I have a '97 Avalon with 103000 miles. When we bought the car a year ago we thought we got a great deal on a great car. Well a few months after we bought the car, on startup the car would smoke and as the months went by, it got worse. To make a long story short, we bought one of the 3.0l that is prone to oil gelling/sludge. Unfortunately the recall only goes back 8 years from original purchase so we are screwed. I tried AutoRX. It worked well. Took the check engine light off and stopped the misfiring. But it is too far gone for more AutoRx. I took the valve cover off and I new it would be bad but didn't think it would be this bad. Looks like someone poored a big helping of oil oatmeal all over. I scrubbed up the valve cover, what would you recommend to further clean the engine? How would I go about taking off the oil pan to get to the oil screen? Is there a thread on replacing the oil screen?
It might also be time to change to synthetic oil. Don't laugh, I use the stuff at Wal Mart, I think it's Penzoil if memory is correct. It's a whopping $3 a quart. This car has been on it since birth. When I changed the valve cover gaskets, everything was beautiful and clean.
The only sure fire way to clean all that sludge is to remove the heads drop the oil pan. It's a lot of work and it's extremely messy. It's also pointless to replace the oil screen without completely cleaning the sludge out of the engine, because there will always be the threat of clogging it up again and starving the engine.
Here's a writeup I did years and years ago when I was still with Toyota, just to give you an idea of whats involved.
I did switch to synthetic a couple of oil changes ago. Hope it helps. Took the valve cover off this weekend and it looked about half as bad as the pics you have in your link, Qslim. Tons of goo but your pics are about twice as thick as mine was. Cleaned the whole valve cover and inside out. Filled her back up with syn and it has helped for now. I just hope it doesn't resludge or the sludge clogs the screen.
Is that all you did Qslim was to thoroughly clean the valve cover, springs and such and cross your fingers? I hope it helps.
P.S. I did notice when I was in there that it still has its original plugs. The Japanese sure can build 'em but this one sure couldn't take care of one.
You know you have another valve cover in the back that is just as dirty, right?
For the sludge jobs, the heads, springs, and associated hardware get soaked in a can of carb cleaner. That gets all the crap from the little nooks in the head. The oil pan and sub-pan just get cleaned off with a brush in a parts tank, and the oil strainer gets replaced. The valve covers themselves get replaced as well, as the new versions have a different breathing setup on them (Toyota I guess traced part of the problem to poor PCV characteristics).
At this point, all of the gaskets are usually hard and brittle, so a new gasket kit gets put on. This goes for the stem seals as well. Also, a compression test is done before tear down, and the piston rings replaced if needed.
If the sludge is just gooey, then you might be able to get away without removing the heads. In any case, they need to be cleaned out and the oil pan needs to be removed. When the sludge starts getting chunky (like peanut butter) is when you run the risk of clogging the strainer. If you aren't there yet, a manual cleaning on the top and bottom followed by several treatments of BG MOA (or the like) and frequent (500 mile) oil changes might clear it up.
I'd also recommend changing the valve covers, too. If I remember right, they're only about 30 or 40 bucks.
It's been a while, but I think I was getting somewhere around 15 hours for a sludge cleaning, and that's without taking the pistons out to do rings. I think a couple hundred bucks in parts and 15 hours or so of labor is about right.
It's definitely not worth paying a mechanic to do it for you; that'a if you know what to do. Let's just say you know a guy who can do it for you for $40p/h labor, that's going to be $600 in labor alone.
And do what Qslim said in a previous post. Although i have a question, why would you buy new valve covers?
Okay. Thanks for all the great info. Yes, I did know there was another valve cover. It was gonna take a little more time than I had to take that one off on Monday.
This weekend, I plan on taking both valve covers off, changing the plugs, cleaning out the back valve area and cover. I found a great write-up on here on how to take the back cover off so I'll be okay on that.
What else should I probably do? I'm not going to change the lifters and replace the springs and all that stuff, just too much time for my '97, but should I take the pan off and replace the screen after cleaning? How would I do that? Does anyone know a good write-up for that? I will take pics and post up everything I do; as I wish I would have for the front valve cover.
This weekend, I plan on taking both valve covers off, changing the plugs, cleaning out the back valve area and cover. I found a great write-up on here on how to take the back cover off so I'll be okay on that.
What else should I probably do? I'm not going to change the lifters and replace the springs and all that stuff, just too much time for my '97, but should I take the pan off and replace the screen after cleaning? How would I do that? Does anyone know a good write-up for that? I will take pics and post up everything I do; as I wish I would have for the front valve cover.
Any help is appreciated. Thanks
Would be best if you got yourself a service manual. You don't HAVE to get a new screen, might be able to get away with just thoroughly cleaning it. Don't have to change the lifters or spings, just take them out for a good head and valve clean. Valves will most probably be carbon-y. To get the pan/oil sump off, you need to jack the car up and put it on stands or have it on a ramp that high enough so that you can fit under it. Then un-bolt the oil sump and it should come straight off. Then you'll see the oil pickup/sifter, and take that off.
Unless you remove all four camshaft, you won't be able to get to the buckets or the valve springs. Cleaning it this way works; however, there is also a chance of knocking some of the sludge loose, which may not drop all the way down to the bottom of the lower pan for you to remove. Those loose stuff might one day get down to the bottom and plug up your pick-up screen.
If the engine smokes with you first start up in the morning, or after it had been sitting, you will probably need to replace the valve seals, just cleaning the sludge out is not going to stop that.
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