I have about $170,000 mi on this car. When I bought it about 4 years ago the maintenance record was great on it. They replaced the alternator, timing chain, oil change was regular, body in great condition. I think I have maybe two speakers that are blown which still sounds good when the bass is all the way down. The Volume on the radio sporadically stops working, I need four new tires. Besides that everything is great the car runs really smooth. I really love this car and I don't mind fixing all these issues but the big problem is it burns oil , And I most likely have carbon buildup.
If I sell this car I could probably get about 6K for it, But I would have to put in another 5 or 6K to get a good car. I'm sticking with Lexus. Is it worth it rebuilding the engine since I got both carbon build up and burning oil ? If I sell it I want something with equal luxury and smoothness. Without spending over 12K and I don't want another car with 160,000 mi on it . Cars are expensive right now

 

You do not need to rebuild your engine to deal with carbon issues. If you manually clean the carbon through the intake ports on the head you will be fine.

If your handy at working on engines then cleaning the carbon yourself is not difficult. Just time consuming! There are shops that can do walnut blastings, mostly mini cooper and bmws have this issue. You should be able to find independant shops in your area that do walnut blasting. You could also do a piston soak, this will help loosen up the rings. Also concerning the oil consumption, how far are your oil changes? If your changing oil at 5,000 probably better for you to switch to 3,000 mile oil changes. This will help clean engine internals.

Theres videos a member was kind enough to make, which shows the process of how to do the carbon cleaning at home. Hes a bit to meticulous so you do not need to go to this extreme in cleaning. Just cleaning the bulk of the carbon and sufficient imo. He has other videos aswell that may help you. When you are done, I would toss in fresh spark plugs that are original denso purchased from a reputable seller. As there are a lot of fake plugs out there.

 

I’m not experienced with the carbon issues on these engines. But if it’s happening in lubricated areas, (ring packs, etc), be aware Valvoline has a remarkable new additive chemistry in an oil called “Restore and Protect” that is showing real results. Google it and check it out. I’m putting some in my SUV shortly, which is known to have serious oil ring and drain hole issues, and likely the GS, too.

I thought the main oil issue w/these was low-tension rings, not carbon build up? But I’m not as versed on these engines (trying to get up to speed now) so maybe I’m wrong on that.

hey @ibidu1 - what is the preferred plug for a 350? The existing plugs went in 25k miles ago by another mechanic; I’m not sure what type. I’m going to pull one tomorrow and check.

 

My opinion on the issue with the oil burning is delaying oil changes. Many people think toyota engines are like modern engines that can handle 6-10,000 mile oil changes. Toyota/Lex keep there engines simple, and basic there engine designs have not changed much since the 1990's. When oil changes were common at 3,000 miles and used dino oil. The oil passages in the pistons ring gallery are to small to handle 10k oil changes. The longer you delay an oil change the more varnish, sludge, crud adds up in the small. Me I run my oil at 3k, I do a lot of city driving. If someone only ran highways then up to 5,000 should be fine. Also many people think they have oil burning issue, but fail to look for external oil leaks on the engine. Our engines are old, so seals gaskets dry up and leak. A person has to raise the car in the air and search for leaks like valve covers, front crank seal, front timing cover all these are common for leaks.

I have seen that valvoline oil, looks promising, I wouldnt expect miracle results from it because oil companies can only put so much detergents in an oil without damaging engines oil seals.

For plugs Denso 3473 iridium long life or oem FK20HBR11 only plug. The engine is sensitive to plugs!

 

I have 2 ML front speakers for sale