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Cleaning engine oil sludge/gel out of engine

58K views 31 replies 12 participants last post by  Duncandogster 
#1 ·
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?

Thanks for all your help.
 
#3 · (Edited)
Synthetic

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.

Never heard of one sludging on synthetics.

Regards,
Mike
 
#5 ·
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.

http://www.tegger.com/hondafaq/sludge/cleaning_sludge.html
 
#7 ·
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.
 
#8 · (Edited)
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.
 
#10 ·
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.
 
#11 · (Edited)
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?
 
#12 ·
And do what Qslim said in a previous post. Although i have a question, why would you buy new valve covers?
Redesigned baffles in valve cover to make PCV system work more effectively
 
#13 ·
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.

Any help is appreciated. Thanks
 
#14 · (Edited)
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.
 
#15 ·
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.

N.E.O.
 
#16 ·
Unless you remove all four camshaft, you won't be able to get to the buckets or the valve springs......
Isn't the O.P. doing that? Wait, to the O.P., how far do you want to strip the engine down?
 
#17 ·
Taking the oil pan off is real easy. You'll see it when you're under the car, it's unobstructed and lined with 10mm bolts. Remove the bolts and knock it with a mallet a few times to loosen the sealant, and you'll be able to pry it off.

The only other thing here that I would strongly recommend is replacing the valve covers. Toyota redesigned the PCV and baffles as a response to this sludge problem, so it would make sense to put a new set on.
 
#18 ·
Thanks for the suggestions. I probably won't pull the head off. I really don't want to unless I absolutely have to. I scrubbed the front valve cover and camshafts and got them pretty clean. I'm probably just going to try and do the back the same. And I'm gonna pull the oil pan. I might need some questions answered this weekend.

Few more questions.

Where is a good toyota parts store (online/in person) where I can get the new valve covers for a cheap price?

Since I've had the car, if I step on the gas to get on it, it sounds like there are marbles rattling around in my engine/cat converter area. What is that?
 
#20 ·
future solution

When you get done with this project, you might also just think of sticking to one brand of oil. incompatibilities may add up over the life of the vehicle. Castrol GTX is my suggestion... I've used it ever since I've owned imports 14 years ago...
 
#22 ·
When you get done with this project, you might also just think of sticking to one brand of oil. incompatibilities may add up over the life of the vehicle.
I strongly disagree. I would argue that using a half dozen or so different brands exposes the engine to many different detergent packages, resulting in a cleaner motor. Here's what my '92's 3VZ-FE looked like under the valve cover at 273K miles a few months ago. And I use whatever oil is on sale when I walk in the door. I change it every 3K miles.

 
#21 ·
Does anyone use Valvoline XLD, or is Castrol GTX the go? Only asking as the service manual for the 2nd gen 3S-FE camry recommends XLD, while most people around here use GTX for the same car.
 
#27 ·
Oh come on. Let's not get into the neverending argument of oils. I swear on auto message boards, no one can share their personal views on religion, politics, or oils because it just snowballs.

Should I just go to Napa or Advance to get the valve covers and plugs? Or is there a quality online site?
 
#29 ·
Seriously. Just put some oil in your engine, for christsakes.

For the valve covers, I would really recommend factory, simply because toyota redesigned the baffles and pcv breather to help counter the sludge issue. As for online sources, I dunno. Call the dealer, get the part # for the updated covers, then google the part #.
 
#32 · (Edited)
There are many resources online that have the lubricity and heat/viscosity indexes for different oils. Lucas and AMSoil and Mobile 0-30 are my go to for gas turbo engines and problematic sludge problems. They have the best detergents (cleaning properties) and are extremely resistant to coking and sludge.

With a non-turbo engine that is sludging but not yet at the chunking stage, I would use havoline 5-30 with a pint of type-F transmission fluid for 3 or 4 changes at 1500-2000 miles (or when oil looks dirty), and then switch to AMSoil or Lucas when the oil starts staying clean looking clear for 2000 mi..
 
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