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Full Version: Sludge in Oil Strainer
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mtc911
I’ve changed a lot of oil over the years but never seen this sticky oily smelling “sludge” I guess? Oil is not that old. Should I be worried? What causes it? The car doesn’t run hot. Good news is nothing metallic.
914Sixer
Never seen anything like that. Looks like tar balls.
PlaysWithCars
Never seen anything like that either. Do you know much about the history of the car? Did it sit for a long time? Could it be that this accumulated during a LONG slumber? Besides not being metallic, it also appears to be oil color instead of black like dirty oil that wasn't changed regularly.

You might consider draining oil, fill the crankcase with diesel fuel and let it sit for a while. Drain and repeat a couple of times. If its oil based the diesel will loosen up any that's left and flush it out. Afterwards put in oil, run the car for a little bit, then do another oil change to flush all of the diesel out.
wonkipop
i've seen this in a newish toyota and a subaru that the mechanic who works on my cars does regular servicing on. he believes its a growing concern and the theory is increasing stop start driving with engine never really reaching operating termps for long enough.
the covid lock down seemed like it might have had something to do with it as neither of the cars which he regularly worked on seemed to have this before.

too much cold running? not sure. there are articles out there in the motoring press about it at the moment. there is a couple of theories on it. perhaps it has increased due to people not driving their cars as much as they did during the pandemic restrictions. or perhaps it is to do with how oils are being manufactured and from what base stock.

its bad and you should try and get a flush cleaner through the engine with the oil change.
it can block oil passages. you need to get it out. have you popped the valve covers to see what its like in there? often its all through the engine.

mechanics usually call this a varnish deposit i think.
Superhawk996
Sludging is a real problem on short drive cycles where engine doesn't come up to temp. Likewise there have been some problematic engines from Toyota, Chrylser, VW, etc., that seemed prone to sludge.

https://www.google.com/search?q=toyota+oil+...=Ez3JLx9V2VkdHM

However, air cooled engines like T4 generally run much hotter than water pumpers that have had the sludgeing that has plagued cars noted above as a generalization.

Your pictures look sort of look like excess sealant debris if only becuase the appear more "drip" like. Are they solid or do they basically disentegrate if you push them between your fingers?

Sludge can and will kill engines so I'd try to get a borescope down into the case via the breather. Or, maybe up though oil drain plug and have a look around. As suggested above valve covers are easy to pull and a great 1st look.
Mikey914
I think that whatever it is it’s plastic.
If you look really close it has an amber color. Try taking a baby food jar pitting the samples in, adding in some acetone, closing and shaking for about 20 sec. I have a feeling you will see it’s true nature.
My guess is some type of nylon.

Looks like your strainer did it’s job.

If it is plastic, change your oil twice. First time drive it get it nice and hot, drain it as warm as you can (carefully), let it cool and check the strainer. You may have gotten it all, but just in case you didn’t last thing you need is for it to become lodged somewhere where it impedes oil flow.
mtc911
I can definitely easily "dissolve" it just rubbing between my fingers...it is not very tough at all - haven't tried the acetone thing yet but I will...this engine definitely has no trouble getting hot - like most 914's..so I dont think that is the issue.

I bought this car a couple years ago and the previous owner had the engine rebuilt and it runs great....have changed the oil a few times since I have had it...just never seen that stuff before

QUOTE(Superhawk996 @ May 16 2021, 08:43 AM) *

Sludging is a real problem on short drive cycles where engine doesn't come up to temp. Likewise there have been some problematic engines from Toyota, Chrylser, VW, etc., that seemed prone to sludge.

https://www.google.com/search?q=toyota+oil+...=Ez3JLx9V2VkdHM

However, air cooled engines like T4 generally run much hotter than water pumpers that have had the sludgeing that has plagued cars noted above as a generalization.

Your pictures look sort of look like excess sealant debris if only becuase the appear more "drip" like. Are they solid or do they basically disentegrate if you push them between your fingers?

Sludge can and will kill engines so I'd try to get a borescope down into the case via the breather. Or, maybe up though oil drain plug and have a look around. As suggested above valve covers are easy to pull and a great 1st look.

wonkipop
if it dissolves like that its unlikely to be sealant or a foreign body, but instead something forming in the oil itself.

what brand of oil is it?
and is it mineral oil or synthetic?

there has been some material published here by the main auto clubs suggesting that it could be to do with base oil stocks being used and in the case of synthetic oils, that some oils are being recycled as base stock for the production of "new" oil.
also suggestions that some companies may be marketing contaminated stock.
both suggestions i've read have been in relation to synthetic oils.





Jake Raby
At some point you've experienced an oil change that created a chemical reaction..
Have you recently changed oil brands?
mtc911
So, I changed the oil again last weekend after running a good bit and getting it nice and hot - Oil was very clean and nothing in strainer this time. I am going to run it a few more weeks and then change oil again and see what I get. That oil that I just removed with that oil change was liquid Moly which I have always had good success with.

The oil that produced the Sludgy "stuff" I believe was Castrol (Which I normally never buy but I was in a jam after doing some work and needed a quick change). I will not use that brand again'

I also had just started running higher octane fuel in it....I don't know if that adds to the mix or not.

The oil in it now is Valvoline VR1 Racing 20w50...will replace it back to Liquid Moly after next change.

Thanks for all the feedback and suggestions....will be curious to see what's in the strainer next time.
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