Tips on cleaning around injector threads? - PeachParts Mercedes-Benz Forum

CarpeDiem51392 · #1 05-19-2014, 10:54 PM

Above where my injectors screw into the cylinder head (down by the heat shield/crush washer) is totally full of dirt etc. Any tips on cleaning this out? I'd like to remove the injectors and maybe clean them myself (following Jeremy's excellent guide) or pay someone to do this. But obviously I don't want all that crap falling in my prechambers. Should I just use degreaser and blast it out with water? I'm always weary of getting too much water around.
Thanks

vstech · #2 05-19-2014, 11:58 PM

I use engine degreaser, and a pressure washer...

charmalu · #3 05-20-2014, 12:14 AM

Take it to a DIY car wash and blast it clean with hot soapy water. Then rinse. The heat from the engine will dry it on the way back home.

Charlie

ah-kay · #4 05-20-2014, 02:33 AM

This is what I normally do. Run the engine warm, not hot. Spray it with 'Simple Green' degreaser or similar, wait for 1-2 minutes, brush dirt off with an old tooth brush and spray it with a water from a wahser bottle. Blast it with compress air. Repeat if necessary. Costs you next to nothing.

cooljjay · #5 05-20-2014, 04:06 AM

Just use a can of brake cleaner, will take it all off in a hurry. What I always use if I have a diesel leak and need to make sure I fixed it...

CarpeDiem51392 · #6 05-20-2014, 08:04 AM

Guess I was being too cautious, thanks all.

funola · #7 05-20-2014, 08:25 AM

"(down by the heat shield/crush washer)"

Do not blast it with water or anything water based if you want to clean out the heat shield seat area of the cylinder head. Use a long flat blade screwdriver wrapped with cotton jeans cloth strip, soaked with WD40 and twist it back and forth to pick up the carbon gunk little by little. Change jeans strip when there's gunk on it. When it looks clean, crank the starter to blow out any debris that has fallen into the pre chamber.

vstech · #8 05-20-2014, 11:35 AM

Quote:

Originally Posted by funola

"(down by the heat shield/crush washer)"

Do not blast it with water or anything water based if you want to clean out the heat shield seat area of the cylinder head. Use a long flat blade screwdriver wrapped with cotton jeans cloth strip, soaked with WD40 and twist it back and forth to pick up the carbon gunk little by little. Change jeans strip when there's gunk on it. When it looks clean, crank the starter to blow out any debris that has fallen into the pre chamber.

I totally agree with this advice after the injectors are out...

his question is concerning BEFORE he takes out the injectors...

funola · #9 05-20-2014, 12:17 PM

Quote:

Originally Posted by vstech

I totally agree with this advice after the injectors are out...

his question is concerning BEFORE he takes out the injectors...

I quoted his exact words: "(down by the heat shield/crush washer)". That to me is after he takes out the injectors. Just wanted to avoid misunderstanding and disaster.

Diesel911 · #10 05-20-2014, 08:05 PM

Quote:

Originally Posted by funola

I quoted his exact words: "(down by the heat shield/crush washer)". That to me is after he takes out the injectors. Just wanted to avoid misunderstanding and disaster.

I am guessing it is not a 616,617 Engine and He has a later Engine with the Splined Prechamber retaining Collar. On those the Injector is is threaded down near the tip and the Injector sits in sort of a recess.

On them while you cannot see the Heat Shield the Heat Shield is closer to the end of the Injector.

CarpeDiem51392 · #11 05-20-2014, 11:38 AM

Thanks funola, that's exactly where I want to clean out. I thought of using a screwdriver/rag like you said but I doubt I could get it all, it's so tight. Maybe I could blow compressed air on it as well with wd40.

funola · #12 05-20-2014, 12:28 PM

Quote:

Originally Posted by CarpeDiem51392

Thanks funola, that's exactly where I want to clean out. I thought of using a screwdriver/rag like you said but I doubt I could get it all, it's so tight. Maybe I could blow compressed air on it as well with wd40.

Not tight at all, a flat bladed #2 long screwdriver wrapped with a strip of denim works great. Just make sure you use denim and not a tee shirt. The tough denim is required so the screwdriver don't puncture through and scratch the head sealing surface. The woven denim is tough and acts like an abrasive cloth, together with the WD-40, rub the carbon away. The flat bladed screwdriver is needed to grab the denim so it does not spin against the screwdriver. A Philips head screwdriver would not work for example.

If the carbon is really thick, scrape most of it away first with a brass pick or whatever you can find that is softer than steel (aluminum strip?) so as not to scratch the cyl head, then spin starter to blow out the debris, then use the denim/screwdriver.

CarpeDiem51392 · #13 05-20-2014, 04:46 PM

I did mean clean while the injectors are in place. Dirt has collected in the recesses where the injectors screw into the cylinder head. Sorry for the confusion.

CarpeDiem51392 · #14 05-21-2014, 08:13 PM

1987 300D om603

Thanks for the insights. I think I'll just use degreaser, spray it off with a hose and let it dry in the sun. Doesn't sound like other people have had an issue doing this. It's mostly built up dirt, the car sat in a field for a while. Maybe I'll drag the air compressor out of the basement if I'm feeling ambitious.

CarpeDiem51392 · #15 05-22-2014, 09:56 PM

Thanks funola and diesel911 the advice on cleaning out the injector holes will come in handy. Sorry for the clumsy description. Part of the problem was I thought the "crush washer" sat above the threads of the injector and was visible. Looking at diesel911's diagram "retaining ring" is this part I see now.

duh.

Am I likely to find much carbon below the injector? To be fair, I think the last person who put a wrench on it was a German.