Cat diesel smoking after New injectors

I recently had new injectors installed on my 3160 Cat engine that did not smoke much at all on cold start-up, but now I am embarrassed at the dock due to the amount of light blue/white smoke I am sharing with any unsuspecting boater downwind of me. This condition subsides when the engine gets warm. I and my expensive mechanic can't figure out why older injectors would do fine and New ones don't. Any thoughts or suggestions would be appreciated.
3160 Caterpillar, 940 hours on rebuild, fresh diesel in December, new filters and conditioner for winter.

Did you test the new injectors before installing? I've seen brand new ones that were leakers right out of the bag. Now I always have the shop test new ones. It was a hard lesson to learn.

Also, are you sure that they are the right injectors?

Just curious, to why you replace them?

Why did you replace the injectors? Are the old ones still around? Replace them and see what happens. Are you sure the expensive mechanic didn't play around with the pump or do something else to "help" you? Boatdiesel.com is your friend.

I would suspect your mechanic tweaked the pump timing. That makes a huge difference in the amount of smoke.

Jon, have some gear lash at my velvet drive so he wanted to make sure I had equal pressures in each cylinder. When he sent my old injectors in for testing he was told to just replace them, so he did. Unfortunately the injectors and rack are under the valve covers on a 3160 so he had to put it all back together without testing individual injectors. Aanned I still have gear lash. :-(

I would make sure that the injector/nozzles are the right ones.

I will have him look at the timing again, I know he mentioned not being able to see timing marks when he was working on the injectors. Don't really know what he was or was not seeing.

Bob Hudspeth said:

Jon, have some gear lash at my velvet drive so he wanted to make sure I had equal pressures in each cylinder. When he sent my old injectors in for testing he was told to just replace them, so he did. Unfortunately the injectors and rack are under the valve covers on a 3160 so he had to put it all back together without testing individual injectors. Aanned I still have gear lash. :-(

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So, you're saying that he fixed no problem and created problems that didn't previously exist? I don't think the suggestion was testing them installed but testing them first in the shop like the old ones were tested. And now he can't figure it out? You paid him as an expert. I'm definitely not getting a good feeling about your mechanic's skills.

Rebel112r said:

I would make sure that the injector/nozzles are the right ones.

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We had our injectors rebuilt and they installed the wrong tips on 3 of the 6. The tech never tested after the rebuild even though the paper work said he did. The rebuild shop paid for the rental car, gas and a new valve cover gasket.

Bob Hudspeth said:

Jon, have some gear lash at my velvet drive so he wanted to make sure I had equal pressures in each cylinder. When he sent my old injectors in for testing he was told to just replace them, so he did. Unfortunately the injectors and rack are under the valve covers on a 3160 so he had to put it all back together without testing individual injectors. Aanned I still have gear lash. :-(

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I have 3208TA's on board so I totally understand the issue of where the injectors are. It's not an easy job to just pull them out.

As for pump timing I'm pretty sure the 3160 injection pump timing can not be changed. I know it's pump different than the 3208 but from memory it's pretty much a straightforward setup. Put the pin in the front of the engine and line everything up. The timing advance mechanism is built into the pump drive gear and cannot be changed.

Just an observation but I think the mechanic owes you a replacement job on his dime. I might offer to buy the gaskets but the labor should be on him.

As for gear lash, are you speaking of gear rattle? If so and you have the old style plate setup and not rubber dogs then it could be the cause of your rattle. If it has rubber dogs the rubber does go bad and it too can then rattle.

We stuck a couple of nozzles, I think were for a 3208, into a 3160 powered Ford dump truck. Needed to get it running and they fit, so they were used. They were spares for a fork mounted snowblower, seemed to work fine. If we would have changed all 8 we may have had issues. Fuel delivery from pump would have been same, but internals of nozzle definitely not the same.

Bob Hudspeth said:

Jon, have some gear lash at my velvet drive so he wanted to make sure I had equal pressures in each cylinder. When he sent my old injectors in for testing he was told to just replace them, so he did. Unfortunately the injectors and rack are under the valve covers on a 3160 so he had to put it all back together without testing individual injectors. Aanned I still have gear lash. :-(

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Injectors and gear lash have nothing to do with one or the other. If at idle in neutral you have a rattle and it goes away in gear the idle is to slow or the springs in the drive plate are wore out. If the idle rpm is at spec it's the drive plate that needs replacing.


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Bob Hudspeth said:

I will have him look at the timing again, I know he mentioned not being able to see timing marks when he was working on the injectors. Don't really know what he was or was not seeing.

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All the cats I ever worked on used a pin and a bolt to set timing, if your mech was looking for timing marks you need to look for another mechanic.


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The gear rattle/lash is happens while in gear from idle to about 850 rpm, absolutely quiet and smooth above there. I do not know for sure what he meant by saying he "could not find timing marks" I will have to ask him about the pin and bolt. Would being off a little cause cold start smoke but quickly clean up when engine is warm?

Two kinds of gear rattle: One is normal where the engine speed varies with the firing pulses, four events per rev. The pulses smooth out with added revs and the noise goes away. Can be worse if torsional coupling, aka drive plate is worn out. But some noise can be completely normal.

The second type of gear rattle is where a cylinder misfires. This sounds like a "clank" every two revs, much slower than the first type of noise.

You can test this by one at a time loosening a fuel line nut. Listen for change in sound. And change in smoke.

So you need to find out if the noise is four per rev or one per every two revs.

Regarding the smoke, if you put engine in gear at idle, does the smoke quit?

Changing injectors does not involve anything that changes injection pump timing, so unless he fiddled with something, timing should be the same as it was.

Did he set valve lash correctly? Screw that up and it could cause smoke. Valve lash has to be set after injectors since rocker shaft has to come out.

Where did the nozzles come from? Some counterfeit crap parts floating around in the injection world.

In our out of gear does not matter. The rattle/ grinding rock noise is isolated to the the V drive not the engine. We were thinking flex plate all the way but the injectors, and cylinder compression were suspected to be causing some of the issues so he changed the injectors and checked compression to rule out those causes. He did mention valve lash adjustment so I will bring that up to him. As far as the injectors are concerned I have no idea where he got them, but his company is a reputable service provider in downtown Seattle.

Is the gear rattle a new thing? So was it quiet before?

I sure hope this isn't your issue, but some mechanics are simply a buy and replace with nothing toward proper troubleshooting. I tell my mechanics that when they tell me XYZ is wrong and they state this will fix it, I have them put it in writing. Then I tell them that if their fix does not fix it all future parts and labor are on them, not me.


In some cases they call in a "more expert" to make sure proper troubleshooting is done.

The rattle/gear lash is not new, I believe it happened due to a hard reverse shift by me when a sailboat left a fuel dock without seeing us, putting his bow sprit into mine before I got out of his way. I think he forgot he was not under sail, or he dined and dashed after feeding his fuel tank. Now I wish I had gotten his registration numbers. This leads me to believe I damaged the flex plate with the shift and quick power up.

In over 50 years on the water, I have been towed twice and damper plates were the problem both times. Change that plate b/4 you are left dead in the water.
While you are at it get a plate w/o springs and a "get home" feature.

That looks like what I expect to find. Was your issue a catastrophic failure or did you know you had a problem?

"

"All the cats I ever worked on used a pin and a bolt to set timing, if your mech was looking for timing marks you need to look for another mechanic."

IF the "mechanic" does not bring Da Book for your specific engine when coming aboard ,

turn him back IMMEDIATELY!!!!