engine sludge

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Jan 6, 2004
El Paso TX
I just purchased a used Toyota Avalon with the 3.0 V6 I'm reading a lot of posts on different forms on how these engines are prone to sludge buildup. The vehicle had 20000 miles when I purchased it and no maint records. The oil was honey colored when I had it changed at the Toyota dealer. I've since put a 1000 miles and the oil on the dipstick is clean no discolor that I can tell. Does this indicate that the engine is free of sludge? Any opinions?
If you had sludge you would see some indication under the oil fill cap and the dipstick. Doubtful that you do with only 20000 on the vehicle. If you keep the oil changes 4000 or 4 months with dino or 6 months 6000 miles with synth you should be fine.

Daily Drives:
-2003 Toyota Tacoma PreRunner XtraCab, Impulse Red, Peppy 2.7 Liter 4 Banger, Running Mobil1 Synthetics SS 5W-30.
ODO 7100 Miles.
-1995 Toyota 4-Runner, Evergreen, 3.0 V6, Running Mobil1 Synthetic SS 10W-30.
ODO 83110 Miles. (Switching to GC next)Nope sticking with M1.
Thanks for the reply Amkeer. Checking under the oil cap I find a metal baffel which looks like it is covered with a hard crusty material. I cannot directly view any of the valve train. Not sure if the crusty material is normal I hadn't noticed it before. The dipstick appears clean.
That's the coating they put on the baffle.My 02 Sienna has the same thing.
The sludge issue was primarily in the 1999-2001 V6 Toyota engine. You don't state what year your vehicle is.

Also, check with the dealer, they extended the warranty on the engine if this condition should occur. As always, keep your oil change receipts.
I have and 03 Sienna and a 99 camry v6. I have used Mobil1 5w-30 in the Sienna since new and it has 20k miles. No problems that I can detect. In he 99 camry I bought the vehicle in the blind at 80k miles. I immediately started using Mobil1 5w-30. There is no discloring on the stick and there is the black color at the oil fill. I did change the PCV valve (easy) and the old one was clean of any deposits. Just to be at piece of mind I am opening the valve covers on Saturday and taking a look on the camry. If there is anything I am using AutoRX. I too read many articles on the sludge and believe there is an issue. However, I see many Toyotas in the year range still operating fine. There has to be a determining factor somewhere. Just use synthetic and change it. At 20k I would be suprised of any sludge.
I want to thank you all for your input. It is a 2002 model and I changed the oil myself yesterday. Nothing floating around I think the engine is clean, but I will have it tested next oil change. This site has a lot of great info and you guys are very knowledgeable, thanks again
You know I dobt you have an issue but you never know how the previous owner cared for it. $24 for a single bottle of Auto-Rx is cheap insurance against a realy sludged up engine.

If it were me I would order one bottle. I would wait until you were within 1500 miles of your next oil change. Change the filter and add the bottle of Auto-Rx. I would drive it another 1500 miles and change the oil and filter back to what ever you are useing. If you decide to use conventional oil 3000 mile interval is hard to go wrong with.

The problem is that 5W30 conventional oil is not robust enough to stand up to the shearing forces and heat this engine produces for the recomended 7500 oil change interval. Conventional 10W30 hold up much better and at 3000 mile intervals. Synthetics are always a good idea if you plan on owninf the car for a while!
Just finished removing the valve covers from my 99 camry v6 with 80k. I thought from all the posts I would find sludge. I was suprised to find very little of anything. There was very light varnish and about a dimes would of a black loose material primarily at the drain opening (is that the sludge). I was satisfied as I had no previous history. I am planning on an AutoRx treatment anyway to help on the varnish. But certainly no emergency. The baffle that is under the oil cap is NO indicator of sludge on the vehicle and the oil passage from the baffle is small. The look inside the cap looks worse than inside the cover. I do plan on using 5w-30 Mobil1. The front valve cover is about an 1-2 hour job and I also drained some coolant to allow the top radiator hose to be removed.....the rear is another story!

Could you be talked into either Mobil 1 10W-30 or the new Mobil 1 5W-40? Either will give you better protection toward the end of your oil change interval, and likely more protection in your climate with the 5W-40.

The varnish that is a problem is a hard brown deposit with some evident thickness to it. The brown stain on cast aluminum is no problem, and probably can't be removed by anything.

I'd agree with Ken on this one ....

The increased detergency of the CI-4 rated, 5w-40 will help clean out any pre-existing engine deposits. It's probably a bit too thick to get the best performance out of this engine however. The friction modified, 10w-30 would be my choice for long term use if you are running Mobil 1 in any Toyota engine. For ambient temps < 32F, I'd experiment and also test their 0w-20; supported by oil analysis after 5000 miles to check on bearing wear.

I have 2 of these Toyota engines, both the v6. All the manuals say 5w-30. But if I can get better cleaning/protection I am for it. I am trying to get past all the hipe about what to use. In Mississippi the winter is rarely below 20 degrees and the summer is long days above 90 degees. Is the thought that a different viscosity would be a benefit? I question my protection in summer, city driving at temperatures above 90 with 5w-30 Mobil1?
If you can't see into the valve cover due to the baffles, check the dipstick above the normal oil level for varnish.

Prob. OK after only 20K miles, especially since new oil didn't darken immediately.
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