As promised, here are my numbers after changing from the gray CPS back to the black CPS. (It has been a while since I promised these).

Gray CPS: Black CPS:

Cyl 1: 0-.5% .6-1%

Cyl 2: 0% 0%

Cyl 3: 4.9-5.5% 3.0%

Cyl 4: .1-1.1% .2-1.1%

Cyl 5: 0% .5-.7%

Cyl 6: 0% 0%

Cyl 7: 0% .3%

Cyl 8: 1-1.6% 0%

Here is my question to you guys; I still have an intermittent knock in the motor when it is either warm or cold.

Last conversation I was going to look at injectors. I was told to change back to the black CPS first. Where do I start to look now?

 

No one has a place for me to look?

FT

 

#3 still seems a tad high, but is withing acceptable limits. I guess you're not tripping any contribution faults on a CCT?

How bad is the knock? Have you tried swapping to a different brand motor oil? These engines seem to behave a little different with other oils. Overall the numbers do look better. Did you notice a little smoother idle with the black CPS?

 

Chris, Sometimes is sounds like the rod is about to come out the block! Then the next time I run it...you do not hear it at all. I do not really hear it while running down the road...even at 25 mph. Mostly at idle.

You are correct; no codes. I have not tried a different oil. I may try that next. I did notice a much smoother idle after the black CPS swap. Starts a little quicker also.

FT

 

Chris, One more thing; a friend of mine has an injector isolator box made up to shut off individual injectors. I thought about trying that to see if the knock goes away if one injector is shut down.

What you think?

FT

 

Try a different oil on the next change and just keep an eye on the rotational velocity readings. I've got one injector that knocks a little at low RPM with Delo oil, but has no other issues and tests out fine.

It's just one of those things. Kind of like how you don't notice the rougher idle or slower starts when the gray CPS is put in, but you do notice the improvement when you switch back to black

 

This is the exact same knock that I've had on my truck for 2 years now. On my truck it's either the #2 or the #4 cylinder. However, my truck continues to pass every test I throw at it, so the injector is still functioning properly. I've also heard quite a few other PSD's with the exact same knock. So this isn't an isolated incident.

As for what causes it, there could be a slight issue with the injector internally that causes it to knock, or maybe you need to re-torque the injector hold-down bolts. Overall I haven't been too concerned with it knocking in my truck, so I haven't done anything to rectify it just yet. Sometime in the next few months I plan to swap out the glow plugs, and at that time I'll re-torque everything under the valve covers and see if that helps.

Yes this will help you identify which injector is the culprit.

 

Thanks Pocket...I will try the isolator and see which one it could be.

BTW... How is that snow? I heard you guys were supposed to get 14" over the weekend. I am an x Coloradoan myself (SE Aurora).

FT

 

I saw 2 feet of snow at my house, so yeah that was a fun weekend of plowing and shovelling. Felt like January instead of April

But at least it's melting fast. I just put fertilizer down on my lawn a few days before the storm hit. My grass is going to be super green in about 2 weeks.