This 603 engine doesn't sound good to me...
 

Please see (listen to) the attached PDF which contains a sound file of my 603 engine (1987 300d turbo).

I recently had the injectors rebuilt - first time ever after around 335k miles (unless it was done in the first 50k before I have records). The injectors were at the very bottom of the pressure range spec (all between 133-135 bar) - they were set after rebuild at the mid of the factory range (142 bar +/- 2 bar). I also adjusted the alda as per the many other threads.

The thing drives like a champ - seems to have more power, a bit quicker, etc. but, it sounds very noisy vs. what I recall before my "upgrade". It also smokes a little just sitting at idle which I don't recall seeing before and runs a little rough (sitting in the cabin).

I'd appreciate hearing some comments about the sound - I can live with it if it's not the sound of something wrong or going wrong...

It is a bit clatter clatter. Have you good lift pump pressure? Have the filters been changed out & fuel system cleaned ? How many miles have you done since the work?

I can't hear anything (never have seen a sound in a pdf before and can't find yours) but the smoke is, just based on this post, entirely normal. Diesel smoke is caused simply by the injectors providing slightly more (ranging up to extensively more) fuel than the available air can burn. At idle, almost ALL diesels smoke if they are configured to deliver their "normal" amount of power under acceleration rather than a limited amount. You've just had your injectors brought up to spec from previously under-delivering fuel, and by adjusting the alda out, you've SIGNIFICANTLY increased the amount of fuel your engine has access to. This is a good thing for acceleration, but does increase smoke slightly.

Point is, wouldn't worry about the smoke. Nine times out of ten, when you get a seat massage from the engine's idle, it's the motor mounts getting worn out. You can speed up the idle a hundred rpm or so and the shaking should be "hidden" although not "fixed".

No idea about the sound since I can't hear it.

Only about 3,500 miles since the work was done, time for an oil change again. I changed the oil and replaced the inline and canister fuel filters at the time of the work. I don't know what it is or how to test the lift pump pressure - oil pressure is pegged at 3 except for at idle pretty much. I noticed the louder, "clack"itier sound immediately but it seems to be getting noisier (or maybe just concerning me more...)

Thanks for thoughts on the smoke - that's not a big concern, but I thought that it might be related. I don't recall it smoking on idle much before, though. Smoking on acceleration can be a benefit - such as when you've got a pesky tail-gunner on a two-lane road.

If you open the pdf, there should be a little bar near the top with a pause/play button (it is kinda small - 2nd button over and you may have to click it 2x to work). Sorry if it's not there for you, maybe it requires some computer hardware to work. Sound file was too big for the normal attachments and I didn't have any way to make it smaller.

Will be interesting to hear it after an oil change.
The sound file worked for me. didnt know you could make a sound PDF

Diesel Purge.
 

Some folks pooh-pooh it, but it works. I was wondering when I was going to have time to go through the injectors on my '87 sedan, 'cause they were nailin' something fierce! I ran a can through, and it sounded (sounds) so much better I've moved the injector rebuild WAY down on the to-do list. WAY, WAY down... as in forgotten about it entirely.

Jay.

For the $10 it's probably an easy thing to try but in theory that's what I just did - cleaned the injectors, replaced the hoses, replaced the filters, etc.

So, could I have messed up the timing as a result of setting my injectors to a higher pressure? I.e., maybe it takes a split-second longer for the pump to build up the add'l pressure to pop the injectors so now my timing is off? And, if so, how bad for the engine in terms of wear, etc.?

Also, it does start a little rougher than it used to. I replaced all of the glow plugs at the same time as this work and usually after a GP replacement it starts right up when the light goes off (after just a few seconds). Now I need to wait until the SRS light goes off (about 3x as long) or it starts pretty rough (acts like a plug is out).

What is "nailing" exactly? I realize that a sound file is pretty hard to diagnose but do you hear it here? I have seen causes for nailing (retarded or advanced IP timing, fuel leaks, etc.) on the forum but I don't know what it sounds like or what the result is to the engine over a long period of time.

If there's a ticking sound you don't expect, it might just be a loose Heim end on the belt tensioner damper. Push on the upper Heim end with the engine idling and see if the ticking goes away.

Sixto
87 300D

ESound file doesn't work for me, either.

If anything your timing is RIGHT now per mb/bosch performance specs and delivery/pop pressures.

New glow plugs can fail, too.

Take a chisel or old screwdriver and pound it with a hammer into concrete a few times a second. That's what nailing sounds like.

I don't hear nailing in the file. Maybe a noisy lifter or tired damper Heim end (did I say that already?). Or maybe your recording equipment and my PC cannot faithfully reproduce the sound of nailing :eek:

I have no trouble listening to the file except it doesn't start on its own. I have to click pause then play to get it to start.

Sixto
87 300D

I recognize the footsteps you are about to take, did this with my own 603...

Put in new Monarks all around set up to 2000psi. More knocking on cold starts.

Odds are your timing is off after doing the injector job.

Chain stretch (delays timing) plus soft injectors (advance timing) work in harmony to balance timing and keep it near the mark. You changed the injectors, now you have a net delay. So play with the timing (advance it) to compensate for stretch. It will still smoke a bit at idle.

Now put a new chain in and set the timing "correctly" if you feel the need using drip tool, or do it by ear and your seat dyno (I do this works great).
When I put in a new chain, timing immediately was way too advanced and loud knocks, and I had to back it off.

The new chain addressed light smokey issues at idle... because now the valves are now working correctly again w.r.t. the rest of the parts in the cycle.
With or without ALDA didn't help with idle smoke. It was the chain. Car is without ALDA now, and I can make smoke on demand with the pedal, until the turbo kicks in and provides plenty of air.

I did the new glow plugs too while I was in the vicinity. Car now starts like a champ with one crank revolution. It seems using any glow is optional.. will start cold. Never did do a compression test, but it must obviously be good.

HUGE TIP: there's one bolt at the rear of the IP that needs to be slackened, in addition to the three obvious bolts at the front of the IP that you loosen before doing timing adjustments. Get at that rear bolt before you twist the IP. I didn't see it, twisted the IP, which cocked it so slightly to unseat the big O-ring at the front.. and had an oil gusher at that O-ring. The car didn't really need a new O-ring there, the old one was pliable not brittle. But many people say get a spare on hand before you try timing, in case yours cracks. Then you need to pull the pump and put the new ring on. I got the whole seal kit for the pump while it was out and did top valves too, even though none of them were leaking.

Any air in the fuel lines ?.

My w124 uk non turbo 1990 was drawing air through the pre filter and this caused it to rattle a bit at idle,it sounded like one or two lifters were clattering and this would come and go at idle.

I swapped line in and return for now and it became smooth instantly.

I had a similar thought but nothing to back it up and thanks for the tip! I need to check the timing anyway... Not sure about changing the chain, though - after 340k miles doesn't everything sort of wear in together? Seems like something that you do every 100k or you don't do it at all and I'm always concerned about getting a replacement part that's worse than the old part I've got. I've never taken her to a shop (had a bad experience as a kid with another car) and changing the chain is probably beyond my capabilities. I'll go dig around on the forum a bit to see what it takes.

The thought crossed my mind (read about that elsewhere here) but wouldn't it work it's way through by 3500 miles? It was pretty bad for a hundred miles or so as I recall but got much better at some point.