Monark nozzles - PeachParts Mercedes-Benz Forum

Jtn190d · #1 10-08-2009, 09:42 AM

Hi all i have 87 190d 2.5 turbo engine, im looking to get my injectors rebuilt, are monark nozzles any good? how much do they cost and what model will fit my car? also dos any one know of a good place to get them rebuilt. Thanks A Lot

charmalu · #2 10-09-2009, 09:39 AM

There are some members that rebuild them here on the forum.
BGKAST does good work, Do a search on his name and PM him. I can`t help you on what fits your car.

Also DIESEL911 is quite knowledgable.

Charlie

sasquatchgeoff · #3 10-09-2009, 12:27 PM

I have Monarks on my 602.911 and love them. Quieter, smoother, and more efficient than the Indian-made Bosch nozzles that the injector shop installed originally when they rebuilt my injectors.
You might want to give us a location in order to better recommend a shop. Otherwise, check out the Bosch website and peruse the authorized dealers.

300dOwner · #4 10-09-2009, 12:39 PM

I installed Monarks on my '85 300D am am very happy with them. I bought the nozzels and rebuilt them myself (search the forum for pop testers) after buying a set of old injectors to use as cores (and I wanted to have an extra set ready to go)

Frankly, the cost of putting together the pop tester, the shims and nozzles...I'd recommend BGKAST...all I've read says he does a great job

Performance wise, they're running great.

Dionysius · #5 10-09-2009, 07:17 PM

Yes the feedback on Monark is excellent. I X2 it.

The Bosch nozzle has a tiny hole with feeders within the pintle. One has to use a magnifying glass to see it. It is there for better slow engine performance. In almost every car out there they are plugged up with carbon.

The Monark design is different and does not have this tiny hole to get plugged up. They are made in Germany to the highest specs with great QC.

One should have a balanced set to within 5 bar for smooth engine performance.

Injectors will work beyond all reasonable limits but they will be sub-optimal. They are a very ill-maintained part of the diesel picture. Eventually you will begin to hear the dreaded 'nailing' cacophony chiming in. Be kind to your engine and it will serve you very well.

Sev · #6 10-09-2009, 08:12 PM

where does everyone buy their monark nozzles and injector rebuild kits?

Diesel911 · #7 10-09-2009, 08:14 PM

Quote:

Originally Posted by Dionysius

Yes the feedback on Monark is excellent. I X2 it.

The Bosch nozzle has a tiny hole with feeders within the pintle. One has to use a magnifying glass to see it. It is there for better slow engine performance. In almost every car out there they are plugged up with carbon.

The Monark design is different and does not have this tiny hole to get plugged up. They are made in Germany to the highest specs with great QC.

One should have a balanced set to within 5 bar for smooth engine performance.

Injectors will work beyond all reasonable limits but they will be sub-optimal. They are a very ill-maintained part of the diesel picture. Eventually you will begin to hear the dreaded 'nailing' cacophony chiming in. Be kind to your engine and it will serve you very well.

I think the Ball Pin in the Pre-combustion Chamber is what allows worn out Injectors stay in use longer. Besides the fuel hitting it and aiding in atomization; ounce it is hot it must also vaporize the Fuel.

Below are some pics of what you described.

sasquatchgeoff · #8 10-09-2009, 08:23 PM

Quote:

Originally Posted by Sev

where does everyone buy their monark nozzles and injector rebuild kits?

mercedes source is where I got mine...

Dionysius · #9 10-09-2009, 08:26 PM

Thank you for those pics Diesel911.

I once removed nine....yes 9.....injectors from a 240D and a 300D. Both engines were running well and getting good gas mileage. I expected to find the Injectors would check out good on my Tester.

Guess what!!!! All nine had poor spray patterns and only two had pop pressures anywhere close to the mark. I WAS ABSOLUTELY APPALLED. That one piece of experience taught me more than any book could ever teach me.

Diesel911 · #10 10-09-2009, 09:20 PM

Quote:

Originally Posted by Dionysius

Thank you for those pics Diesel911.

I once removed nine....yes 9.....injectors from a 240D and a 300D. Both engines were running well and getting good gas mileage. I expected to find the Injectors would check out good on my Tester.

Guess what!!!! All nine had poor spray patterns and only two had pop pressures anywhere close to the mark. I WAS ABSOLUTELY APPALLED. That one piece of experience taught me more than any book could ever teach me.

Did your Engines run noticably better after you rebuilt the Injectors?

My car had 198k on it when I bought it. I think it had the origional Injectors. The part of the Spray Nozzle metal that Heat Shield did not cover was all eroded away. And, as you said the spray patterns were no good and also the drilled holes, both of them were plugged solid with Carbon.
Rebuilding the Injectors is what cured the bulk of my Idle shaking.

Dionysius · #11 10-09-2009, 10:08 PM

Quote:

Originally Posted by Diesel911

Did your Engines run noticably better after you rebuilt the Injectors?

My car had 198k on it when I bought it. I think it had the origional Injectors. The part of the Spray Nozzle metal that Heat Shield did not cover was all eroded away. And, as you said the spray patterns were no good and also the drilled holes, both of them were plugged solid with Carbon.
Rebuilding the Injectors is what cured the bulk of my Idle shaking.

It ran to what I consider top performance for this fine engine. Strangely enough this was not that far removed from what it was running under the old ones. I noticed a vibration at idle on one of them was corrected. They also sounded more robust and symmetrical in timing. I believe our ear can pick up very slight timing asynchronisms. What was amazing to me was how much tolerance there was to what I considered to be totally sub-par and unacceptable nozzles. The Monarks are king like their name implies. I will not return to Bosch Injectors.

One clue as to a worn Injector is if you run your finger on the pintle you will find it a little grabby into your fingerprint ridges.

What is very important about my finding, which should be a real heads up to all out there who care, is that they are a definite maintenance item. I never looked on them as that before. I advise everyone to have a Tester and check them and re-calibrate them every 80,000 miles at least. You will not be able to guess at their condition from any external signals. I also think it is imperative to do the balancing yourself. For the shop to do a fine job they will have to charge you too much. Buying a rebuilt set or even a new set will not guarantee 5 bar balancing. The specs allow a 10 bar spread even on new.

Another thing is that I would say it is not possible to properly clean the Bosch center hole and feeds. The risk of scratching and gouging is too great. I am surprised that the Bosch Designers have stayed with this design.

jt20 · #12 10-09-2009, 10:16 PM

The ball in the pc is there to mix the already-atomized fuel with the air for more efficient combustion

jt20 · #13 10-09-2009, 10:18 PM

Quote:

Originally Posted by Dionysius

The specs allow a 10 bar spread even on new.

they allow 5 bar as the entire range of the set.

sasquatchgeoff · #14 10-09-2009, 10:21 PM

Quote:

Originally Posted by Dionysius

I advise everyone to have a Tester and check them and re-calibrate them every 80,000 miles at least. You will not be able to guess at their condition from any external signals. I also think it is imperative to do the balancing yourself. For the shop to do a fine job they will have to charge you too much. Buying a rebuilt set or even a new set will not guarantee 5 bar balancing. The specs allow a 10 bar spread even on new.

I would add that once rebuilt, injectors should be tested and adjusted accordingly at about 6000-8000 miles. At least that was the case with mine. The new nozzles "settled in" and consequently got slightly out of calibration (since we're shooting for perfection here) - my father remarked that "a diesel either runs perfect or like sh*%," "there is no in-between" - these words have haunted me for some months now.

Also, my FSM calls out 5 bar not 10, and Rod at Diesel Fuel Injection Service in Portland knows I like them within 25 PSI of each other - and he can do it.

scottmcphee · #15 10-09-2009, 10:49 PM

If you're not having somebody else do your nozzle replacements, then get a shim kit too, of various thicknesses. You might need some to adjust the psi to get a balance. I set my Monarks a little above the top end of the spec, and advanced IP timing a bit.