My 1996 Camry wagon with V-6 and 90,000 miles was in for a new timing belt and to replace leaking valve cover gasket. Mechanic commented that there was a huge amount of sludge evident and might explain the ticking noise I’m hearing in the engine.
He suggested either getting the engine “motorvac’d” or adding 5 weight oil with quart of Marvel Mystery Oil and running for 20 miles, then changing back to standard weight oil. Do either of these suggestions sound like they’ll work?
There are products at the parts store that you can purchase to clean out the lubrication (oil) system. I’ve never used “Seafoam” but that seems to be the most recommended one here. That you can do yourself and it’s better than a home remedy like 5W oil and marvel mystery oil.
Follow the directions to the letter.
There is a concern with mid 90’s Toyota V6 engines and sludge buildup in the engines due to high engine temperatures and poor drain back of engine oil into the oil pan.
Running some sort of cleaning product through the engine might release all that sludge, but ultimately, I would recommend after you get the engine cleaned out, that you no longer use conventional oil in the engine, and use a good grade of synthetic, to lessen the chance of sludge buildup in the future.
BC.
I followed this discussion a few years back and seem to remember chemical cleaning didn’t do much in these engines. MMO does work very well on sludge because of one ingredient that is a solvent. I love Toyotas, but this engine was a big mistake.
Long ago, we’d take off the oil pan, scrape off the sludge, then put it back. If you do that first, then put in some cleaners and try to do the top with them. I know that CD2 makes a detergent oil additive.
"Long ago, we’d take off the oil pan, scrape off the sludge, then put it back. "
And what did they do to you when they found out? 
One thing you DON’T want to do is remove the sludge FAST…especially if you have a LOT of sludge in the engine. I do NOT recommend the Motorac type method. Using the 5 weight oil and Marvel Mystery oil is good…but that may be too fast also.
I recommend you next oil change to replace one quart of oil with one quart of Rislone and change the oil AND FILTER after 1000 miles. Then repeat this two more times. After the 3rd time the sludge should be gone or greatly reduced. Then just replace oil with normal oil.
Because of this engine I HIGHLY recommend that you decrease your change interval…or switch to synthetic. Do NOT go more then 3k miles if using regular dyno…or 5k with synthetic.
Thank you all for your suggestions and the amusing sidebar comment from Joseph Meehan.
Sounds like the general theme that incoporates most of your comments (Except Joseph’s) is to use some kind of chemical cleaner, use a method that cleans out the sludge slowly, use synthetic oil in the future, change oil at a shorter frequency and stay away from Toyota’s 6 cylinder in the future. (And if not too much of a headache, drop the oil pan and clean it out.)
use synthetic oil in the future, change oil at a shorter frequency and stay away from Toyota’s 6 cylinder in the future.
Toyota only had this sludge problem for 3 years. Their new engines are NOT experiencing this problem. In fact I don’t think y our engine falls in this category. All engines are subject to sludge buildup if NOT properly maintained.