Thanks. Yes that is consistent with all your informative posts I have seen. I have an inquiry in with Bosio to see if they have an injector to match the 314.
Would it be worth doing a compression test before with the old injectors and putting the stronger pop tested rebuilt injectors where the compression is weakest? Maybe test the old injectors before putting Bosio nozzle in. If a few are off would indicate need of more extensive rebuild? Is this kind of matching of any use? Have not had a test in 100k so it would be interesting to see the difference.
I am nervous about putting a Bosch in this car. Reman engine from merc is like $20k.

Hi Meles,

I don't think there is any benefit to matching injector pop pressures with cylinder compression pressures. I wouldn't worry about that. It would be nice to pop-test the injectors you are using now, they may not be that bad. If they are well under spec, they should be cleaned and/or rebuilt, or replaced with good rebuilds. Matching the injectors to within 5 bar (or better) results in a smoother idle, and slightly smoother running in general, but that's about it.

You might be surprised by the lack of improvement with new injectors. I had mine cleaned & tested about 50kmi ago, and I pop tested them recently and they were mostly ok, not great, but not terribly bad either. But with fresh Bosch Germany rebuilds (matched within roughly 3 bar), there was almost no change in MPG or power. I did get a bit less soot out the tailpipe at a cold start, but that was it. If you are expecting a huge change in performance with new injectors, you may be in for disappointment.

Don't worry about injectors possibly causing damage to the engine, that would be extremely unlikely. Any decent name-brand injector, properly matched within at least 5 bar, should be fine. There are a couple of places selling NOS Bosch Germany #265 nozzles if you don't want the Brazil/India nozzles. Another option is to just buy the #314 nozzles, or whole injectors, from an MB dealership. The only place you'll find rebuilt injectors with #314 nozzles pre-installed will be the dealership. All other places will sell you an injector with #265 nozzles.

Thanks gsxr,
Since about ready to go out of town, I am not going to pull the trigger on anything until mid-July. Reman from dealer are $83 a piece and the parts guy says he shows a superceded part number so that jives with what you are saying. Returning my remanned ones to the online parts place. Waiting to hear from Bosio. If they don't have a special version I will be in a quandry. Would you do the standard Bosios over the 314? My injectors are in pretty good shape. They are being replaced because of weird miss when engine is very cold in the winter. I figure after 250k its just a good idea and may get rid of that problem. Matches with some research and cheaper than the $1000 I've been quoted for pulling the tank to go after diesel sludge (thinking that is a fishing expedition, but I have been pounding the fuel system with some wild additives; pri-ocide and pri-d). If the injectors are not right I will notice since I think mine are pretty good.

I think I would try to get the proper 314's. I think you can get the rebuilt 314's (p/n 003-017-29-21-88) for a bit cheaper, MSRP is $86, and MB F/L lists them at $67 each (with a $13/ea core charge). The note in the EPC says "the old part (i.e., #265 nozzles) must no longer be installed". That could be more for emissions reasons though, who knows.


Uh... a "weird miss" on a 3.5L engine automatically brings to mind the infamous bent rod syndrome. What's your oil consumption like? How many miles per quart? A tight 603 should be a quart per 6000 miles or better. If you're having to add a quart every 2000 miles or so, I may have bad news for you...

Thanks gsxr. Now I have to start worrying about this car again! That is an amazing number at 6000 miles or better for a quart. Friend of friend in NC had just gotten one over a year ago and was claiming neglible oil loss on one with about 200k. Mine has been going for the last 110,000 miles using a quart every 600 miles! Mechanics in Columbus claim this is typical (for this and 350sdl) and does not mean you need a new turbo which the stealer wanted to put in at $2800 (I had 2 unnecessary ones done, the 2nd being a claim by the mechanics in Dayton that the turbo was bad forcing the turbo rebuilder to provide another, out $1400 total.) Columbus guys also claim car good to around 300k on average. They definitely know what they are doing as they got the car flying by replacing some of the vacuum control parts unique to the w140 diesel. That was Lynn at MBClassic now MBStarPerformance (may no longer be with them I've heard.) They also maintained (contrary to myth and rumor) that what goes on these cars is the oil pump drive train after about 100k. (I've seen posts somewhere recently on 350sdl stating a washer goes bad there.) They have seen quite a few of the 350sdls have this exact problem and the engine was completely destroyed, as in not rebuildable.
If I can't shake this issue you may be right. Would this show in compression numbers? Mine were actually rather strong back at 175k.
If this is the case, when do you rebuild? Before or after destruction with ovaling? Was on the couch with Mike at Metrics Motors back many a year ago and he said not to rebuild at that time.

Meles,

There is a very long thread at this link with discussion about the 3.5L issue... buried in there is this link which has some interesting info from a pretty reliable source. For the record, I don't buy the "low cetane" excuse. And I have never heard of the alleged oil pump issue, that sounds like complete myth to me.

But anyway: Using a quart per 600 miles, you definitely have some damage present. But if it's been the same for the last 110kmi, wow... that's impressive. If it were my car, and otherwise it ran well (good power, MPG, no smoke) then I'd just keep driving it. When the power drops, MPG plummets, smoke increases, or oil consumption gets worse (100-200 miles per quart)... then I'd rebuild it. Make sure you're using good diesel oil (Delvac 15W-40, etc).

The compression numbers can show this problem after the bent rod (or ovaled cylinder wall) gets bad enough. If it doesn't yet show on a compression test, it may not be that bad. Remember that you're only looking for more than a 3 bar drop from the best cylinder, and cyl #1 and/or #6 seem to be the common failures. If you love the car and have the time/$$$, sure, rebuild it now. Otherwise, I'd wait until it gets worse. They can sleeve the block, install the new/updated rods, and new pistons if necessary. Metric should be able to do it for well under $10k.

gsxr,
Well I messed around with SVO the other weekend (stopped by Aldis and bought over 20 gallons worth and then periodically added on trip to Cleveland as the tank got low.) Pure canola coursing through the vehicle. What was cool is that when you have fuel leaks the canola just kind of comes out and stays there. It does not evaporate. You are left with glistening Canola. Very easy to see where current leaks are. My last injector was glistenning and so were the return lines connected to it. I've replaced them and hope this was the source of the problem. Is that possible?
The metals fittings for the lines at the injection pump are leaking. Any suggestions for stopping that?

The return lines at the injectors are often a leak source, particularly if they are many years old. Clean the area up, and see if the leak has stopped with new braided return hose installed. There should NOT be any leaks at the metal injection lines, though. That is unusual. If the leak is at the injector, make sure it's not the return lines. Strategically wrapping areas with pieces or paper towel can help determine the source of a small fuel leak.

It's also possible to have the injector leak between the two halves of the injector body (this is pretty common when taking an injector apart & putting it back together), but that will have fluid build up in the middle of the injector (by the hex flats), not up at the hose connections.

GSXR,
The question is should I pop balance given the situation and costs below:

I will be running my vehicle shortly on waste vegetable oil from a local Thai restaurant. I have an Elsbett kit arriving from Germany that contains special injector nozzles. My local diesel injection shop went out of business (#?!@#) so now I face an hour trip one way to Cincinnati for pop balancing. The car runs pretty well as is. I am thinking of doing this with my brother (trained as a mechanic, works on his own cars a lot, but never worked professionaly.) We will be doing the rest of the kit together and enjoy getting together. He's getting very interested in WVO too. I have bosio instructions which should work. I am thinking I should forego the pop balancing given the loss of 1/2 day work plus auto rental. Its going to cost at $89.75 per hour. Could easily be $450 job or more. Since its 1/2 hour per injector minimum. Free with the brother sounds pretty good, but no pop balancing unless we somehow got loan of pop balancing rig.

I have thoroughly clean up the engine and I am tracking down fixing fuel leaks. My issue with winter running that I alluded to previously (super cold, starts, but runs like cylinder missing until fully warmed up) may be accounted for. A custom curved hose appears to be leaking and I am replacing with stock hose soon. I am hoping this is the main leak. I have a reproducable problem where if I park with the car pointing up hill, I lose fuel out of the lines (assuming this as it takes 45 seconds of cranking with gas pedal floored to get the car going.) Done it 3 times recently.

I tightened up some of the injector lines at the pump, but there is still seapage seemingly around the plates where these attach. I am going to try a variation on the well known trick of changing the fuel filter and putting ATF in to clean injectors. I intend to add about 75% ATF and 25% ATF based stop leak (most are pure stop leak) to a new fuel filter. I will then run the car for about 3 minutes and turn off over night. The hope is this will swell the seals and contain the leak.

I am having to become a leak Nazi as vegetable oil does not really evaporate. Any leaks will eventually find there way to the ground. Not as ugly as an oil stain, but equally hard to remove. Ran the car on pure canola as a test for about 500 miles with the car unmodified back in August. Leakage with waste may leave the sent of Crab Rangoon on friends driveways. I want to try to avoid this. Have thoroughly cleaned exhaust area and engine to watch for any kind of fluid losses.

Thanks for all your help and suggestions.

What I would do is this: Run the injectors as-is for a few thousand miles. Then remove them, and find a shop that can pop test them (just pop testing takes like 15 minutes and should be cheap). If they test within 5 bar from highest to lowest, and you can't find a shop to do the balancing at a reasonable price, just leave them alone. While it would be nice to balance closer than 5 bar, there is not a huge improvement from doing so. Now, if the difference is more like 7-10 bar (or worse!)... then I would at least have the worst offender(s) re-shimmed to pull them back into spec.

You might consider buying a pop tester and shim assortment... you can probably locate a tester for $200-$300, and a shim assortment for ~$100 or so. Then you can do it yourself, and either keep the tools, or re-sell everything to another forum member when you're done to recoup most of the $$ spent.

In general I don't recommend using ATF in an indirect-injection (prechamber) engine, nor any sealants designed for transmissions. I'd use a healthy dose of Red Line DFC (or 85+) instead (like, a full bottle to half-tank of fuel, or something like that). Fuel leaks at the IP are often the delivery valve seals, which should just be replaced, it's not that difficult. FWIW, when I change the main fuel filter, I usually fill the new filter with Diesel Purge. But let us know how the ATF trick works out.

Well, I am converted to an Elsbett single tank veg oil. It is awesome. The smell of vegoil and dealing with it is heaven compared to diesel. It will be interesting to see if my motor oil is a little less stinky in the future. Quite a project. $3k in my pocket in fuel per year at 15k miles per year.
First off, the aforementioned ATF with stop leak did not do anything. When I converted the car the weekend before last, I had to go after every fuel leak. It made sense to do all the hoses. The big undertaking was fixing the $5000 diesel injection pump. $10 worth of parts for this (rubber o-rings and copper washers), but an extreme amount of pain on my car.
The instructions for replacing the common cause is on dieselgiant and is perfectly applicalbe to the 1993 300sd except for one omission. After getting the line nuts and locking plates off (remove torx bit), the mother bleeper was getting the top part of each line in the pump off. It looked like a something you would undo with your hand. Dieselgiant made no mention of this being a royal beache or requiring special tools. Used two locking plates that match fairly close and plyers. Nada. Hammered with long ratchet extension and hammer (2 man job.) Nada. Move from 6 to postion 5; it took a whole rotation of this to get to where one could just use the pliers. Had to remove the priming lever to get position 6. You do not know pain or suffering until having to take a hammer to a $5000 pump. Yikes. Its finished and no leaks. Replace all fuel hoses in the conversion except for metal lines under the chassis. These will go soon with some hard plastic line from the kit that has a larger inner diameter than the metal lines. Criticla when you hit 20F in the winter and your oil is one step away from gelling. I will be winterizing my single tank setup with some custom stuff.
My injector 1 and 6 nozzles had to be hammered out to do the rebuild. A lot of black gunk holding them in.
My take is that I got no performance increase from the rebuild. My car already had rebuilt injectors from mercedes so they were half the age I thought. The Elsbett injector nozzles do not like straight diesel. Half way through the conversion ran with straight diesel and the diesel sounds were quite loud (on oil no sound, nice!). Elsbett injectors have greater spray pressure to compensate for increased viscosity of veg oil. Truth be told, its hard to give an accurate judgement. Per gsxr suggestion I will probably yank them and pop test/rebuild as necessary. As it stands, my sense is that the pop testing will reveal that they are close to spec.
I'll update in a few months on my pop test results and what benefit I perceive from this.

Yeah, you needed the tool shown below (about $35 from the dealer). And there is a precise 3-stage procedure used to re-torque the barrels. I'm amazed it's running at all if you removed with a hammer, and re-installed them with pliers...!

My brother wanted to give up, but I am very determined and wanted not leaks as veg oil finds its way to the ground. I just ordered a few of the locking brackets as a couple of them got egg shaped! I'll let merc know they should have sold me that tool. We did do the retorquing procedure as Dieselgiant did mention this.

You would not happen to have any sage advice on removing the tank? There are 4 bolts in the trunk. Had these out and hoses below disconnected, but it would not budge. I yanked on it a couple time with my feet on the strut towers. Gave up. I want to add something called a hot rod for vegoil pickup. Take a grinder to a flat portion on the side of the tank and make a hole where I can attach a plate with the rod going along the bottom of the tank. There is an adhesive that will get that job done. I think that tank (since it pulls up through the trunk) may be difficult to work with for this. I'd love to do it in place, but I'm thinking the tank is above the rear axle and not easily accessed from below. Might be a way to get to it by cutting through from under the removeable rear seat. Sounds like fun, no? I need to crawl under the car again soon.

gsxr,
Do the 350sdl and w140 om603s require the injection pump timing to be adjusted? I am thinking that they automatically adjust for the timing belt stretching so this is automatically adjusted too?
Do these cars have an idle adjustment?
While in this vein, am I correct that the engine valves are self adjusting too?

Been searching around and I've not found anything.

603s have a timing CHAIN. No the timing isn't adjusted by itself, it's Mechanically Injected.

Yes, idle is called ELR from memory. Red deal on back of IP.

Valves are hydraulically actuated... simply follow the cam so they can't adjust themselves.

__________________
I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

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