Finally got around to testing, and then replacing the glow plugs.. 4 stuck.

MJGenay

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Alright gentleman. I'm hoping I get my truck back later this afternoon then I'm going to start digging into that. I asked my mechanic his opinion and he thinks its the heat shroud on the down pipe from the turbo... idk what to say about that. The issue did begin directly after the turbo install so maybe I'm just a moron, but it has also become progressively MORE of an issue. I don't quite understand why it comes and goes and only seems to be an issue at lower RPM's when it is cold (same RPM's when warm are fine). Maybe the engine just moves in a different manner when it is cold. I didn't want to ask him any more questions cause I can't afford him spending more time on it.

I'll report back this evening once I get to tearing into it. At any rate I'm going to check the connections on the sensor and the IP. To me at least, this makes more sense being a cold timing advance issue.
 

IDIBRONCO

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Here's one way out in left field. Does it make a similar rattle when you shut the engine off? I'm wondering if you have a bad dual mass flywheel. That can make a terrible rattle upon starting the engine and it can also (often will) cause the engine to shake badly.
I was thinking earlier today that , at the point, you probably don't have any air intrusion or fuel drain back issues. The engine performance doesn't change like it does with air intrusion. You also pulled your fuel filter after sitting for several hours (possibly overnight?) and it was still full. Your symptoms are a rattling engine on start up that's accompanied by a bad shaking of the engine. This is why I'm trying to look at other options.
 

MJGenay

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Here's one way out in left field. Does it make a similar rattle when you shut the engine off? I'm wondering if you have a bad dual mass flywheel. That can make a terrible rattle upon starting the engine and it can also (often will) cause the engine to shake badly.
I was thinking earlier today that , at the point, you probably don't have any air intrusion or fuel drain back issues. The engine performance doesn't change like it does with air intrusion. You also pulled your fuel filter after sitting for several hours (possibly overnight?) and it was still full. Your symptoms are a rattling engine on start up that's accompanied by a bad shaking of the engine. This is why I'm trying to look at other options.
Okay so that could be it however it doesn't seem to do it when I shut the engine off. I let the truck sit all day, got home from work, and got under there. I put a bunch of self taping screws into that heat shield (the one on the bottom of the cab by the exhaust pipe) and no dice. Bent the heat shield. No dice. Went under the truck and honestly it sounds like it might be coming out of the bottom of the engine or maybe the engine/tranny joint. Might be passenger rear on the engine. Hard to tell. Really hard to tell when its so damn loud.

It is confusing as it could very well have been and still be this damn heat shield. There are obvious rub marks on the cab heat shield from the down pipe.

Nothing seems to be shaking too badly but maybe I'm just not noticing it.

Here is the question guys. Should I stop turning this thing on until I'm sure I have found and fixed the issue? Am I potentially damaging the engine?

PS. The truck started in like 1.5 cranks so I doubt fuel issue too.
 

MJGenay

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This just makes me think DMF all the more now.
I just got under there and pried on the heatsheild while it was rattling, no change. I paid more attention on shutoff, it rattled as it passed through 300 RPM but it was a damn quick rattle. Not sure if that means anything or not.

I shouldn't be expecting anything engine related right? Like internals?
 

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If it was the DMF, it should not rattle when the tranny is in neutral and the clutch pedal is not pressed? Or it should change the rattle correct? Or maybe it will not rattle if the clutch is kept pressed in?
 

MJGenay

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The sounds this guy has, that he describes as a rough idle, is pretty much exactly the sound I have. I hit the pedal and it disappears. Makes me wonder if it is that cold timing issue. His sound start at 7:30
 

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If the tests are simple, I don't see any harm and trying them out. Pull the correct wire off the pump, that should get rid of the cold advance. You don't really need it anyway, I haven't had mine connected for years now.

The clutch pedal tests should be easy to try also.
 

MJGenay

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If the tests are simple, I don't see any harm and trying them out. Pull the correct wire off the pump, that should get rid of the cold advance. You don't really need it anyway, I haven't had mine connected for years now.

The clutch pedal tests should be easy to try also.
Yeah I'm about to go fool around with the clutch. I still don't quite understand this cold timing advance. I know there is the cold high idle, I understand that and I know that recently stopped working. What exactly am I looking for with the cold timing advance? How does that affect things? I should just unplug the sensor for it that is behind the alternator?

If it was working and I unplug it how should that affect things?
 

franklin2

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When 12v is applied to that wire, the pump advances the timing a set amount. I don't exactly know what it does inside the pump, but I am assuming its some sort of solenoid inside.

The sensor is fed 12v. When the engine is cold, it passes this 12v to a "y" connection in the wiring, feeds the fast idle solenoid AND the cold advance solenoid wire going to the pump.
 

MJGenay

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When 12v is applied to that wire, the pump advances the timing a set amount. I don't exactly know what it does inside the pump, but I am assuming its some sort of solenoid inside.

The sensor is fed 12v. When the engine is cold, it passes this 12v to a "y" connection in the wiring, feeds the fast idle solenoid AND the cold advance solenoid wire going to the pump.
Got it. So I tried that. The rattling didn't seem as bad (in fact it seemed much less but still there off and on) with the wire disconnected however it could be the engine is just getting warmer....

The clutch, when depressed, if it is supposed to have an instantaneous affect, it doesn't. There might be a little correlation with the clutch depressing and then a second later the rattling seems to disappear but it is hard to tell as the rattling on the whole doesn't seem as bad now. I don't know if that is due to me removing the plug or the engine getting warmer. I'm going to go experiment with plugging that in again and then removing it.
 

MJGenay

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I'm going to have to wait until tomorrow when it is dead cold and then try this again to test the clutch and see if that has an affect.
 

IDIBRONCO

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I've seen bad DMFs that would rattle on start up for quite a while. A quick blip of the throttle will usually make it stop.
You have mentioned that the last owner replaced the pump and injectors. You didn't mentioned whether or not the timing was ever set correctly or even checked. That certainly wouldn't hurt. His timing was definitely off due to the blue looking smoke coming out of the exhaust. Was that the source of his rattle and rough running? Maybe, maybe not. That sounded just like a bad DMF to me, but it's hard to be sure over a video. He does have a ZF5 transmission. He was also wrong when he mentioned that air bubbles coming from #1 injector return to the filter means that the injectors are leaking air. That can't happen because they have fuel running through them, not air. They can't suck air because they're under pressure when the engine's running, not suction. Now if there was an o-ring leaking, letting the fuel drain back to the tank when the engine's shut off, then you could get some air going through that line when the engine is first started. If that's the only leak, the bubbles would clear up after the engine runs a while and pushes the air out of those lines.
The DMF rattles because it has springs that act as cushions between the two pieces. When it's in good shape, the springs will compress and release while keeping the two pieces working together like one piece (basically). When the flywheel gets to be "bad", it's almost always the springs get weak and then they stay compressed which allows the flywheel parts to slam back and forth, causing the rattling noise. The two pieces that are slamming back and forth are also throwing the engine out of balance for a couple of reasons. 1) the balanced parts are no longer in the proper place to balance the engine. 2) you have a heavy piece of metal that is moving against the rotation of the engine and then quickly moving with it faster than the engine internals are moving. That's why the rattle mostly happens at idle speeds and slightly above.
One more thing to point out about that video. Notice that he said that he does not have any air bubbles going through the clear hoses. That completely throws air out of the equation for his example. If your rattle sounds exactly like his does, that just adds one more point in favor of a bad DMF in my opinion.
If you want to eliminate the inspection cover as a source of the noise, don't add more screws to it, just remove it. Then it can't make any noise. You can also see if it was being rubbed by the flywheel because it will have clean scrape marks from being rubbed. While yo u have that cover off, you can check your flywheel. You can grab the clutch and see if you can move it back and forth in a circular motion that runs along with the flywheel. If you can move the clutch, the flywheel is bad. I hope that makes sense.
 

MJGenay

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I've never been inside a flywheel cover so I'm not sure I'll know what I'll be looking at. I'm going to do some more research this evening and see what I can learn. I don't quite understand the direction of movement I am looking for from the clutch to test the flywheel.

I actually think he set the timing correctly. When and where I purchased the truck it wouldn't smoke at all upon start up except a quick blip of black smoke. That was at 1200 ft elevation and 60 degrees. Now I'm at 9600 feet and its currently 15 degrees out. I just assumed I'm running rich hence the grey smoke until it warms up. That make sense or am I wrong? The smoke seems to be worse when it is colder out. Once the truck is warm it mostly disappears, at idle I might have a slight amount of grey smoke coming out the exhaust.

So here is an issue. I drove the truck 700 miles home or whatever, no issues. Got it home and didn't drive it until I changed all the fluids and installed the turbo, and bam, my synchros dissappeared from 5th to 4th in the tranny within a couple times of driving it. Now I'm double clutching from 5th to 4th so I don't grind. I figure with my limited knowledge if I'm changing the DMF to a new SMF then I need a new clutch. Don't I also need a new clutch if I drop the tranny and have it rebuilt? Damnit. None of that is affordable at this point in time and I really don't want to pay to have any of it done twice.
 

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