Anyone done engine flushing?

[GZilla]

Bought myself liquimoly engine flushing liquid.
https://www.liqui-moly.com/en/us/pro...L9efD_BwE#2037

Was wondering if it’s worth doing it on a 160,000 mile M62 motor with a bunch of varnish and sludge? I managed to remove all of the black sludge manually with a plastic scraper when the valve cover was off. I’ve read some positive and negative things about doing this and would like the feedback or suggestions from everyone here.

[MotorMouth93]

That stuff might work on sludge but it does absolutely nothing for heavy varnish. I did it religiously with every oil change for a while but gave up when I saw no noticeable differences under the valve cover after 3-4 applications. My engine was mostly just varnished though with very little sludge.

[effduration]

There has been quite a bit of discourse on this topic among the E46 crowd in the he M54 engine.
This method has been shown to clear sludge and carbon and to reduce oil consumption from clogged rings.

See post# 4
https://www.e46fanatics.com/threads/...ption.1259657/

[Jason5driver]

I have used the Liqui-Moly stuff , and the Amsoil engine flush as well .
I don't know if it is doing much , but I try ... lol .

[MtnGn]

Yes. I add the detergent around 500 miles out from an anticipated oil change. It seems to help with ticking lifters. My E39 sits allot, particularly during winter months, and if Im not diligent about the occasional engine start the lifters dry and stick; why I started.

[jp5Touring]

Tried Liqui Moly once . I wasn't all that impressed or my motor wasn't as dirty as I thought it was.
New Castrol every 5k and maybe a quart added and were good.

[GZilla]

That stuff might work on sludge but it does absolutely nothing for heavy varnish. I did it religiously with every oil change for a while but gave up when I saw no noticeable differences under the valve cover after 3-4 applications. My engine was mostly just varnished though with very little sludge.

Oh man, I do have quite a bit of varnish inside. Looks almost like rust. I might just use the engine flush for the little bits of sludge I saw and then drain it out when the car is warm to let it flow (bless my hands from being burned). If I do it, should I remove the whole oil pan? Or should I just be fine draining from the oil pan itself?

[philly98540]

Personally I would not do an engine flush for visible varnish unless there was another issue with the engine. The oil consumption due to stuck low tension rings or possibly an oil galley check valve malfunction, etc. issue, then I would consider it as a possible remedy for those issues. Many threads that show it can help for those type of problems. For a healthy running engine, the brown color on the internal parts does no real harm. All the machined surfaces where the oil does its work (where you cant see) are more than likely just fine and shiny clean. I wonder if introducing the flush on a healthy running engine could cause more issues than it solves as it could make some deposits come off in bigger pieces. I personally would use a high detergent dino oil with shorter change intervals to slowly remove varnish on a healthy running engine.

[R Shaffner]

+1
Rotella 15W-40 was the original spec oil for the M62. I've also used it occasionally in my M62TU for this reason.

[paul p]

Ahem..
https://www.bimmerforums.com/forum/s...p-rattle/page1

[Jason5driver]

Oh man, I do have quite a bit of varnish inside. Looks almost like rust. I might just use the engine flush for the little bits of sludge I saw and then drain it out when the car is warm to let it flow (bless my hands from being burned). If I do it, should I remove the whole oil pan? Or should I just be fine draining from the oil pan itself?

Most flush stuffs require you to pour contents into crankcase , let idle for 10-15 minutes , then drain .
I have to run a long 4" pvc pipe to exhaust out of the garage , because the engine will be burning the gunked crud out the exhaust when idling for 10-15 minutes .

[GZilla]

Personally I would not do an engine flush for visible varnish unless there was another issue with the engine. The oil consumption due to stuck low tension rings or possibly an oil galley check valve malfunction, etc. issue, then I would consider it as a possible remedy for those issues. Many threads that show it can help for those type of problems. For a healthy running engine, the brown color on the internal parts does no real harm. All the machined surfaces where the oil does its work (where you cant see) are more than likely just fine and shiny clean. I wonder if introducing the flush on a healthy running engine could cause more issues than it solves as it could make some deposits come off in bigger pieces. I personally would use a high detergent dino oil with shorter change intervals to slowly remove varnish on a healthy running engine.

That is exactly what my dad told me as well. He said the varnish on the surface has no effect on performance and it's a normal thing for aging engines. Some other E38 owners showed me their exposed engines and with the oil pan removed and mine looks relatively clean. I just watched M539restoration's most recent video and he used the same engine flush and it seems like it didn't really help him with his varnish and his sludge. My engine runs fine and is relatively healthy. I might just not do it.