E46 Fanatics Forum banner
1 - 8 of 8 Posts

·
Registered
E46 '04 330Ci convertible 780 K km
Joined
·
1,544 Posts
Discussion Starter · #1 · (Edited)
There is a description of a process to clean combustion chambers and piston compression rings.
That procedure supposed to be performed after engine cleaning described in part 1. Ultimate engine flush process, part 1.
There is a reason for that. Process requires to pour DMSO into cylinders. Certain amount of liquid (in some cases, lot of that) leaks trough compression rings and mixes with oil. If engine wasn't cleaned before, there is a change that some sludge could migrate to oil passages.
Please read carefully to the very end, to make sure you clearly understand process, before do actual work. There is nothing complicated, yet there are certain important moments to note and precautions to follow.

What you need:
1. DMSO 99% in a quality of at least 400 ml per cylinder
big syringe - 50 ml, 100 is better, if you can get one.
Teflon white hose 6 mm or thicker.
Container to collect used DMSO
New oil, oil filter.

Such procedure is optional, it removes carbon deposits off the pistons, frees compression rings, so obvious improvement in performance expected. Recommended for engine with uneven compression. If you have a borescope, remove spark plugs on cold engine (camera is temp sensitive) and inspect cylinders. If your piston looks like on photo, following procedure is for you.

918056



At the end of procedure, you will need to run engine. It will create very stinky smoke, so you have to consider ways to deal with angry neighbors and risk of separation/ divorce with your spouse. Your family will remember your funny smoke trick for years. I kid you not. It heavily smells like a garlic. Vampires free area. Once you feel that smell, you will never be the same understand. So, job has to be performed in open area. Not in underground parking. Not in garage.

First, cover everything in engine bay with plastic sheets/ rugs/towels. It is hard to avoid any spills/ splashes, and as now you gonna deal with undiluted liquid, it is very aggressive so you have to protect surfaces.

Gloves, goggles are compulsory! Any spills on your skin - wash it with water immediately!

Run engine to working temperature. The hotter it stays, the better.
Heat DMSO using water bath (safest way ) to at least 60C.
Remove coils and plugs. Use paper towels/ napkins to cover areas between valve cover ribs around plug wells. It will absorb any unavoidable spilling. Do not worry about valve cover- its plastic won't be damaged with DMSO but you do not want liquid to stay in any unreachable areas.


918055



Remove clutch fan to get access to crank bolt. Crank engine with wrench to set all pistons to mid level (use some sticks to see the level). It is impossible to make them all in one line but you try to get it as even as possible.
It is good if you could rise right side of the car as high as safely possible, in order to get pistons surface as close to horizontal as possible. It will help liquid to cover pistons evenly.
Now using syringe, fill every cylinder with hot DMSO very carefully. Try not to breath the vapors. Put 150-200 ml to every cylinder. (it is helpful to get Teflon hose attached to syringe. Rubber vacuum hose would work as well, as rubber can handle DMSO. Yet, teflon hose is more rigid so you could control it easier. That material stands high temperature and resistant to most of chemicals.
Now, Take 30 cm-long Teflon hose and cut 3-4 cm split at the end.
918050

fix another end to screwdriver and carefully insert spitted side into cylinder and run screwdriver with slow to moderate revs, using that hose as a mixer, moving liquid inside cylinder. It flushes walls, gently scratches pistons and helps to dissolve carbon. Run ti this way for few min in every cylinder. In my experience, 3-5 min in every cylinder, then repeat, and again. Try to do it as much as possible. Ideally, an hour would be good, but your back will ask you to stop far before that.
Now,using syringe, try to suck as much of liquid out of cylinders as possible. It will be very dirty, with some sandlike carbon crumbles. You need to wash them out of cylinders as clean as possible.
Now pour another batch of fresh heated DMSO. Use mixes to flush chambers. suck it out with syringe.
Now new portion - something like 100ml to each cylinder. Then use wrench to crank engine in order to move cylinders up and down, about 30 degrees. You need it to make piston rings to move, to free them completely.
Let liquid stay there for 20 min or so, moving cylinders every couple of minutes. Remove liquid. Do not ever leave wrench attached to crank!

Important: as it is winter now, your engine cools down. for DMSO to work, it has to be at least 60 C. Keep it in mind! Also, do not leave DMSO in cylinders (nor in a crankcase) overnight! You have to drain oil while engine is hot!.

Now, dirty part. Remove fuel pump fuse. cover spark plug wells wit some soft rug, then crank engine for few seconds, in order to get rid of any liquid left in cylinders. Check rug. it is dirty and wet. Repeat, unless you see not more liwuid gets off cylinders on the rug. It is critical not only in order to avoid hydro-lock, but also to leave as less dirt in engine as possible, to put low load on cats.
Connect plugs and coils, get fuse back. Start engine.
At that point, if chamber is clean and rings are free, it suppose to start easily.
there is a change engine loses compression at this point, as if it was very dirty, now carbon is gone but rings aren't free yet, there is lose of compression. So you might need to crank for longer. Do not give up.
When engine starts, you will see thick white smoke. It stinks with terrible garlic smell. I warned you. Deal with it now.
Depending on how effectively you were able to remove dirty DMSO from cylinders, your car will smell for couple of hundred km.
You just run engine for few minutes, then stop it and change oil and filter. you will need to run another oil change in couple of hundred km again, as some DMSO still is in system.
Obviously, such burning will get some load on your cats. If they are in good condition, they will handle it without any consequences.
Spark plugs. They will not look good, so you can replace them after no more obvious smoke out.

s
918051
 

Attachments

·
Registered
E46 '04 330Ci convertible 780 K km
Joined
·
1,544 Posts
Discussion Starter · #4 · (Edited)
Thanks, an after pic of the piston surface would be great!
-fana
It is hard to get a photo of chamber right after cleaning as engine is still hot, and borescope camera doesn't hold heat. And engine has to be run right after cleaning in order to burn/ push out any substance left. So pic is caught after 10 min run followed with oil change, next morning when engine is cold. center is still wet/soft. One more round of such cleaning will bring pistons to factory conditions.
918137
 

·
Registered
2001 330xi 5-spd pre-facelift
Joined
·
42 Posts
Thanks for the description in both parts! Did you notice any difference driving the car or is this mainly for oil consumption? I wonder if there are simple circulation pumps and heaters from chemistry equipment that could be rigged up to make this process easier? If it requires much investment, maybe a bunch of forum members could split the cost and pass the equipment around. I can’t imagine this needs to be done very often?
 

·
Registered
E46 '04 330Ci convertible 780 K km
Joined
·
1,544 Posts
Discussion Starter · #6 ·
Thanks for the description in both parts! Did you notice any difference driving the car or is this mainly for oil consumption? I wonder if there are simple circulation pumps and heaters from chemistry equipment that could be rigged up to make this process easier? If it requires much investment, maybe a bunch of forum members could split the cost and pass the equipment around. I can’t imagine this needs to be done very often?
There was obvious improve in performance. Clearly more response, some power definitely restored. I could explain it by freeing compression rings and restored compression. Unfortunately I didn't measure it right before procedure. (Anyway, compression test isn't conclusive unless there is obvious difference between cylinders. At some point, very dirty combustion chamber can have high compression because carbon could work as sealant around rings, and thick layer of carbon on upper part of cylinder and on a piston surface decreases chamber volume so compression stays high) Cleared chamber and free moving rings restore optimal conditions for ignition, so power increases.
I hope you notice a mileage of my engine though.
I do not say that any engine after procedure will get +20 Hp, +100 XP and two xtra lives. But it definitely would be noticeable in many cases. Again, the target is not to gain power, but to provide healthier conditions to old engine, to prolong its life.
For special equipment - I am sure there is a way to improve technology of a process to make it more effective and safe. Question is - how feasible it is. If you wanna perform such procedure on your engine, it is simple and effective as it is.
Do not forget that such procedure has to be performed on hot engine, so heating of liquid isn't enough. On Dubai summer I stop engine at 9pm and it is still above 40C at 7am. So I can run such procedure for 3 hours and it still be effective. If you do same with ambient temp about 0C, you barely have an hour before engine become too cool to keep DMSO active enough.
 

·
Registered
2001 330xi 5-spd pre-facelift
Joined
·
42 Posts
Wow, I didn’t see the 755,000 km! Thanks for the feedback. Yes, my main concern was to make the whole process faster (do all cylinders at the same time) and also maintain the 60C+ of the DMSO if it’s being circulated (And to prevent any back injury from leaning over that long!). This might even make it feasible in 10-20C environments. I’m only at 184k km, so I don’t think I need to do anything at the moment...
 

·
Registered
E46 '04 330Ci convertible 780 K km
Joined
·
1,544 Posts
Discussion Starter · #8 ·
Wow, I didn’t see the 755,000 km! Thanks for the feedback. Yes, my main concern was to make the whole process faster (do all cylinders at the same time) and also maintain the 60C+ of the DMSO if it’s being circulated (And to prevent any back injury from leaning over that long!). This might even make it feasible in 10-20C environments. I’m only at 184k km, so I don’t think I need to do anything at the moment...
Change oil often, maybe run BG EPR flush once or twice , and your engine should to be fine. Oil goes to cylinders either trough bad oil rings or trough dead valve stem seals ( or when oil separating valve is damaged, but it is rather rare).
For temperature, hotter it is better DMSO works. That is why hot engine is important. But cleaning can be performed successfully even if ambient temp is close to 0C. Just have everything ready. Again, cylinders cleaning isn't some procedure to run immediately.
 
1 - 8 of 8 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top