Carbon removal trick? - PeachParts Mercedes-Benz Forum

H-townbenzoboy · #1 12-26-2003, 10:45 PM

I was up at the dealership today, and we were discussing diesels, and how to get them to start easier in cold weather. One of the guys in the parts department had this done to his Mercedes-Benz once. He had the glow plugs taken out, the plugs and the sockets where the glow plugs go in the engine were cleaned off with a special little brush. Then, with the glow plugs out, he turned the ignition, and that got some of the carbon to come out. After that, it started up real good with the plugs back in. So I just want to know if anyone here has tried that out.
-Joe

coachgeo · #2 12-26-2003, 11:21 PM

Quote:

Originally posted by dieseldiehard
..
While we on this subject, a little word to the wise. It pays to just change GP's every couple of years, and use the technique you described (with a GP reamer tool or brush) to keep carbon from building up and possibly causing ...

I have heard of the pencil plug carboned in disaster..... NO FUN. Soooooo. question.... if you suspect this might be could be a problem beforreeee you start pulling Gplugs; like say you forsee working on a poorly maintained pencil plug diesel, how would one prepair in advance for this issue. Soak area in liquid wrench? Run the engine for a few weeks in advance with diesel purge? And orrrrr?

coachgeo · #3 12-26-2003, 11:48 PM

Quote:

Originally posted by dieseldiehard
Hi coachgeo,
I suggest everyone interested do a search, use three words, Glow Plugs Reamer, and you will have nearly a hundred posts with every sage wisdom the Autoforum has to offer. The search box is great for this kind of thing..... there was a post that said that carbon does not dissolve in anything commonly usaed for loosening bolts and the like!
YMMV.
Dieseldiehard

Thanks, I agree about doing searches. Using the right key words to search by is the biggy that makes it all work out. Thanks for your hint. Also thanks for the heads up on the "screw loose" type stuff having any affect on carbon.

whunter · #4 12-27-2003, 01:27 AM

Hello Everyone
I am only posting this as an FYI and take no responsability for anyone foolish enough to try this.

Here is a primitive and Dangerous carbon removal trick.
Garden hose light/medium water spray directly into intake while engine is running.
I have seen this done on diesel and gas engines as a last ditch measure; to save it from the scrap yard.
The danger is that water is not compressible; get enough in any single cylinder and blow the rod, piston or head.
Basically; do not do this at all.

Before anyone asks:
I learned this trick from an elderly (85) retired trucker in1969, the fellow owned three MB diesels and eleven diesel semi tractors, average 500,000. miles between rebuilds.

I am only posting this as an FYI and take no responsability for anyone foolish enough to try this.

Begin edit.

Hello leathermang
I do not accept or encourage anyone to attempt the water injection process.
My most profound apologies if it appeared so.
I hold the personal opinion that it is a serious danger to even attempt this shady operation.
I can not agree that it should not have been posted at all; the freedom of speech is precious, and I wanted the negative aspects of this foolish procedure on record, before some poorly informed mechanic/technician finds out the hard way.

Sad to say, I was fired from an independent shop in the late 1970's for refusing to use this method, so my personal convictions have cost me at least one job.

Thank you; I did edit my earlier post, if you would read it and send me an e-mail with alternative wording I will be glad to edit again.

When I state that it does work; what I meant was that the last three diesels (CUMMINS with bent rods) that I knew had this process used on them where clean/no carbon, at a cost of a total overhaul + new rods and pistons.
The only proper way to remove carbon is at least a full head service, and some times a complete overhaul.

Again I apologize that I was not fully clear in my statement.

Have a great day.

coachgeo · #5 12-27-2003, 01:33 AM

Quote:

Originally posted by whunter
Hello Everyone
I am only posting this as an FYI and take no responsability for anyone foolish enough to try this.....

maybe a squirt bottle would work better? Use it to mist some water at the intake? This is basically all the water inject systems due. Hmmmmmmm with that in mind.... might even be better to mist rubbing alchohol instead. I have heard this has the same effect as water and maybe it is safer for the engine.

jseries · #6 12-27-2003, 03:16 AM

Quote:

Originally posted by whunter
Hello Everyone
I am only posting this as an FYI and take no responsability for anyone foolish enough to try this.

Here is a primitive and “Dangerous” carbon removal trick that works.
Garden hose light/medium water spray directly into intake while engine is running.

I wouldn't use a garden hose(that's a lot of water) and not too sure on dsls either but using a spray bottle or just tablespooning water into a carb works "well" on a gasso motor. One hand is going to be running the throttle linkage and the other spooning or spraying and there is NO WAY you're going to hydrolock a motor doing this. I've done this many many times but again only on gas motors and never a dsl so YMMV.

thebern · #7 12-27-2003, 07:19 AM

The last time (about 2 years ago) I replaced the plugs in mine the #3 plug would NOT come out. Fortunately it still worked. Well about two weeks ago it went dead. The previous tank full of fuel I put in an entire bottle of Redline 85 Plus Diesel fuel enhancer and drove it just a little harder than usual. The plug came right out! The plug appeared just a little damp as though the carbon had been softened by the Redline.

thebern

BoostnBenz · #8 12-27-2003, 09:47 PM

I took my injectors out to clean them and the only thing I noticed dirty was where the carbon was built up on the ends. I just got a compression tester which goes into the glow plug holes so I plan on running it very hard before pulling the GPs out to do the test, I'm hoping I'll get all of that carbon cleared out and the motor running a bit better as well as getting it ready for the GP removal. Nothing an italian tune up can't fix.

R Leo · #9 12-28-2003, 06:09 AM

Water fogging is an accepted method of decarbonizing marine turbines but I do not think I'd attempt it on one of these engines.

There are waaaaay too many bends in the intake tract (particularly, the turbocharged units) to ensure that the fog/mist was making it in there without turning into large (and non-compressible) water droplets.

leathermang · #10 12-28-2003, 12:01 PM

I think when done correctly this works on gas engines ..... I do not think this should be done to our engines due to the design ... ie, we have precombustion chambers...
Usually it is used to blow carbon from behind the exhaust valve .... and done wrong might bend a rod ( either of two ways... hydrolocking or excessive steam )...

In Viet Nam using UH-1H ( Huey slicks ) we had 1300 hp GE turbine engines... and we took a water hose to them ( while running ) once in a while... but we had a GE Tech Rep living with us and he usually supervised it....

whunter · #11 12-28-2003, 12:46 PM

Hello Everyone
That is why the title is "primitive and Dangerous carbon removal trick that works"...................
Also the reason for the legal disclaimer:
I am only posting this as an FYI and take no responsibility for anyone foolish enough to try this.

If we do not talk about the shady procedures that can be a danger to the vehicle and/or mechanic/technician; then some poorly informed person may well attempt it without consulting us first.

I watched a technician walk into a battery room, where there where batteries visibly boiling and very heavy hydrogen sulfide odor, standing over the battery charge rack I watched him light a cigarette, I confronted the manager who needed a full explanation of why it could be dangerous.

Have a great day.

leathermang · #12 12-28-2003, 01:39 PM

This is one time I don't think something should have been posted AT ALL....

Putting Dangerous into parenthesis made it look like you were saying ' WINK WINK' to the Dangerous as an adjective.. and for our engines/ or wrongly administered it IS DANGEROUS ....

Why don't we go back and just take this stuff OFF ?

So no one will think they know enough that they can do this... or that it might have some proper use for our engines...

I also really object to the " THAT WORKS" part of your statement.... I do NOT think it works ..... and this is what makes your post potentially VERY harmful....

whunter · #13 12-28-2003, 07:27 PM

Hello leathermang
I do not accept or encourage anyone to attempt the water injection process.
My most profound apologies if it appeared so.
I hold the personal opinion that it is a serious danger to even attempt this shady operation.
I can not agree that it should not have been posted at all; the freedom of speech is precious, and I wanted the negative aspects of this foolish procedure on record, before some poorly informed mechanic/technician finds out the hard way.

Sad to say, I was fired from an independent shop in the late 1970's for refusing to use this method, so my personal convictions have cost me at least one job.

Thank you; I did edit my earlier post, if you would read it and send me an e-mail with alternative wording I will be glad to edit again.

When I state that it does work; what I meant was that the last three diesels (CUMMINS with bent rods) that I knew had this process used on them where clean/no carbon, at a cost of a total overhaul + new rods and pistons.
The only proper way to remove carbon is at least a full head service, and some times a complete overhaul.

Again I apologize that I was not fully clear in my statement.

leathermang · #14 12-28-2003, 08:37 PM

I am glad we always agreed on the substance of the issue...
and I believe you have changed the wording to take out the possibile implication to inexperienced DIY's that you did not mean the word 'dangerous' in its usual context.
Perhaps that man's diesels were direct injection ? (non precombustion chamber for those wondering ).
Why did they have bent rods ? Or are you saying sometimes they bent them doing this procedure ?

whunter · #15 12-28-2003, 09:08 PM

Hello leathermang
Yes; the three diesels with bent rods were direct injection.
Why did they have bent rods; because a foolish person was doing this procedure, he was caught doing the third one and fired by the fleet owner.
I could almost thank the foolish young man; we pulled the heads on twenty eight other engines he had touched, found and fixed many other nagging problems, the boost in business did not hurt either.
Some of you may remember the late 1970's economy; it is possible the incident saved that service garage from going under.