Car Sludge


Has anyone else faced the problem of car sludge in your engine? I have a 2003 Toyota Avalon and have had regular oil changes. An engine light came on and my car made a loud noise. I took to dealership and they notified me that my engine was sludged. They said I need a new one to the tune of $4,400. Or I could risk cleaning it for $700. I was told that the 2002 engines had this problem and they had warrantied these vehicles longer. I was told that my 2003 was one of the first with the engine that had been corrected. I only have 54,000 miles on this car. Toyota will not help me. I need advice. I think Toyota should have paid toward some of the costs.


Sludge is generally caused by oil changes that are not regular enough depending on the type of useage. In some extreme cases, even changing the oil every 3k miles may be borderline good enough.

How often do you have the oil changed and what type of driving do you predominantly do? Mix of city/highway or 90% city, etc.?
An engine light came on? Which one; red oil light, yellow Check Engine Light, etc.?


The problem with this specific engine is that Toyota in a attempt to make the engine run hotter to reduce pollution they reduced the cooling journals in the heads. This caused the engine temp to raise drastically…thus the sludge. Toyota is backing this up. Since the dealer isn’t helping try the zone rep. Do a google search and look at other Forums about how to complain to Toyota about this. 54k miles is way too short.

I’m not sure of what engines and years were effected, but it was only 2-3 years.

To help prevent this…use synthetic oil or change the oil more often. Synthetic is probably the best choice. It’s far superior to conventional oil in heat stress.


Can you define “regular” oil changes? On average, how many miles and how many months do you normally go between oil changes?


Can you define “regular” oil changes? On average, how many miles and how many months do you normally go between oil changes?

Regular is defined in the owner’s manual of the car in question. When I had a 1965 Sunbeam Imp it was 3,000 miles as I recall, maybe less. Now with a 2002 VW diesel, it is 10,000 miles. Neither would apply for severe driving conditions.



I hope you know that I am a major proponent of following the manufacturer’s maintenance schedule, including the “severe” service schedule, which is actually the appropriate one for very many vehicles. I am merely trying to determine the OP’s definition of “regular”, since that definitely impacts on the sludge problem.

Many years ago, I had the misfortune to drive to Florida in a co-worker’s car. He stopped on the NJ Turnpike for gas shortly after the start of our drive, and when the attendant checked the oil, he brought the dipstick over to the window and asked my co-worker, “When was the last time that you changed this mud”. (The oil was so viscous and black that it really resembled tar.) My co-worker replied something to the effect of, “Well, I do it regularly”.

By checking the door sticker, we determined that the last oil change had been approximately 18,000 miles previously! When I pointed out that this was not a good idea–whether on his Maverick or any other car–he looked at me like I had three heads, and he again told me that he changed the oil “regularly”.

As it turned out, he also did other maintenance on the car just as “regularly”–translation–never. The radiator sprang a leak in South Carolina as a result of rust perforation of the radiator. It turned out that the cooling system had never been serviced in the four years or so that he had the car, and what was in the radiator was a muddy mass of rust-colored water/coolant.

So, my point is that “regular” means different things to different people, and I was attempting to find out the OP’s definition of that word as it pertains to maintenance.


Changing it every time the engine seizes is “regular”!


By regular oil changes I meant, between the 3,000 check, recommended and 2 times it went to almost 5,000. That was the most I went over. That did not seem to be the issue with the dealership. They said that was regular oil changes to them. I had the last oil change with the dealership at 33,000 miles and then started with a Shell oil change co. I have all of my receipts.
The lights that came on the one time were the red oil light and I’m not sure of the color, but the engine light.


If you can’t get help from Toyota on this I suggest you try this product. Before paying out a lot of money for a possible needless engine swap or engine cleaning go to and order their product. You may even want to do this proceedure twice but hopefully one time will clean things up. After the engine has been cleaned out you can switch to Mobil-1 oil which hopefully will stop the sludge buildup problem.

If things are so bad that oil pressure is very low you may want to first replace the oil with new oil but exchange one quart of oil with one quart of transmission fluid. Run it in the engine for perhaps a couple of hundred miles to help clean up the engine and then use the Auto-Rx product with new oil to start the cleaning process.


It would be interesting to know if the oil level is where it should be.
JMHO, but if a red oil light was on followed by a loud noise then attempting to “clean” an engine is the one thing I would never consider. To some degree, the damage is already done. An oil pressure test could help verify how bad it is.
Must be a service writer talking again.

When the oil light comes on meaning no oil pressure it only takes a few seconds for the oil film to be scrubbed away on the crankshaft journals. Another few seconds and the overlay on the bearings is gone and this means a substantially shorter engine life even if one was successful in simply adding more oil and not suffering any knocking sounds.

I have no suggestions if Toyota Motor Co. will not come in and do a good will warranty for you. Just an FYI, but many times a problem may still exist no matter what the VIN number range. There’s a lot of politics involved in recalls, TSBs, and service campaigns.


Absolutely do NOY use Auto-RX. Anything that will make new oil in a brand new engine turn black is the source of the contamination, not the cleaner.

If you shut down the engine the minute the oil light came on, then the damage to the engine is minimal. Most of the sludge forms and collects just under the valve cover, on the head, and clogs up the return passages. If chunks break off, they can in turn plug up the oil pickup screen causing the oil pressure to drop and turn on the light. I would just get the engine cleaned and then switch to synthetic oil for the future. I would also use 10w30 and not 5w30, even when using a synthetic. Its more thermally stable. Do not use any additives, some of them can reduce the thermal stability of the oil.

I do think that if you go to the zone rep listed in your owners manual, Toyota will help you out. On these extended warrantees, the manufacturers will only allow the dealers to authorize repairs on a limited range of vin numbers to reduce abuse. The zone reps can approve those outside the vin range on a case by case basis. I think you situation will receive approval.


Check all the online websites, including and its forum. I know that Toyota has had major issues with a lot of complaints on the sludge issue and you might be able to find some relief if you have documentation on your side. You obviously will need the receipts for all the oil changes.


My '01 Lexus RX300 had the same problem last summer (with synthetic oil). The local dealership took the engine apart, cleaned it of sludge, and replaced a few parts. Car’s been running fine since then. Lexus picked up the tab because I mentioned to the dealer that I remember seeing a class action lawsuit against Lexus due to the commonality of this problem. Dealer took it upon himself to contact Lexus on my behalf.

I agree with MikeInNH: contact the local Toyota zone rep. or find another area Toyota dealer that will work to earn your loyalty (and money). If that doesn’t work and you can prove the frequency of oil changes in court (i.e., you have or can obtain receipts for all your oil changes and you did them every 3,000-6,000 miles), you may also want to have a lawyer send Toyota USA a letter of intent to sue.


Sorry VDC, I really was trying to prompt the OP. I know you know the answer.


No problem!