95 E300D, Asking for suggestions on cleaning carbon & oil paste around intake valves

[Texasgeezer]

Hopefully I'll be able to change my injectors once the weather warms up again.

Looking for suggestions on how to clean the thick buildup of gunk in the intake portion of the head. About 60,000 miles ago I scrapped a lot of it out, but was afraid to get too close to the thin valve stems. There is quite a bit gunk remaining.

I know a lot of the BMW diesel guys use a crushed walnut shell mixture method but don't want to do anything so drastic.

I'm thinking while I have the injectors out, there would be no danger of damaging the head, valves, or pistons if I used some type of solvent, brush, air nozzle combo. After cleaning spin the engine a few times to avoid hydro locking damage.

Any thoughts on this procedure. Solvent to use, etc....

Possibly will be changing the glow plugs at the same time. Thought the solvent might help make extraction a bit easier.

[Sugar Bear]

IMO it would be difficult to damage a valve stem using any hand tool except a hammer. I'd use a scraper made from hardwood that you could shape as needed. Make sure both valves are completely closed, scrape away and blow it out with compressed air.

Look into adding a catch can to the breather system to reduce intake buildup.

Good luck!!!

[Texasgeezer]

Thanks for the suggestion.

What I plan to do, unless someone suggests a safer way is to pull all the injectors for swap out with a set rebuilt by greazzer. Leave them out while cleaning the intake valve area including using a spray solvent. Possibly use a combination of nylon flexible brushes and strips of sponge or 3M abrasive pads. Also have a vaccuum running to suck as much of the liquid and gunk out before it falls into the cylinder.

I'll probably use diesel as the solvent unless someone suggests a better liquid.

I'm hoping that any excess liquid will be pushed out of the opening where the injector and sealing ring were installed. I'll have a helper spin the engine to pump the excess out of the exhaust valves and open holes where the injectors were removed.

This is the main area where I'm looking for suggestions. I'm concerned with a vacuum exploding if the diesel fumes are ignited by the vacuum motor. I don't plan to use much diesel, just enough to clean the surface really well and wet the sponge, rag, 3m pad.

I did add a bypass to the breather system about 60,000 miles ago but wasn't able to get all the gunk out at that time by scraping with a bent small spoon.

[Sugar Bear]

I don’t know about diesel fuel getting into the vacuum causing an explosion. Your caution is wise and merited.

For scrubbing consider toothbrush size brass and stainless brushes.

Good luck!!!

[87tdwagen]

A few good solvents you could try:
Acetone, will cut thru carbon and gunk quickly, also evaporates very quickly minimizing vapor related concerns. Downside, is the fumes while using it, so use sparingly in well ventilated area, or if working for extended periods of time use a good VOC rated respirator like a painters unit.
Seafoam works well albeit slower. Can also be had as an aerosol labeled Deep Creep
WD-40, sucks as a lubricant but great at cutting thru gunk, weakest of the options listed but it works and is the safest across the board.

Good luck

[ds190]

I used diesel when I cleaned out the crud in the intake manifold.

I would use a nylon bristle bottle brush and diesel fuel to get in the intake side of the head to clean the crud out.

Then soak up the liquid with a rag and turn the engine over just a few times.