New Monarks are in but.....problem - PeachParts Mercedes-Benz Forum

4thesporty · #1 10-31-2010, 10:26 PM

I replaced my original injectors tonight with a set of Monarks.

The car is more loud now, almost like it "could" be nailing. I have not heard that before, but it is more metallic sounding, if that makes sense. I thought it would quiet down a bit with these injectors.

Also, it seems that I have a leak from my prechamber. See this video:

http://www.youtube.com/watch?v=OWk4vxc5coo

From what I've read, this could be the return lines leaking. (I did re-use them) or the injector not tightened all the way.

What do ya'll think?

dude99 · #2 10-31-2010, 10:29 PM

bubbling around the base of the injector, did you reuse your heat shields?

4thesporty · #3 10-31-2010, 11:07 PM

Brand new heat shields, they came with the injectors.

I also researched and made sure I put them in the correct way.

79Mercy · #4 10-31-2010, 11:09 PM

New injectors are going to be louder for the first 200 miles or so. The FSM covers that. Nothing to worry about there.

However the leaking pre-chamber is a problem. I wonder if when you took the injector out it loosened the prechamber nut a little bit?

C Sean Watts · #5 10-31-2010, 11:20 PM

What did you torque them to?

Also, when removing the old ones did you put even pressure on the ratchet/bar or 'snap' it?

Diesel911 · #6 10-31-2010, 11:24 PM

Where the Injectors completely rebuilt are was this a Diesel Giant type Nozzle Swap?

You may or may not have a leak around the Heat Shield of the Prechamer. When fluid seeps past the Injector to Prechamber Ring/Collar threads it gets into space in there.

The heat and the shock wave created by the Fuel Burning (before the Engines warmed up and it is running put your Finger on and around the area of the Injector and see what you can feel) causes the liquid bubble out as if there is a leak.

It also could be a good time to re-time your Fuel Injection Pump.

DieselPaul · #7 10-31-2010, 11:28 PM

Did you pop test the injectors and check the spray pattern? I put new monarks from DG into an old body and it was horrible. After going through a couple spare injectors I got one to crack at 135 bar and spray perfect.

4thesporty · #8 10-31-2010, 11:32 PM

Quote:

Originally Posted by C Sean Watts

What did you torque them to?

Also, when removing the old ones did you put even pressure on the ratchet/bar or 'snap' it?

When removing I put the ratchet on and hit it with a hammer to break them free, I knew not to put steady pressure on them.

I torqued them to 50 ft/lbs. (However, this was a torque wrench from HF)

Perhaps some new heat shields and a proper wrench is in order.

4thesporty · #9 10-31-2010, 11:33 PM

Quote:

Originally Posted by Diesel911

Where the Injectors completely rebuilt are was this a Diesel Giant type Nozzle Swap?

Complete injector, brand new.

Tpawlik · #10 11-01-2010, 07:28 AM

I had Sean Watts rebuild mine with Monarch nozzles. They were so loud I thought something was wrong with the engine. But, I also had some air leaks in the fuel system. Find your fuel/air leaks. The new injectors will quiet down and so will your engine.

79Mercy · #11 11-01-2010, 08:25 AM

Quote:

Originally Posted by 4thesporty

When removing I put the ratchet on and hit it with a hammer to break them free, I knew not to put steady pressure on them.

You must have loosened the prechamer when you "broke" them loose. You should have applied slow and steady pressure until they came loose.

vstech · #12 11-01-2010, 09:23 AM

Quote:

Originally Posted by 79Mercy

You must have loosened the prechamer when you "broke" them loose. You should have applied slow and steady pressure until they came loose.

no.
this is a bad practice. smacking the breaker bar is the best way to get them out.
if a PC gets loose this way it would have gotten loose and totally unscrewed itself with steady pressure.

4thesporty · #13 11-01-2010, 10:03 AM

OK, here is my plan of attack. Please correct me if need be

1. I'm going to order new heat shields and new return lines.
2. Remove my injectors, install new heat shields and torque with a borrowed torque wrench from work (snap-on, and calibrated) 50 ft/lbs correct?
3. Install new return lines
4. Check for bubbling around PC

Can I use something to clean around and in the PC while the injectors are out?

I did notice some carbon in there when I had the injectors out, but didn't clean it with anything other than a shop rag. Perhaps this is the source of my leak.

rscurtis · #14 11-01-2010, 10:08 AM

You could have an injector leaking between the body and the nozzle. A good practice is to hone the parts with 1000 grit paper on a surface plate.

That engine sounds fine to me.

vstech · #15 11-01-2010, 10:08 AM

I was going to respond no, until I read the carbon part... yeah, get a new set of each, and get in there well with a good dental pic until the seats and threads are all clean steel! I noticed that pb blaster does a good job of softening the carbon on the threads! also, if you didn't clean out the carbon, you could have an extra shield in there, I've pulled heads with 3 in it before! clean until you can see the bottom of the PC quite clean!