Yesterday I replaced all of my injectors. I have 278,800 mi. on the 82 300SD. I have been wanting to do this for awhile to see if I got better fuel economy. My old injectors were not nailing and were doing fine. Smooth idle.

Replaced all five with one that were rebuilt by a knowledgable person some here may have done business with. Torqued to 60 ft pounds and used new heat sheilds that he supplied with the rebuilt injectors (sheild-crush washer had smaller diameter hole than original MB seal to keep more heat off the injector nozzle). Cleaned openings where injectors insert and inspected visually. Are these the pre-chambers?

One of his injectors started nailing right off the bat. Pulled it and put one of my old ones back in that cylinder till he could send another one. No more nailing. Very noticeable increase in throttle response and power. Did have some idle shake that I did not have before this. My engine shocks and mounts are new. Could the rebuilt injectors with better spray pattern be showing up a pre-chamber crack that was not noticable issue before?

Drove 12 miles home on the interstate. Car was running 95-98 degrees. Last summer I had fan clutch replaced as well as thermostat and coolant flush with MB coolant at dealer - no problems since then till today. Popped hood when got in driveway at home and coolant was boiling in expansion tank. No such problems with old injectors.

Drove again yesterday. Had to turn on heater. Immediately a temp drop occurred when heat was turned on inside the car to the proper 87 degrees.

I guess I could repull all injectors and put my old ones back in and run it to see if the new ones are the problem. Is this coincidence or a problem with the rebuilt injectors or a pre-chamber issue? I do not have a pre-chamber tool to remove them.

__________________
1982 300SD Light Blue
2002 Honda Accord SE
1974 Toro Wheel Horse Tractor
2000 Toyota Tundra Pickup

While anything is possible, I tend to doubt that the replacement injectors are causing a prechamber crack to maifest itself. Each time you replace injectors, the spray pattern changes and the heat characteristics will vary. Adam recently had some issues with temperature with the new Bosio nozzles because they were not balanced properly. Slight differences between cylinders causes more waste heat for the cooling system to dispose of.

The injectors sit in the prechambers. When the injectors are removed, you should get a strong light and ensure that the prechamber ball is intact down in the bottom of the prechamber. At that mileage, there could be issues with loose or missing prechamber balls and this will definitely affect the waste heat generated from that cylinder. I had replaced the prechambers in the SD at 180K. Metric was fairly confident that they would not go another 100K.

Now, with regard to the 98 degree temperature........this is nothing to be concened about.........unless it goes higher.

What troubles me is that you noticed boiling in the expansion tank. This must be resolved immediately. If you do not have the proper 50/50 mix of coolant, or if you do not have a good expansion tank cap, and have insufficient system pressure, the coolant can boil. This is a dangerous condition and you must remedy it now.

Finally, higher temperatures then demand a thorough cleaning of the radiator......outside the vehicle.......using condenser cleaner, a pressure washer, and/or compressed air. Frequently, the airflow is inadequate across the condenser and the radiator and the temperatures climb.

I've noticed the SD start to climb lately when the ambient reached 76°F. or so. This does not bode well for the approaching summer season.


P.S.: How'd that climate control work out for you? Sorry it was such a POS.

I was looing at other posts on pre-chamber issues and on that third injector when I installed and it started nailing I tried bleeding each injector by loosening the nut at the injector with engine running. The nailing stopped on that injector when I cracked the line.

Well, each time I cracked the line it gave a big hiss and sprayed fuel out around the nut. Air kept getting in there somehow or either the nozzle on that new injector was plugged up. I was very careful to keep debris away from the IP and covered it with a clean cloth after remvoing the lines. I blew the lines off with compressed air before reinstalling.

After looking at other posts I am beginning to wonder more and more about a cracked pre-chamber on that #3 cylinder.

__________________
1982 300SD Light Blue
2002 Honda Accord SE
1974 Toro Wheel Horse Tractor
2000 Toyota Tundra Pickup

Well, I think the AC compressor is about to fail. It is clanking badly, at least the clutch is at idle. It occassionally locks up when turned on, but you can cut it off and restart and it will work. The tag says it was replaced in 1992. Performance Products has a deal right now where if you buy a new AC Compressor for $300 they give you a free expansion valve and drier. Good deal I think.

I did not check the pre-chamber balls. We are getting ready to move 90 miles from here and so yesterday I dropped the car at the mechanic. He did the cooling system work last summer. Maybe the aux fan is not working properly. I heard it running at idle and cycling on and off though.

I will get that climate control unit back sometime. I need to check one of my vacuum pods. The center vents still intermittantly switch on and off.

Is the pre-chamber ball part of the pre-chamber if you replace it or is it a seperate part?
PS - the fuel economy had dropped months ago to 24mpg per tank. I had been getting 27-28mpg. Could the pre-chamber balls effect fuel economy too?

__________________
1982 300SD Light Blue
2002 Honda Accord SE
1974 Toro Wheel Horse Tractor
2000 Toyota Tundra Pickup

I suppose it's possible that the compressor and/or clutch is putting a load on the engine, does it only overheat with the AC on?

I agree with Brian, if it's boiling while reading 98 C, I would start by replacing the cap. It shouldn't boil until well over 120 C.

That's an excellent deal for a compressor, dryer, and valve. You can pay that for the compressor alone.

The prechamber ball is part of the prechamber. You cannot replace it. It's on a shaft that's pressed into the side walls of the chamber. The shafts eventually loosen with time and the ball falls off.

The auxiliary fan is not the problem if you hear it cycling. It's rarely the culprit unless it won't start in traffic while the a/c is on.

I decided to permanently connect the center vents to vacuum. The pod is threfore energized all the time and I control airflow via the dash controls. It's a perfect modification and I thank Jim Ellington for the advice on this change.

My car always ran a solid 85-90 degrees on the hottest summer days and once I installed new Bosio nozzles, it shot up to around 100 (around 70 degree days when I did this). Once I had Tomj here balance the injectors I'm right back to my old operating temps. You may want to pull them out again and have the person who did them re-pop test them.

__________________
Adam Lumsden
(83) 300D
Vice-President of the MBCA International Stars Section

Well, Tom J did my injectors and did an excellent job. I wondered if the AC compressor was the problem and sitting in traffic or in a drive thru with the AC on or off the temp still creeps up pretty quickly. So that rules out the AC unless the clutch failure is causing an extra load whether the AC is on or off.

Tom said he was having lots of trouble with the Bosio nozzles so he fixed me up with some German Bosch nozzles. The power difference is huge. The engine response to my pedal is immediate where it used to be sluggish and delayed.

The first trip on the highway I put the pedal to the floor and kicked in the turbo and she flew and let off a big cloud of black smoke. It did not smoke after that. Must have just been some junk it blew out.

I was not letting the temp get up to 100. Temp has always run at about 85-90 degrees. Maybe I do not have a problem at all from what you guys are saying about the temp difference that new injectors can cause in operating temps. The expansion tank and cap are new. That day when I shut off the car it was almost full and I could hear and see it boiling in there but none was escaping from the cap.

__________________
1982 300SD Light Blue
2002 Honda Accord SE
1974 Toro Wheel Horse Tractor
2000 Toyota Tundra Pickup

In reading through the archieves, it seams that there's a lot of people with good things to say about them, drop-in bla bla bla...
And now there are a few people with balance and temp issues.

Since quality nozzles are so hard to come by which ones work well?

TIA

__________________
Stable Mates:
1987 300TD 310K mi (Hans)
2008 Jeep Grand Cherokee OM642 165k mi (Benzrokee)

If Tom did the nozzles, I doubt they are unbalanced by more than a few psi (Within specs or less). He has a very good reputation on the net and around the Denver/Boulder area.

Are you sure that it's boiling in the tank? Is it constant small bubbles or is it large, pulsing bubbles? It might be a blown headgasket. Check the tailpipe for wetness and check the oil to see if it looks like mud.

"Since quality nozzles are so hard to come by which ones work well?"
You can always goto the pick-n-pull yards and get your own nozzles. If you send them to Tom, he can clean, balance, and/or rebuild them for you. View THIS post for pictures of the different nozzles.

Well, the oil looks fine. I am going to change so will give a closer inspection. I am sure the problem is not the injectors. Tom knows what he is doing.

I doubt blown head gasket.

__________________
1982 300SD Light Blue
2002 Honda Accord SE
1974 Toro Wheel Horse Tractor
2000 Toyota Tundra Pickup

Thanks for the info, I have spoken with Tom regarding the OE Junk yard nozzles but the yard I'm currently dealing with them is too high on price, gotta make a deal first.

On the otherhand, Dieselgiant another acknowledged diesel guy seems to swear by Bosio's right out of the box, just curious whether or not balanced nozzles can be purchased and used out of the box, or does everything have to get find tuned by the likes of Tom and his great expertise

anyone have good luck with new ones out of the box?

__________________
Stable Mates:
1987 300TD 310K mi (Hans)
2008 Jeep Grand Cherokee OM642 165k mi (Benzrokee)

Installed Bosios "out of the box" on the 240D.

Nice results; no smoke, no nailing, nice idle, smooth running and return of lost zip.

i dont know the diff between turbo and non turbo injectors but i do know they are different.

does anyone know the diff and if the non turbo injectors are in there will it possibly overheat?

if it didnt run that hot before it would seem to indicate some defeciency to me.

tom w

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

I believe the only difference is the pop pressure. While NA injectors *will* work on a turbo engine, under boost it won't run right. At 10psi boost, the compression ratio is about 36:1 at sea level.