use the correct sealant.
Can't really drive it as the oil light keeps coming on. I think carbon remnants keep blocking the screen in the oil pan.
The BG "Sales rep" recommends clearing the chunks before using the cleaner/rinse.

I can drive at 25-30mph then when the light comes on, drop to neutral, shut off, restart and I'm good ... for a while.
I'm thinking, based on "sales rep" experience & other review, the BG cleaner will liquify the carbon & we'll be good.
Could do it twice ... $600!

 

[ripcord]

I'm confident that BG will not "liquify" that kind of carbon buildup.

Have you verified the low oil pressure with a mechanical gauge? The oil pressure sending unit might be faulty.

 

[oilfan99]

I wonder if they just did the free oil changes from toyota care then just neglected...

 

[RayManPE]

I'm confident that BG will not "liquify" that kind of carbon buildup.

Have you verified the low oil pressure with a mechanical gauge? The oil pressure sending unit might be faulty.

No, but we were think we should ... tried with my OBD2 scanner, but cheap Harbor Freight brand, not capable.
Didn't want to buy the gauge ... hook up where the oil pressure sensor is? I still think it's coming on because the filter get's clogged, but what else could it be?

 

[The Critic]

I don't think that orange RTV came from Toyota....someone's been there before.

This. I wonder if this engine isn't original to the car.