Without sophisticated test equiptment, simply driver's door ajar and the dome light on: Its VERY OBVIOUS that when the glow system turns off, the problem starts.

Leads me to beleive a clylinder is off. Either compression (ugh) or prechambers, am proceeding to check prechambers... HOW?

Do I simply crack each line and wait for the noise to go away? By stethoscope, its #2.

And TO BE CLEAR...

I CAN RUN THIS ENGINE W/O AN INTAKE ON!? This is what I plan on.

Oh, saved the hose from the old shop vac. Just ran the car in the garage for a few mintues vented out under the garage door, with NO SMELL. Makes it easier for sure.

OK engine , here I come. Was going to chase down sensors, but... its mechanical ...

Glad you came around.

See post #2.

Bri, I had to start "at the beginning", . Especially on something as new to me as this. I'm on #2 now!

>>Its VERY OBVIOUS that when the glow system turns off, the problem starts.

That's impressive! - It's always good to hear of diagnostic steps that tell you something useful, and cost absolutely zero to carry out!

If you plan to run the engine without the inlet manifold, the only note of caution I would sound is to make sure that all of the vac pipes are well plugged - so you can be sure that the shut-off valve on the pump will work when you turn the key off!

Its too bloody cold today, even in the garage!

You got that right. The SD needs a new lamp on the right headlight........and it's too GD cold for me to accomplish that...........

Well, cool that it runs w/o an intake. Uncool that I can feel a "puff" as I put my finger into the intake ports while running. Worst on 4,5,6 than on 1,2,3.

stopping each cylinder by cutting off fuel only caused it to get rougher.

Judging by the gas escaping past the intakes, there is likely a really bad ex valve in the mix somewhere.

I'll do a compression test only to see the wet/dry comparison as I decide whether to pull the head, or pull the whole engine out. Hate to put a freshly machined head on a poorly sealing block. ANd would rather diassemble the long block on my stand anyhow.

Man, didnt plan on an engine overhaul just yet!

any trick on the valve job /head machining? Any competent machine shop can handle this?

THNX.

>>Uncool that I can feel a "puff" as I put my finger into the intake ports while running. Worst on 4,5,6 than on 1,2,3.

On mine, it was really obvious. From cold, I was getting exhaust smoke being pushed right back out of the inlet port.

I found that the inlet valve seats on No 6 had sunk into the head. The seats on No 5 were showing darkened patches, which is a sign of imminent failure, so I had them machined out too.

If you aren't getting obvious exhaust smoke coming back up out of the inlet ports, perhaps a cylinder leakage test would help you pinpoint where the problem is - it might also give you an idea of the state of the pistons, rings, and bores, which might alter your decision to even begin the work.

I used an ordinary machine shop to replace the seats, I didn't get the head skimmed, because it looked good, and is water tight.

Hold on a sec, before you pull that head. I find it very significant that the car runs great during the first part of the glow cycle, and then starts to act up. To me that rules out injection, which I think the consensus agrees with.

On my '95, there is a distinct afterglow period. There is the main glow period, which is significantly longer than the glow light lasts. When it's below 32, I generally glow until I hear the relay click and, as you mentioned, you can see the dash lights and overhead light brighten. Then I hit the starter and it fires right up, instantly.

But then you have another period of time when afterglow is occuring. I noticed it first when I was leaving for work on cold dark mornings, after I started, I immediately start to drive gently (after checking oil pressure, etc.) but no period of sitting idling more than a few seconds. After 30-40 seconds or so, I used to see my headlights suddenly brighten - clearly some electrical load was being shed.

I put my DVOM on to voltage and measured the voltage in the electrical system by using the lighter socket while driving, and sure enough, the voltage jumps a significant amount when the afterglow quits.

Now, once in a while I will have to idle the car for extended periods after a cold start, for example when leaving an airport parking lot and waiting at the ticket payment booth. If this whole sequence occurs without being able to drive (and hence really start to warm up the engine), I get definite nailing when the afterglow quits, and the 606 is not happy. Runs like crap until it gets warmed up, after which it's fine and not nailing any more.

My suggestion is to put the car back together and make sure your glow plug relay is OK. I would purge it and give it an italian tuneup or two to really clean out any carbon, etc. See if that helps.

My car has 250K, and I make sure to wind it out at least once a week. Mat it through 3rd gear at least.

Good luck and let us know your progress, I'm very interested in this.

Rgds,
Chris W.

Oh yeah, don't most diesels have some definite valve overlap, which could cause the puffs you are feeling out the intake ports?

Hmmmm. What Chris says is very interesting. As I have already said, I have the same model and experience the cold weather nailing as well, but I haven't tracked it enough to see a pattern. I'll start giving it a closer look and will try to confirm if mine exhibits the same pattern. My plan has been to redo the injectors once it warms up, but I am definately interested in seeing how this one plays out.

__________________
'95 E300D ("Tank") - 231,000 miles
'79 240D ("Biscuit") - 197,250 miles (Sold)
'83 240D ("Ding-Ding") - 217,000 miles (Death by deer)
______________________________________

"Back off, man. I’m a scientist” ~ Peter Venkman

These injectors are fresh, new nozzles. I've been running bio mix, sometimes as much as 100%, so I think the system is "clean". I did a purge whenI first got the car 10K ago. No change.

There is no "afterglow" period here. THe GP's shut down, the dome light brightens, and the heinousness begins.

I will fire the engine to warm it this am, and complete a wet/dry compression test as planned. I cant do a leak down as I have no compressor here.

Have to get moving here, if anything needs machined, as I'd like the car back in service soon. Sure prefer it was a GP relay , and not a valve job. But with 235K on the clock, a valve job isnt odd. I'll edit this post later with the test resutls. I will also check the voltage through the GP system, to detect any afterglow, before I disarm it for the compression test. Which, I beleive, will show poor sealing.


Even in summer, when fully warm, the engine exhibited an intermittent nail at rpm. Particualrly when cyulinder pressure was up, i.e., into the throttle. Certainly something an ill sealing ex valve would do.

Yanking a cylnder head and having it gone through is still cheaper than $1200 for an IP rebuild.

I also found the IP slightly moist. It had been bone dry.

BTW, I did buy that $100 " Diagnostic Manual for 606.91X engines" and sent it back. Not much there that the FSM didnt have, and certainly nothing as expected, as simple, as. " troubleshooting cold idle nailing". Still await a credit from books4cars.com

[quote=WINGAS;1750707]These injectors are fresh, new nozzles. I've been running bio mix, sometimes as much as 100%, so I think the system is "clean". I did a purge whenI first got the car 10K ago. No change.

There is no "afterglow" period here. THe GP's shut down, the dome light brightens, and the heinousness begins.


Just finished doing the delivery valve seals on my 96 e300d, and ended up with similar results. Prior to the job, engine was quiet at idle, but now it sounds like a diesel...with minor clacking. No problems with smoke, power, performance or sounds at highway speed, just makes a sewing machine sound at idle, or when driving about 15 mph and taking your foot off the throttle. I have read most of the posts regarding this issue, and hope that it will go away with time. The one thing I did notice was the fact that when the engine is started from dead cold, the sewing machine sound will not be present while the glow plugs are engaged. Once the after glow process is finished, the sewing machine sound is immediately noticed. I have a scanguage attached, and from a cold start, the afterglow will be activated for approximately 1-2 minutes. The scanguage will indicate a voltage of about 11.8 while the afterglow process is operational, and then jumps to 13.6 when the process disengages. Hope this gives you some insight into your issue

__________________
96 E300d

Just before my last change of engine oil (it was on semi-synth) I got exactly that noise on overrun as the revs were coming down, engine hot.

With Mobil 1 in it, it doesn't make that sound - ever.

I could not find the pre glow sytem diagnostics anywhere on the FSM. But anyway, battery must be low as I get 10.8v for a minute and then a relay clicks it to 13.5v. I had that on for two mintues.

Even though the GPs tested via resistance, there might be a bad, one two or three.

The question is, do I pull them from a hot engine, or a dead cold one? Anyway, need to run it for a bit and pull all the injs out now.

Well, it always seems a tool holds me up. This time the el cheapo US General ( made in the PRC no doubt) injector adapter. Whose "nut" is too large to fit down the hole, hitting the cover. Dont dare spining the engine with the cover off, as assume the most effective oil system will create a mess.

One prayer answered as I just tried # 4 glow plug with a 12mm socket. Like most rusty bolts, I tighten a schooch first, then back it off. It was LOOSE! So I proceeded to back #4 GP all the way out.

#4 cylinder tests at 330 psi on 6-7 "pumps". Holds it too.

All the other 5 GP's are tight as nails, and I'll undoubtedly break one , or more off.

Yet judging by the gunk/soot on the few injector tips I pulled, after a scant 12K miles, I wouldnt doubt the GPs are not functioning properly. I know the harness is delivering the voltage to them.

They tested with a bit more resistance warm, 1.5 ohms or so, vs 0.6 ohms cold.

Either I grind/cut the adapter, or pull the other 5 stuck plugs to complete the compression testing. For now, they've been " Thrusted" with penetrant. And the engine is getting cold.

Flying over to Reading UK end of next week to visit an ailing uncle, hope to post before then.