Removing Sludge to Prevent Engine Failure?

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Hello,

I recently purchased a 2004 Toyota Corolla with only 85,000 miles on it. I bought it for a good price sight unseen and it runs great. I replaced the spark plugs, water pump, thermostat, coolant, brake pads, rotors, etc. My goal for this car is to have a reliable gas saver as my only car.

Here is the problem, when I went to change the oil and took off the fill cap, I noticed some sludge. When changing the oil, it came out very dark, pretty much black. I have no idea what kind of oil it was but I'm assuming cheap stuff. So I put in Penzoil High Mileage 5W-30.

So what I've decided is to pull the valve cover and oil pan, clean it as best as I can by hand and do an oil change after about 100 miles, then maybe 500 miles, etc?

The question is, with all of the above considered, what would be the best way to go about removing the sludge? I'm driving to move cross country at the end of the year and then will be using the car to get to and from work.

Thank you!
 
Originally Posted by 04CorCar
... what would be the best way to go about removing the sludge? ....

Disassemble engine, clean and check for significant damage.
Rebuild/replace anything showing noticeable wear.
 
Welcome to Bitog! First off, its an extremely reliable car. If I were in your shoes, I wouldnt of been as extensive as you. My 07 with 170k miles is still on its original water pump. Regardless thats another story. How bad was everything under the valve cover? How much oil drained out? These engines are easy on oil.
How have you confirmed its sludge? Show us pics of the valve cover and im sure some members can provide you tips and insight depending on level of sludge. Good luck!
 
Sorry about that, I meant the best way considering my plans above as for just removing the valve cover and oil pan. Meaning, should I put some type of engine flush in it before I take both off and/or multiple short interval oil changes?
 
Originally Posted by Rolla07
Welcome to Bitog! First off, its an extremely reliable car. If I were in your shoes, I wouldnt of been as extensive as you. My 07 with 170k miles is still on its original water pump. Regardless thats another story. How bad was everything under the valve cover? How much oil drained out? These engines are easy on oil.
How have you confirmed its sludge? Show us pics of the valve cover and im sure some members can provide you tips and insight depending on level of sludge. Good luck!


Thank you, they sure are. I owned an 04 before this and it never missed a beat.

Actually, I haven't pulled the oil pan or valve cover yet. I just know it can't be good considering what I saw under the fill cap AND how the oil drained out. I'll definitely be removing the valve cover once I get the gaskets in to assess how bad it really is but I'm not totally sure I'll be removing the oil pan yet, however I probably will since I can.
 
I would buy Supertech or NAPA synthetic oil and change at 3K intervals until it does not look so dark when changing. Forget about pulling the valve cover. Looking down the oil fill is not a good indicator. The goal is to remove or at least not let it get worse. Some sludge does not kill an engine. Its only when it starts to prevent the oil from returning to the oil pan that there is an issue.

And forget about an oil flush also.
 
Originally Posted by Donald
I would buy Supertech or NAPA synthetic oil and change at 3K intervals until it does not look so dark when changing. Forget about pulling the valve cover. Looking down the oil fill is not a good indicator. The goal is to remove or at least not let it get worse. Some sludge does not kill an engine. Its only when it starts to prevent the oil from returning to the oil pan that there is an issue.

And forget about an oil flush also.

I agree. You may cause more damage by messing with it.
 
Get the high mileage oil out of it now, unless it was burning oil or there was a leak, and consider that your safer alternative to a flush, to just do that very short oil change.

I mean I would at least drive it up to temperature to work it around the engine and get the detergent action going if you JUST changed the oil, but otherwise HM oil does more harm than good for an engine that doesn't need it.

After that, do a 3K OCI then 5K or yearly whichever comes first.

Was the sludge in the engine or only built up on the back of the cap? Back of the cap is common even if not built up in the engine, but if the PCV valve hasn't been replaced recently, do that.
 
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If you're intent on removing the VC's and pan (for whatever the reason, and that's entirely your choice) I would run a good flush through the system. A single flush is not going to hurt anything and there's no better time to do it since you're replacing the pan and valve cover seals already. A flush like Motor Medic will not only clean up sludge but go work on varnish.

Following the flush, I'd run something like Castrol Ultraclean for a 3k oci and then switch back over to your lubricant of choice.

Just my 2 pennies...
 
Easy, change the oil and filter, then when it starts to look a little dirty, change it again, repeat as necessary. One trick I use is before reinstalling the drain plug is to dump about 20 ounces of fresh oil into it and just let it drain out to clear any additional old dirty oil. I put my last oil change up on Rhino-ramps to help the oil to pool at the back of the pan near the drain hole, and then seemed to get more of it out when the fresh oil drained through. Your results may vary.

I'd say if your going to replace the valve cover gasket, go ahead and clean that out, but the oil pan probably shouldn't be disturbed unless there is a leak.
 
Originally Posted by Dave9
Get the high mileage oil out of it now, unless it was burning oil or there was a leak, and consider that your safer alternative to a flush, to just do that very short oil change.

I mean I would at least drive it up to temperature to work it around the engine and get the detergent action going if you JUST changed the oil, but otherwise HM oil does more harm than good for an engine that doesn't need it.

After that, do a 3K OCI then 5K or yearly whichever comes first.

Was the sludge in the engine or only built up on the back of the cap? Back of the cap is common even if not built up in the engine, but if the PCV valve hasn't been replaced recently, do that.


Where'd you hear that load of bull pucky?.. and have you considered letting XOM, Chevron, SOPUS, Warren et al. know about this revelation of yours???.. because they, the guys who actually formulate the stuff, seem to think differently. And let me know when you're starting your class action suit against the biggies...cuzz I need a new boat!...‚
 
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The trick to a neglected vehicle like this is simply to use it and start maintaining it properly. I would get an oil change...and keep changing it every 5,000 miles. The sludge will clean itself out gradually which is what you want. Try to do it fast and you are going to plug an oil galley etc and cause damage. DONT MESS WITH IT.

Also make sure what you saw under the cap wasn't simply a milky sludge due to around town driving and condensation in the oil.

I had a totally sludged and noisy GM 4.3 that I got with just over 100k on it. By changing the oil every 5000 miles it cleaned itself out completely by 200k and it honestly ran fine until beyond 500k. No im not exaggerating.
 
Originally Posted by Doublehaul
The trick to a neglected vehicle like this is simply to use it and start maintaining it properly. I would get an oil change...and keep changing it every 5,000 miles. The sludge will clean itself out gradually which is what you want. Try to do it fast and you are going to plug an oil galley etc and cause damage. DONT MESS WITH IT.

Also make sure what you saw under the cap wasn't simply a milky sludge due to around town driving and condensation in the oil.

I had a totally sludged and noisy GM 4.3 that I got with just over 100k on it. By changing the oil every 5000 miles it cleaned itself out completely by 200k and it honestly ran fine until beyond 500k. No im not exaggerating.

Then there's this 👆 approach which is 💯% tried and true. Some oils are known for their exceptional detergency. Run one of those for 5k oci's from here on out and you'll eventually get that "clean" engine you're looking for. (-except it won't do much for varnish, for that you're gonna need solvents)
 
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Well, lots of varying opinions here I see. I appreciate all the input very much.

It seems that it may be in my best interest to leave the valve cover and oil pan gasket alone and just go on with my oil changes.

Thank you everyone, I'm sure it will work out!
 
I just used some Seafoam on my Mondeo with 141k on the clock. It's not the cheapest stuff to buy here in the UK (16oz bottle cost me £15).

I changed the oil out for a conventional 15w40 HDEO and a Fram Extra Guard filter. The car takes ~6 litres of oil so required 6oz of Seafoam. I took all the spark plugs out and distributed 7oz of Seafoam into each of the cylinders forcing it to run past the piston rings. I decided to add the extra Oz as some was about to hang around and not make it into the oil. I then ran it for ~300miles and drained the oil which was pitch black like diesel oil. Clearly some cleaning had taken place but nothing noticeable through the filler hole. It certainly hasn't touched the light varnish that I can see on the cam bearing caps.

I've swapped it out for Castrol Magnatec 10w40 which I will run until mid December. At which point I want to replace all of the valve cover gaskets so I will have a chance to properly see what it looks like under the covers.
 
Before I go through all of that I would use a bore scope inspection camera and have a look. I bought one for under $30. It can go down the fill tube or into the oil pan via the drain hole. It will eliminate any guess work. Based on my findings I'd determine the next step if any.
 
Just use a High detergent diesil oil 5w30 and change when it starts discoloring , if you do have a lot of sludge, you don't want it to break down and come loose all at once.
 
Make sure that it is actually sludge that you're seeing and not just because you removed the oil filler cap. Many Toyota valve/cam covers have a baffle/plate under the oil filler cap that gets kinda "sludged up" looking while the engine is totally fine. It could just be the baffle/plate looking kinda crusty/sludgy. Pull the valve/cam cover and know for sure!
 
I vote for just driving it. Change the oil every 5k and call it done. A deposit isn't the end of the world; anything that has been built up won't get worse now that it's getting good oil on a short OCI.
 
I had a friend closing a wrecking yard, helping him pull engines/transmissions. Many of the cars had multiples of 100K miles and a look under the oil cap was pretty scary. I am of the opinion that sludge not circulating does not hurt a thing. If you disturb it, then you can block things. Some of the valuable cores we disassembled, cleaned and sold the pieces.

So, just change oil AND FILTER often, like every 3K, for a while. If you slowly dissolve sludge from the outer layers down, odds of a chunk breaking loose and blocking something are low. I would just leave it alone.

Rod
 
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