Knocking and gray/white smoke

[cerberusiam]

2SO is good for lubrication, not so good for cleaning. You will need a solvent type additive to clean and accumulation of asphaltenes and other stuff common to ULSD. A quart of Sea Foam and a quart of MMO is a really cheap effective way to see IF you need to dig deeper. Since the problem is intermittent and not constant plus the lack of codes, that would suggest a mechanical issue with the injector. The cleaning and extra lube will cure the problem but it might alleviate it enough to tell that the problem is mechanical and where it likely is. Along wit the cleaning you really need to see if RP and LP pressures are not doing any thing weird when the glitch happens.

However, at 270k miles or a significant fraction of that mileage it is a good bet the injectors are wore and failing. If you could get the dealer to run a contribution, kill test with rpm drop, and a return flow test on the injectors that would probably tell you a lot. If they will, too many times they won't do the test just want $300-400 to pull the injectors and send out for testing and you have no control on what is going on.

 

[Rockranch]

2SO is good for lubrication, not so good for cleaning. You will need a solvent type additive to clean and accumulation of asphaltenes and other stuff common to ULSD. A quart of Sea Foam and a quart of MMO is a really cheap effective way to see IF you need to dig deeper. Since the problem is intermittent and not constant plus the lack of codes, that would suggest a mechanical issue with the injector. The cleaning and extra lube will cure the problem but it might alleviate it enough to tell that the problem is mechanical and where it likely is. Along wit the cleaning you really need to see if RP and LP pressures are not doing any thing weird when the glitch happens.

However, at 270k miles or a significant fraction of that mileage it is a good bet the injectors are wore and failing. If you could get the dealer to run a contribution, kill test with rpm drop, and a return flow test on the injectors that would probably tell you a lot. If they will, too many times they won't do the test just want $300-400 to pull the injectors and send out for testing and you have no control on what is going on.

I have asked the dealer, in the past, about a contribution test, and was told it's not available for the 2003.

I expect what I'll do next is reconnect the TST so I can monitor rail pressure and look at connecting a fuel pressure gauge for the low side. I'll also pull the valve cover and ohm test the injectors. If that doesn't show anything, I'll pull the injectors and look for a cracked tip.

 

[cerberusiam]

WiTech probably does not support that year, should but Corp is really screwing with what they can do and some dealers simply don't know how to use the equipment. A return test can be and that would help diagnose.

A cracked tip would show symptoms all the time. A bad solenoid will almost always throw codes and shut down the bank if it is bad enough. However, they can intermit and still not code. Get it warm first before testing solenoids, they usually don't show failure cold.

Trying to change tips on a CR injector with the right tools and knowledge is dangerous, it has to be done correctly or the problems can get worse. If there is any damage your best option is a new set.

 

[Rockranch]

WiTech probably doe snot support that year, should but Corp is really screwing with what they can do and some dealers simply don't know how to use the equipment. A return test can be and that would help diagnose.

A cracked tip would show symptoms all the time. A bad solenoid will almost always throw codes and shut down the bank if it is bad enough. However, they can intermit and still not code. Get it warm first before testing solenoids, they usually don't show failure cold.

Trying to change tips on a CR injector with the right tools and knowledge is dangerous, it has to be done correctly or the problems can get worse. If there is any damage your best option is a new set.

Thank you.

Mark, over at TST, suggested a possible small crack in the tip, that grows under increased pressure, causing the intermittent knock/smoke that goes away under cruise. That makes sense to me. When I have the time, I'll dig into it and figure out what is actually wrong and fix it.

I appreciate everyone's input on this.