My wife's 1999 Toyota Sienna minivan has given us nearly 152xxx miles of fantastic service. The "oil-gel" (i.e. sludge) problem with this engine was well known, but I'd never encountered any symptoms, so I kept regularly changing my oil. Long story short, after fighting an oil leak for over a year, a mechanic finally identified the rear main seal was the culprit. I bit the $$$ bullet and had a rear seal replaced. About two weeks later, we lost oil pressure to the engine, but was able to stop the vehicle before damaging anything. Continuing this long story, shortened, after dropping the crankcase pan, the "oil-gel" problem was discovered...most likely the cause of my rear main leak, too. The sludge/carbon had completely blocked the oil strainer (see pics attached). The mechanic removed as much of the sludge/carbon from the crankcase side by brushing, scraping, and air pressure. The mechanic recommended dumping the car because he didn't know what damage may have happened and it was certain this problem is not going away. The car has always run great, but I have noticed higher than normal oil usage. I've sent all my associated repair bills and documentation to Toyota's Oil-Gel Settlement department, but have not heard ONE word yet. In the meantime, I found many references to Auto-Rx and sludge, so I thought I'd give it a shot. I'm in the preliminary cleanup phase. I'm posting another topic on a 1999 Corolla that has the same problem.
That doesn't look like it will be that much of a challenge for Auto-Rx. Just don't score any of the sludge under the valve covers. Leave everything that is still intact - alone. If you breach the layers ..it leeches and can get undermined and break off in chunks. Just let Auto-Rx do its job slowly. It will be fast enough with all that material/surface area involved.
Don't get too disturbed if you hear valve clatter at various stages of cleaning.
You may need 3 treatments to get it all clean ...and surely the maintenance dose for continued long term cleanliness.
Unfortunately, I did not pull the valve covers on the Sienna when the sludge was found. Also, I had the valve cover gaskets replaced at ~138000 miles at my mom and pop shop and the mechanic had not mentioned to me any problem. I am pretty sure he would have told me if he found carbon or sludge.
Frank, I am following the "heavy sludge" directions from the web-site. So far, I am about 700 miles into the first cleaning cycle. I have noticed little things that indicate the cleaning is in progress....(1) I seeing oil actually laying on the oil fill baffle, which I don't think I'd seen before. Previously, I'd find it dry with some small deposits of rust colored paste. (2) I am seeing a very slight oil seepage, which I expected from cleaning the sludge from seals.
Don't be surprised if you start getting CEL during the clean phase. Both vehicles I'm running ARX in both got CEL with O2 sensor errors. I replaced both O2 sensors and still had these errors. ARX continued cleaning and the errors cleared themselves.
The clean up phase is complete for the 1999 Sienna. I am attaching a picture of the filter cartridge paper after 1250 miles and after 2500 miles. This car is now nearing the end of the rinse phase.
This is what Frank has been informing customers the rinse phase is where you will see what Auto-Rx will do. I think the rinse phase is the most important part of the Auto-Rx program but that is just my opinion.
Thank you for the photos and using Auto-Rx it is a great product.
I would expect to see a couple more filters in the same condition or worse during the rinse phase. I would likely change out the filter at about the half way point of the rinse or 1500 miles. After the completion of the first full rinse phase 3000 miles, I would start cleaning application number 2. Looks like you are making good progress.
