Was on wvo clean the system first. Pull the injectors and have them pressure and spray checked if the cleaning does not improve things. At least it is nothing serious as the sympton went away for a few days.

Serious engine issues are not intermittent generally speaking. Personally I would laquer thinner soak the injection pump as no sense of potentially more crud breaking loose after the problem is solved. Just remove the line before the lift pump. Or remove the return valve and gravity fill the injection pump after the secondary filter.

Pump the laquer thinner in with the primer pump if the relief valve is not removed. Remember volume wise you have to fill the secondary filter as well before the thinner gets to the injection pump. Let it soak overnight. Pump fresh diesel in to send the contents of the pump out the return line into a glass bottle. This lets you see what if anything was in that pump.

I would also put a fresh secondary filter on at this point before hooking back up with the tank. Do not run the engine on laquer thinner. It burns like gas.

after running the car and loosening the hard fuel injection lines one at a time, it appears #1 is the problem.. after loosening that one, the clanking noise actually went away..(?) the engine ran about the same. when i loosened #2-4 the engine died down quite a bit, so it seems #1 injector/cyl is the problem area.
i want to pull the injector and move to a new cyl, but i havnt ever pulled injectors before.. i went and got a 27mm deep socket, but am unsure if i need to worry about replacing the heat shields during the test? or can i just swap the injectors and worry about new heat shields once i figure things out? or do i need new heat shields just to the test?

when putting the injectors back in for the test, do they need to be specifically torqued? if so, anyone have the spec?

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1981 240D ... 265k
1977 240D ... 265k
1977 240D ... 250k

Just for the test I would use the old heat shields. You will know very fast if the injector is the problem. I of course hope it just the injector.

Having mechanical problems on the first cylinder are more typical on the 240ds than on the other cylinders. That said because the symptoms dissapeared for a few days is a good thing.

(( to recap, i loosened #1 fuel line and the knocking goes away and idle doesnt really decrease,,, ))
so now i pulled cyl #1 and #2 injectors and swapped them. i reused the old heat shields.
started it up, then loosened cyl #1 fuel line (old #2 injector), engine idle decreased very noticeably, and the knocking sound was still present.
tightened cyl #1 fuel line
then loosened cyl #2 fuel line(old #1 injector), idle decreased a little, but not as dramatically as the #1 cyl did, but the knocking went away... the same thing that happened when this injector was in cyl #1. i tightened the fuel line and loosened #1 and #2 in order again to confirm results. same thing, when loosening #2 cyl(old #1 inj) the knocking went away.

so, this should mean that the old #1 injector could be the culprit? i assume since the knocking followed the injector, that is where i should start out?

if thats the case, what should be my plan of attack-- a new injector, a new nozzle, try cleaning the injector first? i've never replaced injectors before, so i dont know how it works as far as- can i replace just one injector or do they all need to be replaced at once? i dont have a pop tester or anything of the sort.

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1981 240D ... 265k
1977 240D ... 265k
1977 240D ... 250k

Your choice. Either have the old bad injector repaired or replace it with new,reconditioned or used. Taking it apart and cleaning it might restore it.

But since it has to be checked anyways leave it up to an injector shop to do that. Since the history of the car includes wvo with a past owner I personally would clean out the system as well.

Just in case junk is migrating to the injectors. It almost sounds from your original description like the injector cleared itself once and perhaps junked up again. If getting a used injector remember the pop off pressure is higher on the injectors used in turbo engines. So avoid them unless prepared to have them recalibrated.

I still suspect there is a chance there might be leftover junk from the wvo in that injection pump. Cleaning it out if there is not that big of a deal really. Better option than repeats of this issue. I would not consider putting in a full set or have the injectors all checked. Until I was sure there absolutly is no migration of junk as an issue.

Price the new heat shields at the injector shop. They may be cheaper if they have them.

if i get a reconditioned injector, such as a $50 bosch online, do i need to get it pop tested, or the others tested/matched? or just stick it in and go..?

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1981 240D ... 265k
1977 240D ... 265k
1977 240D ... 250k

just to throw a wrench in your plan, have you checked the timing of the engine yet?

my engine had an idle miss which sounded like you describe and caused smoke like you describe, and it ran rough at idle, but was fine on the highway.

it turned out I had 9 degrees of chain stretch.

replacing my chain caused a dramatic difference in idle quality. the idle miss is gone, and so it the smoke (well, 80% of it

having the injectors serviced is a good thing to do either way, but timing could be contributing to the problem.

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OM617 in a 67 chevy pickup http://tinyurl.com/projectgmbenz

i havnt checked the timing of the engine,- however, the ticking and rough running are at idle and any other speed, it doesnt go away with higher speeds. and since the problem seemed to move with the injector, that seems more like an injector thing?
i am not opposed to checking the timing, but ive never done it before... any leads on a DIY article on how to do it?

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1981 240D ... 265k
1977 240D ... 265k
1977 240D ... 250k

Just check the archives for the pop pressure required and ask them to sell you one of them with it. There are only two recommended different pop pressures for all 123 engines.

I believe we even have a member on site that deals with them. Chances are he does not use the inferior nozzles in his rebuilds.

Will, your diagnosis is spot-on. Noise following the injector and not going away at speed definitely point to the injector.

I'll give you the link to check your timing and then I'll stop hijacking this thread

PeachPartsWiki: Measuring Timing Chain Stretch

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OM617 in a 67 chevy pickup http://tinyurl.com/projectgmbenz

When you get the injector issue settled down I or other members can suggest methods to make a 616 engine the best it can be. It basically is just checking to acertain that the old systems are still up to scratch.

If they are not then restoring them. The best part is it costs next to nothing other than a little time usually.

I too own a couple of 240ds.

nice! thanks that is good to hear! so far with the help of this forum, i've had both 240s running for a year (one for me, one for my GF) and i havnt had to take them to a shop at all, have been able to do all my own maint and repairs- i've come to appreciate their design immensely and it makes me confident driving them that if something goes wrong, i have the ability (with the help of you guys) to get it running again. with other "newer" cars they always felt a mystery and at the mercy of mechanics. it feels good to be in control of my own destiny
its nice having 2 of the same car, so once i learn how to do something it will be piece of cake if it happens to the other!

on the injector note- i like your suggestion of just buying an injector from the shop that is already calibrated to spec. is it safe to say that since the car was running smoothly before that the other injectors are popping close enough to spec that i can just install the new one and not have the others cleaned/balanced ? i realized cleaning/balancing is prob best, but of course, i'm trying to tow the line of keeping my cars happy and my starving artist lifestyle...
-i think im also worried that if i bring the other injectors to a shop they are gonna try to tell me they need more than cleaning and it ends up being a $200+ bill.... if i can replace a single injector now and deal with another going in the future that is best on the budget.....
i've read the dieselgiant tutorial on taking apart & cleaning your own injectors and feel i could tackle it, but i assume then for sure they should be balanced once im in there messing with them,,, i'd rather leave working things alone if not broke..??

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1981 240D ... 265k
1977 240D ... 265k
1977 240D ... 250k

If fuel milage is good and there are no strange noises or excess black smoke at idle then I agree. The money not spent will find a new home usually without much problem.

Technically the injectors should be bench checked every 100k. I suspect the vast majority never have it done.

Garages and cars are such a loosing proposition for many owners today. Many just dump their cars when the warranty is up. On old cars garages are usually a real cost issue. It is fairly safe to say the majority of site members repair their own issues.

Locally it is 7 to 12 thousand to reshingle a roof. It is about a thousand dollars for materials and a couple of days time to do mine. I did half of the roof last week on a nice day. This applies to many things in life.

Glad to see it isn't just a local issue. Around here it's awful. Some shops don't want to touch stuff more than six years oldm for whatever price.

Those that do are increasingly facing serious blowback from customers when they get the repair estimates. Sometimes people end up selling the broken down vehicle to the shop or trading it against the bill... then they go out and buy (more probably, lease) a new car.

There are massive inventories of used cars around here now, except for the most economical models, which can always be sold. Seems that everyone wants new cars and new homes (the resale market on older homes has gone into the toilet, while the new/new-er construction is booming on new and used sales).

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Mac
2002 e320 4matic estate│1985 300d│1980 300td
Previous: 1979 & 1982 & 1983 300sd │ 1982 240d

“Let's take a drive into the middle of nowhere with a packet of Marlboro lights and talk about our lives.” ― Joseph Heller, Catch-22

i replaced the suspect injector today. -- for $ reasons, i'm gonna save up to get all 4 injectors reconditioned,, so for now i got a working used injector for $10 and threw it in to get back on the road.. car started right up and runs good no more put put put or nailing sound - there is a slight clank intermittently when idling... which maybe was there before,,? but for sure it is running smooth and no constant clank clank that was happening before. i only drove it a little bit today, so we'll see in the next few days how it goes,, but... i think that it was a bad injector and im on my way
thanks for everybody's help!!

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1981 240D ... 265k
1977 240D ... 265k
1977 240D ... 250k