Injector Rattle?

[CTcummins24V]

Do the 24Vs have injector rattle? And under what circumstances does it occur? I'm getting a really loud pinging and panging, like a metal on metal sound, in low rpms when on the throttle. It happens from 3rd to the 3rd lock-up and 3rd to 4th. Right after the shift, the rpms drop to 1300 or 1400 and it starts pinging, but as soon as I get past 1600 or so rpm I don't hear it anymore. My fear is pistons hitting the valves, and NO, I haven't done valve lash yet. Any ideas?

[Ilikeoldfords]

Did it just start making the noise? Mine will kind of ping if it is cold. Usually goes pretty much away when warmed up. I think that if the pistons were hitting the valves it probably wouldnt run very good. Just my opinion though.

[joecool911]

I thought that may be mine too. But listening to other 24 valve trucks and recent change of injectors has made no difference. Are you running 2 cycle oil? That helps. That high idle mod would also help in economy setting. Retards the timing. But this all assumes there is nothing wrong. Listen to other trucks. I think the VP makes noise too.

[MnTom]

Does your Edge have timing settings? Timing is what would give you a rattle. If your valves were hitting your pistons you would not be able to start your truck let alone run it.

[CTcummins24V]

I just read an article on a 6.4 powerstroke that was making valve/piston contact at low rpms with higher power and I got spooked. Yes I'm running 2 cycle. Comp is set at 5x3, most timing and fuel at setting 5 but not till 10lbs of boost? The pinging only happens when I'm on the throttle a good amount under 1600 rpms. If I accelerate normally under 1600 rpms it doesn't make the pinging sound. Fuel/pressure related?

[mulcher812]

Ct how many miles do u have on those injectors? I have seen some with worn out injectors that will rattle.

[CTcummins24V]

Less than 20k, I just put them in last year. Idle and everything else is smooth and good.

[mulcher812]

I know it might sound like a lot but you may want to pull them and have them pop tested. I've heard them rattle and ping but they were worn out when they did it. And I mean worn out.

[Mopar1973Man]

Do the 24Vs have injector rattle? And under what circumstances does it occur?

 

Yes. When the timing is over advanced from

 

* Cold Air - The colder the IAT temperature the more and more timing is advanced.

* Cold Coolant - The colder the coolant temperature the more pronounced timing advancement.

* Low to Zero Boost - Low to zero boost will advance the most.

 

http://en.wikipedia.org/wiki/Autoignition_temperature

The autoignition temperature or kindling point of a substance is the lowest temperature at which it will spontaneously ignite in a normal atmosphere without an external source of ignition, such as a flame or spark. This temperature is required to supply the activation energy needed for combustion. The temperature at which a chemical will ignite decreases as the pressure or oxygen concentration increases (increased boost pressure). It is usually applied to a combustible fuel mixture.

 

 

So with more boost pressure there is more retarding of timing.

 

Yes. Wore out injectors with excessive low pop pressure will fire early causing injector rattle too.

[CTcummins24V]

Over advanced timing=greater pressure change? Greater pressure=injector rattle? Turbo doesn't light till about 1600 rpm or so, therefore little or no boost, with the advanced timing from the Comp=injector rattle. I'll have to run the truck with the Comp off and see if it still abnormally pings. Thanks guys and Michael! I'll report back later!  

[mulcher812]

Make sure you unplug the pump tap wire just in case the comp is doing something weird internally.

[Mopar1973Man]

Make sure you unplug the pump tap wire just in case the comp is doing something weird internally.

 

More so the CANBUS connector but for test purpose I would pull both CANBUS and wire tap.

[mulcher812]

Yeah totally forgot about the CANBUS

[joecool911]

I am wondering also about the air intake sensor, if that goes bad will the timing be more advanced all the time question. And cause excessive engine ticking?

Edited May 13, 2014 by joecool911

[Mopar1973Man]

That why I suggest testing with a live data tool first to verify the IAT is actually damaged. Only about 1% of all the IAT actually fail. Even with my exhaust brake and all carbon/oiled up mine is still correct so the old wife's tale washing off the sensor isn't true. Also with my IAT now fooled solid at 143*F no codes and no MPG's issues either.

 

The two big players in timing is ECT, IAT and Battery temp sensor. Yes. The battery temp sensor does play a role in it too.

[CTcummins24V]

Took the old gal out for a drive today, turned the comp off, and she didn't rattle at lows rpms. Turned the comp back on and she rattled. Only tested a couple times but it appears Michael is correct again. Hopefully this week i'll do some highway driving and retest a couple more times just to make sure it's the combination of low boost and over advanced timing that's giving me injector rattle. 

[TFaoro]

I think a lot of trucks rattle like that with a comp. To me it sounds like there is a big change in timing causing the rattle, then when the boost comes on the rattle goes away

[Mopar1973Man]

I think a lot of trucks rattle like that with a comp. To me it sounds like there is a big change in timing causing the rattle, then when the boost comes on the rattle goes away

 

That rattle is caused by any performance module. But as boost rises the timing should retard which it does typically. Also the colder the air is the worse the problem gets so warming the air reduces the timing rattle and does produce better MPG for daily driver.

[TFaoro]

That rattle is caused by any performance module. But as boost rises the timing should retard which it does typically. Also the colder the air is the worse the problem gets so warming the air reduces the timing rattle and does produce better MPG for daily driver.

I'm not sure if all of them do it... My smarty with timing maxed out doesn't rattle at all.

As for temperature with the comp, I have ED's high idle, so IAT is at 143 at all times. A colder motor does make the rattle worse, but it is still noticeable at 190 deg.

Now the battery temperature.... what is the purpose of this? I do notice my alternator charges at a higher voltage when it's colder??? Does this directly affect the timing of the engine as well? 

[Mopar1973Man]

I found a article a while back that explains a weird behavior of the IAT sensor. Say for example the IAT is forced 143*F, the coolant is actually 195*F and the outside temperature is <60*F you go start the Wait To Start doesn't give any grid heat pre-starting but post-starting there is grid heat. But now if the outside temperature rises to 100*F now there is neither pre-start grid heat or post-start grid heat. The only sensor left on the truck that can sense temperature is battery temp sensor. 

 

So the best I can say is the PCM communicates this information to the ECM over the CCD network.

 

Battery temp sensor is designed for controlling charging voltage vs. temperature. But the article I did find the system will use some of the information from the battery temp sensor when and what I'm not sure exactly.