LOUD diesel rattle on startup

[Clipper]

Progress, but...the saga continues...

My original post, "4300 dollar repair bill"
http://www.dieseltowingresource.com/showthread.php?t=6417

I had white smoke on startup...You guys said "air in the system,"

Couldn't find air leak, 6.5 expert diagnosed it as a bad injection pump. Changed out pump, problem not solved. After weeks of wrestling with the problem, it seems that several of my fuel hoses started leaking at once...so...YOU GUYS WERE CORRECT! AIR LEAKS!!! ):h :mad2:

I have (had) clear braided polyurethane hoses (due to my WVO setup) that are only a year old. Because of the braid, the leaks were acting like a check valve...letting air in, but not showing a leak under pressure. Finally the leaks got worse and started to leak fuel out, that's how I diagnosed the problem.

So I had the expert put the old IP back in. He warns me that the timing ring is sticking intermittently...swapped out stepper motors, the timing is still not advancing...sometimes. (intermittent problem.)

But...he is willing to buy back the new pump from me, leave the old pump in, and take it off the bill.
And the truck is running fine with the old pump, EXCEPT:

When I start it, hot or cold, it starts easily, normal little puff of white smoke cold. Runs well for about 5-8 seconds, then suddenly the idle RPM drops for about a second or two, and I get a LOUD diesel rattle. After a second or two, the loud rattle stops, and everything is fine for the rest of the time I'm running it.

If I use no throttle on startup, the loud rattle (and RPM drop) lasts for maybe two seconds.
If i give it a little throttle, rev the engine a little, the rattle comes on quicker and is much shorter...maybe a half a second.
This happens every time I start it...whether It's been shut down for five seconds or twelve hours. Hot or cold.

I'm thinking I still have a slug of air going through there somehow, though I can't imagine how...I decided I could live without clear hoses, so I've replaced all the hoses with Goodyear J30R9 (the high-temp, chemically-resistant, blue-liner fuel injection stuff.) For it to happen so soon after startup, any leak would have to be pretty close to the IP, or maybe in the IP itself (few seconds for the air to hit the injectors.)

Or could it be that the timing ring is sticking a little bit, for a second or two, on startup?

Or...??!! Any and all comments/theories welcome...Thanks....

 

[JMJNet]

You said you are using WVO, may be you need to troubleshoot that system first.

WVO in the 6.5 IP does not agree to well with each other. There is an optical sensor in the IP that does not like anything that is not clear. At any rate, have tried running it w/o the WVO just straight diesel and see if that still happen.

Need to eliminate all the variables one at a time to determine it.

Just my thought.

 

[Clipper]

Hi, JM,

Forgot to mention that...I have not been running on WVO since this happened...only diesel with Stanadyne blue additive.

In the original white smoke on startup problem, it was ONLY happening on diesel...running on VO, there was no white smoke on startup. A couple of times, when the air leaks got bad and the engine died, I had to switch to VO to get home...! (Once I had to do that on the new IP...!)

And also, I NEVER start it on cold VO...in fact, I never switch over until the VO gets to 160 degrees (and I have a temp guage in the cab that measures the oil immediately pre-IP.)

So this is definitely a diesel problem. Good thought, though...I'll try running on VO for a couple of days and see if it clears up...!!

Thanks....

You said you are using WVO, may be you need to troubleshoot that system first.

WVO in the 6.5 IP does not agree to well with each other. There is an optical sensor in the IP that does not like anything that is not clear. At any rate, have tried running it w/o the WVO just straight diesel and see if that still happen.

Need to eliminate all the variables one at a time to determine it.

Just my thought.

 

[Dan Hunter]

I'd be interested in how old your glowplugs were and if they're in good condition. I'm running 60Gs and an override button for extended glow. If I don't use the extended glow on cold days, it starts in a very disorganized fashion with a little unburned fuel smoke puff.

 

[buddy]

Mine would kind of do that when it was dying a few seconds after starting, starved of fuel by the shutoff solenoid. Not that the solenoid is your issue, just that sounds like maybe air and not enough fuel like youre thinking.

However, Glo-Plug maybe? My Glo-Plugs will come on for their cycle but then also cycle on twice for one second in the first like 8 seconds of idle. Maybe that is keeping my idle smooth.

I also wouldnt discount your timing theory though, since Ive had the chance to watch about 5 chips work in my truck, and see the effects of timing at idle and idle fuel rates. You could check the idle IP timing if you observe it with a scanner or just a USB cable and software on a laptop like I have. Also check TDC Offset, should be between -.25 and -.5, unless its been advanced to like -1.94. I have found that idle IP timing of about 3.5-5 degress is good for smooth quiet idle, less than 3 is not good about 8-9 is great for off the line acceleration. Fuel rate at idle should be about 6-8mm3, any less might be an issue and could confirm you have a fuel issue. Both are easily checked with the Engh Motors $100 USB adaptor cable or maybe cheaper ones elsewhere.

One check you can do Ive heard of to see if your IP is maybe getting quirky, is revving it in park, and trying to get it to 2000 RPM and hold it there steady for a few seconds. If you cant do it your IP is probably flaky. Its kind of difficult to do even on my new IP, but doable.

 

[qwomack]

Sounds like the stepper motor movement is limited by something. The stepper motor is on the passenger side front of the IP. Get a flash light in there and make sure something hasn't jammed up under the linkage.

 

[JMJNet]

Glow plug may be an issue if it is really bad. I don't think you need an extended glow in San Diego, CA. I think you may want to go back to some of the critical test with the diagnostic checklist just to be sure that you are not missing on something.

 

[vail426]

I'd be interested in how old your glowplugs were and if they're in good condition. I'm running 60Gs and an override button for extended glow. If I don't use the extended glow on cold days, it starts in a very disorganized fashion with a little unburned fuel smoke puff.

X2

 

[buddy]

Any luck? When did you install the remote FSD? Did the mechanic ground the FSD wire harness back to the IP? And is your FSD grounded in the bumper?