Knocking and gray/white smoke

[Rockranch]

I've been chasing this problem around for a while now and could use some suggestions before I head off to the dealer. I have done many searches on the forum and haven't been able to find any posts that address what I seem to be experiencing.

I would, occasionally, get a knocking sound from the engine, with white/gray smoke. It has gotten progressively worse.

When it first started doing it, I added some Howes diesel treatment and that seemed to clear it up. A ha! An FCA problem, so I thought. I swapped out the FCA back in October. We took a 2,000 mile trip, towing our fifth wheel. All was well until mile 1,990. Then the knocking/bucking/smoking started again. I pulled over, turned the truck off, bypassed the TST tuner and restarted. Problem gone. It must be the tuner, I thought. A few days later, in the interest of testing, I plugged the tuner back in and took it for a drive. No problems. Back to square one.

I called TST and talked to the boss. He suggested a few things, which I tried. Tuner bypassed, then rail pressure wire from tuner disconnected, then tuner harness removed. The problem remained and has gotten worse.

In the last month I have replaced the fuel filters, FCA and taken the truck back to as near stock as possible. The Snow meth injection is still installed, but turned off.

No codes, oil level remains normal. Can happen when revving while standing still. Mostly happens when accelerating in gears 3,4,and 5. If I feather the throttle, I can make it stop. I should add that it seems to crank longer than it used to before starting.

Anyone have any thoughts?

Thanks.

 

[p-Bar]

Long crank time seems like injector(s) what is the rail pressure at crank? You said you changed filters what is fuel filtration setup? I see it's an 03, are you still running the canister mounted fuel pump? Do you have a way to monitor the fuel pressure (low side) ? The bucking sounds like it's running out of fuel. What happens to the rail pressure when it starts to buck?

 

[Rockranch]

Fuel filtration and pump is a Fass 95 titanium. I don't have a fuel pressure gauge on the low side and, without the TST hooked up, I don't have a rail pressure gauge.

The bucking, knocking, smoke all happen together. The knocking and smoke seem like too much fuel at the wrong time. Like spark knock/pre ignition in a gasser.

By longer crank times, I meant a second, or two, as opposed to nearly instantaneously.
Thanks.

 

[p-Bar]

Without being able to monitor the fueling it makes it tough to troubleshoot . You said you pulled the wire from the rail pressure from the tuner. The tuner doesn't monitor that?

 

[Rockranch]

The tuner does monitor rail pressure, but the tuner has been completely removed from the system, to eliminate it as a cause of the problem.

 

[p-Bar]

If your thinking it's not an issue I would hook it up to monitor rail pressure.

 

[Killgore]

I would be tempted to measure the Ohms on each injector and see if you have one that is 0.5 or greater.
- Ed

 

[Rockranch]

If your thinking it's not an issue I would hook it up to monitor rail pressure.

I'm thinking about that, but it is a lot of wiring to hook up, and it's raining. I might try my scangauge II. I think I can get rail pressure on it.

 

[Rockranch]

I would be tempted to measure the Ohms on each injector and see if you have one that is 0.5 or greater.
- Ed

Where would I measure that? Can I do that at the plug on the head, by disconnecting the plug from the harness? If so, which two pins per injector?

Thanks.

 

[Killgore]

Rockranch, I'm not a tech so someone else with those credentials will have to step in. I did have injector issues and the bad injector was found using an ohm meter. Rather than replace just the one injector, I bit the bullet and replaced all with new Bosch injectors based on my mileage and on the advice I received here on TDR. An expensive decision, but I believe the right one. I wish you luck. - Ed

 

[Rockranch]

Rockranch, I'm not a tech so someone else with those credentials will have to step in. I did have injector issues and the bad injector was found using an ohm meter. Rather than replace just the one injector, I bit the bullet and replaced all with new Bosch injectors based on my mileage and on the advice I received here on TDR. An expensive decision, but I believe the right one. I wish you luck. - Ed

Replacing them all seems to be the consensus. I bought the truck used with about 195,000 on the clock and I'm now at about 270,000. I have no idea how many miles were on the injectors before I bought it. I'll poke around and see if I can check them through the harness, or if I need to pull the cover. I realize that doing it through the harness will bring the wire resistance into play, but at least I can have an idea if pulling the cover will be necessary.

Thanks, Ed.

 

[Rockranch]

I'm thinking about that, but it is a lot of wiring to hook up, and it's raining. I might try my scangauge II. I think I can get rail pressure on it.

It looks like the Scanguage II won't give me rail pressure, so I guess I'll be reconnecting my TST to monitor the rail pressure.

 

[MMeier]

Sounds like injector time . Get ahold of an IFR thermometer and shoot by the manifold as close to head as you can get , might narrow it down to the faulty one .

 

[Rockranch]

Sounds like injector time . Get ahold of an IFR thermometer and shoot by the manifold as close to head as you can get , might narrow it down to the faulty one .

I have one, so I'll give it a try, though the problem seems to be under load and not at idle. I guess I could talk the wife into hanging on the fender and shooting temps as a drive down the road and get it to knock!

Thanks.

 

[Killgore]

Rockranch, have you found the problem yet? Search the thread "Possible injector problems???". Cerberusiam gives a pretty good overview on what and how to diagnose your issues.

- Ed

 

[Rockranch]

Thanks for the follow up, Ed. To be honest, between the weather and this chest cold, I haven't been able to do more than think about it. I did have a conversation with Mark, over at TST. He was kind enough to give me a few ideas to try, along with the advice I have gotten here.

I'll look into the thread you suggested

Thanks.

 

[cerberusiam]

White smoke indicates unburned fuel, like you get when the injector is spraying well after TDC. The knock and bucking are also indicative of injection problems. Could be one or more injectors hanging open under a load, or, even the FASS failing at high load. Need to monitor pressure at the CP-3 and rail pressure to see what is happening at the time you have the problem.

As a start I would do an injector cleaning and heavy dose the fuel with MMO and 2SO then drive it hard. See if that makes any difference and have the likely answer.

 

[TCDiesel]

At 270K miles replace the Injector(s) (6) and be done with it, all the magic potion in the world won't change the problem other then mask the results.

If you decide to replace them don't believe the advertising hype about special tuned ,balancing, If you buy Virgins or Gen-New Bosch calibrations are in millions of engine problem free.

I could start a housing development in the Death Valley if I promoted that water exist there on the WEB, Handed a few internet cheerleaders a few brownie points to start the Kool-aid drinking and make millions, duping is acceptable on the WEB.

 

[Rockranch]

White smoke indicates unburned fuel, like you get when the injector is spraying well after TDC. The knock and bucking are also indicative of injection problems. Could be one or more injectors hanging open under a load, or, even the FASS failing at high load. Need to monitor pressure at the CP-3 and rail pressure to see what is happening at the time you have the problem.

As a start I would do an injector cleaning and heavy dose the fuel with MMO and 2SO then drive it hard. See if that makes any difference and have the likely answer.

I've tried 2 stroke oil, and some other things, as a diagnostic remedy, but I'm not sure what MMO is. I think my brain just kick on. Marvel
Mystery Oil?

 

[Rockranch]

At 270K miles replace the Injector(s) (6) and be done with it, all the magic potion in the world won't change the problem other then mask the results.

If you decide to replace them don't believe the advertising hype about special tuned ,balancing, If you buy Virgins or Gen-New Bosch calibrations are in millions of engine problem free.

I could start a housing development in the Death Valley if I promoted that water exist there on the WEB, Handed a few internet cheerleaders a few brownie points to start the Kool-aid drinking and make millions, duping is acceptable on the WEB.

Thank you for the suggestions. At this point I'm just trying to diagnose the problem to effect a repair, without throwing parts at it in hopes of getting it right. If I wanted to do that, I'd just take it to the dealer.

The current injectors may, or may not, have 270,000 miles on them. If the problem is actually the injectors, I'll replace them. If it turns out to be a cracked tip, I may just swap out the tips, if the rest of the injector checks out.

I'll check out the website. Thank you.