Options for oil add. to clean ring, piston soak?

[NattyBoh]

My wife's sentra started to burn some oil. Or loose it somehow. The cat was removed in anticipation of the known failure. Hers looked okay and I don't think that's the cause.

So she always drove slow, never really exercising the rings per-se. Always good on oil changes too. So I'm assuming maybe a stuck ring or carbon issue? What's good to soak the pistons and how do I do it? I've used Amsoil oil additive to clean inside but maybe something else is good too? I do have Another bottle here.

Running T6 seems to have helped consumption. Maybe add some ATP oil additive? Or start to run a UK oil?

 

[JC1]

How much oil is the car burning between OCI?

 

[NattyBoh]

Honestly never measured it, but it would be off the stick in 5k miles. Thiz is when I started to notice it. I don't know how much oil it takes to show up on the stick could be one quart

 

[UltrafanUK]

Make sure that the crank case vent system (CCV) is working correctly, as that will push oil past the rings etc.

After making sure the CCV is clear, then decide whether to use a high mileage oil or a can of stop leak additive. A major brand stop leak will work better than a high mileage oil.

Stuck rings are fairly rare in modern engines, unless the engine has been stored for a long time.

 

[NattyBoh]

Thanks she's been the only owner of it and km going to use it to commute now. It has 100k on it and always went to Valvoline. Now she said they used syn oil but I'm thinking there maybe be some sludge built up in the ring grooves/lands? I don't know.

The PVC is clear and new

 

[UltrafanUK]

Originally Posted By: NattyBoh
Thanks she's been the only owner of it and km going to use it to commute now. It has 100k on it and always went to Valvoline. Now she said they used syn oil but I'm thinking there maybe be some sludge built up in the ring grooves/lands? I don't know.

The PVC is clear and new



Sludge does not form in the rings, it forms mostly in the sump and other oil passages. Varnish forms where the oil is mixed more with air or overheated, mostly around the top end.

If you don't have any oil leaks, it might be worth using an idle only flush additive (Both Amsoil and Liqui Moly make good ones) just before an oil and filter change.
I would not bother doing a piston soak unless you know your engine type has a reputation for stuck rings.

 

[NattyBoh]

Thanks

 

[[RT] ProjUltraZ]

i would check for intake manifold oil leaks or other oil leaks. need to get under the car and wipe away whatever is already oiled and go back and see if new oil appears. or if it's internal look for exhaust color/smell. and go to a thicker oil like MaxLife

 

[OldEuroCarLover]

Originally Posted By: UltrafanUK
Originally Posted By: NattyBoh
Thanks she's been the only owner of it and km going to use it to commute now. It has 100k on it and always went to Valvoline. Now she said they used syn oil but I'm thinking there maybe be some sludge built up in the ring grooves/lands? I don't know.

The PVC is clear and new



Sludge does not form in the rings, it forms mostly in the sump and other oil passages. Varnish forms where the oil is mixed more with air or overheated, mostly around the top end.

If you don't have any oil leaks, it might be worth using an idle only flush additive (Both Amsoil and Liqui Moly make good ones) just before an oil and filter change.
I would not bother doing a piston soak unless you know your engine type has a reputation for stuck rings.


Will an idle only flush like Liqui-Moly do anything to help with a piston ring issue? I have the M54 BMW motor, which does have a reputation for stuck rings. I'm planning to do a piston soak, but I might use the Liqui-Moly flush as well.

 

[[RT] ProjUltraZ]

i thought liquid-moly was a friction reducer. didn't know about a flush. LC20 would help carbon build up but might increase oil leaks. that's what I would do, lift the car wipe everything esp the lower half, change oil add LC20, go back in 200 miles and look for oil leaks. if none then you know its not external at least. and go on bimmer forums and see what others do

 

[OldEuroCarLover]

Originally Posted By: [RT
ProjUltraZ] i thought liquid-moly was a friction reducer. didn't know about a flush. LC20 would help carbon build up but might increase oil leaks. that's what I would do, lift the car wipe everything esp the lower half, change oil add LC20, go back in 200 miles and look for oil leaks. if none then you know its not external at least. and go on bimmer forums and see what others do


This is what I used: https://www.fcpeuro.com/products/engine-oil-additive-500ml-can-lubro-moly-lm2037

In the end, I didn't do a piston soak. I might before the next oil change. I performed a PCV modification which, knock on wood, seems to be working. But it's too early to be sure.

The motor has zero leaks. It's perfectly clean. All leaking gaskets have been replaced.

Thanks for the advice. I'd never heard of LC20 before. I'll research it a bit and see what I think.

 

[UltrafanUK]

Originally Posted By: OldEuroCarLover

Will an idle only flush like Liqui-Moly do anything to help with a piston ring issue? I have the M54 BMW motor, which does have a reputation for stuck rings. I'm planning to do a piston soak, but I might use the Liqui-Moly flush as well.


Yes it will help clean the oil scraper rings. I would be real careful about doing piston soaks during winter, cos it can cause difficult starting when cold due to loss of compression if the rings are badly worn. Carbon deposits in the compression rings help them function to some extent when worn or cracked, so if you use a powerful solvent that dissolves that carbon it can cause a loss of compression. Tends to be more of a problem with older diesels than petrol jobs.