Going to clean the injectors - PeachParts Mercedes-Benz Forum

TTCummins · #1 11-19-2007, 12:45 PM

I have finally had enough of the horrenous idle when cold in my car. Now that the glow plugs have been sorted out it still does it, next on the list is injectors. Only paying 700 bucks for the car, buying new ones is not an option. I am going to take them out and clean them. We have a really awesome ultrasonic cleaner at work that i can use to clean parts as well as a polisher if something needs a quick buff. My question is what is going to work best to clean the junk out of the nozzles when i get them apart? Isopropyl Alcohol, gunk engine degreaser, penetrating oil of some form? I searched for some torque specs but the only ones I found were for a 617, having a different head than the 603 I was wondering what the injector torques are?

Looking for all three
Assembly torque for the two halves of the injector?
Installation torque into the head?
Injection line torque?

Thanks

Kurt Kiefer

Stevo · #2 11-19-2007, 01:04 PM

I use "Hoppies" gun cleaning solvent.

Phinfan39 · #3 11-19-2007, 01:07 PM

Have you tried running Diesel Purge through them? I'm not sure if this would help you but it seems easier to do then completely removing all injectors and rebuilding them if the only problem you have is dirty injectors.
Maybe someone with more experience can shed some light on whether this will work or not. But if it will it's easy to do.

BIGRED · #4 11-19-2007, 01:13 PM

NEVER use solvwent in an ultrasonic cleaner ...It can BLOW UP in your face.

And order replacement heat shields. They crush into place when your torque the injectors into the head

Torque is 70-80 NM for halves and injector to head

Stevo · #5 11-19-2007, 01:46 PM

Quote:

Originally Posted by BIGRED

NEVER use solvwent in an ultrasonic cleaner ...It can BLOW UP in your face.

And order replacement heat shields. They crush into place when your torque the injectors into the head

Torque is 70-80 NM for halves and injector to head

I should have said I "soak" them, not using a ultrasonic cleaner.

Kestas · #6 11-19-2007, 02:35 PM

I clean parts ultrasonically in solvent every day. It's never blown up in my face. It's rather alarmist to say to NEVER use solvent. The caveat is to not let the ultrasonic run too long, or the solvent will overheat and may cause a fire. Anything under 30 minutes is safe. Anything longer than that either needs to either be attended to, or the bath needs to run on a timer.

Many injector cleaning houses use xylene as solvent.

TTCummins · #7 11-19-2007, 03:17 PM

We use alcohol in our lab everyday, methanol at times as a cleaning solution. It does not blow up and will not blow up if used as instructed to in the manuals. We have never had a fire or any thermal incidents as they are called in the history of the company. It can be done. Removing the injectors will give me a chance to see if they have ever been replaced and the condition of them more accurately I believe. If they have 200,000 miles on I'll find out. I have two other vehicles to drive and an open bay to work in so I am not missing anything by tearing this apart. Plus I stand to gain mpg and a smoother idle. In this case I think I will just spend the time to do it.

TTCummins · #8 11-19-2007, 03:18 PM

I suppose I should mention that the Basin of the sonic cleaner is filled with water and the parts are immersed in beakers with cleaning solution. Yeah, not the whole basin with alcohol, that would probably burn some stuff down.

BIGRED · #9 11-19-2007, 05:01 PM

I am obviously wrong... if you understand the cause and effect and what you can and can not do.... go for it. I don't have a clue and read about someone else that had it flash and burn them.

toomany MBZ · #10 11-19-2007, 06:41 PM

Paying $700 for a car, an MB diesel to boot, and not sinking any more money into it to get it running?
Good luck.
When I took apart my injectors, I sprayed 'em with brake cleaner. You may need to replace the nozzles.
Heed Phinfan39's advice.

darkman · #11 11-19-2007, 10:24 PM

I don't know the history of your car but one thing
I learned from this forum is that these diesels have
to be allowed to run ("drive it like you stole it").

I'd try the diesel purge.

I also find that sometimes I can just use some white
Power Service and run it a half a tank one way... the
other half back (on a trip)... and afterwards it idles
like a sewing machine.

Try Ypsi to Chicago and back. The Indiana speed limit is 70.
That'll give you some "room" to open it up some. Have some
fun while you're here.

TTCummins · #12 11-20-2007, 07:26 AM

I have been on several long trips in the car, and usually i do use the power service in every tank. It does idle pretty well after i drive the car for an extended period on the freeway. But when I start it up in the morning, one of the cylinders misses so bad the engine almost momentarily stops. The glow plugs are good and the compression is balanced across the board. Yes I am prepared to put nozzles in it if thats what it takes, but I would like to try disassembling them and cleaning them first before I drop another 300 bucks on parts. I already had to put an ignition, rear brakes, tires, and some other misc electrical parts in it so its up to about an 1100 dollar car now.

But it is definitly starting to come together

TTCummins · #13 11-20-2007, 07:41 AM

Test cleaned some junk nozzles last night and the results are in, drum roll please.......

Best cleaner by far and away is the general purpose degreaser we have in the lab. It is a concentrated syrup that I mixed at 1-1 with water. Parts came out looking almost new just a little discoloration around the actual fuel opening.

Next was solvent it loosened up the carbon and it only took a brass brush to take what remained off.

Alcohol and Methanol both did a great job at pulling the oils out of the nozzle but did little to remove the carbon build up.

All were run in the same ultrasonic cleaner at a solution temp of 45 degrees C for 90 minutes.

Kestas · #14 11-20-2007, 09:27 AM

I had an experience that was similar to TTCummins. My colleague bought 8 injectors for a V8 engine from a salvage yard. He installed them in his project car and none of the injectors worked. We believe thay sat for some 10 years in the yard.

I set him up with an ultrasonic bath, a variable voltage souce (not 12v, which would fry the injectors), ethanol solvent, and clear tygon tubing to fit over the injector nozzle. The procedure included immersing each injector in the ultrasonic bath, filling the tube with solvent, applying just enough voltage to open the injector, then blowing into the tube to reverse-flush the injector.

There was a good feeling of satisfaction watching the crud flow out of each injector. We brought all 8 injectors back to life this way, and my colleague now has a smooth running engine.

But take heed to TTCummins' note on the carbon crud that is present on diesel injectors. I think I know what kind of cleaner he used, but I don't have the name of it with me.

Cervan · #15 11-20-2007, 09:48 AM

i suggest the strongest cleaner you can get your hands on, if it eats paint its good enough for injectors. also, you have a buffing wheel take out the pintle and buff the end of it and make it shiny and smooth. then soak the rest of the injector in a solution or whatever.