Diesel rattle whats normal -- FCA ?

[SDrake]

I started to post this under zzman's thread about how to tell if FCA is bad but thought my post was at least borderline hi jacking.



My truck is the only third gen I have ever been near during operation. I do not know normal. When I got it I noticed a diesel rattle on cold starts as I take off down the road at light throttle still in first and second gear, but of course not as loud as my second gen when cold. About halfmile down the hill I come to a stop at a main highway and enter traffic at normal throttle. The rattle is gone by then. When it rattles it has a cyclic pattern whereby it comes and goes --- one second rattle, one second quiet then one second rattle etc.



My truck has about 110,000k now. Occasionally when hot like after a fuel stop or such it cranks for two or three seconds before starting, one time a bit longer than that. Starts consistantly in about a second or less when cold. Reading the various comments on this site concerning FCA I have thought I need to replace it before getting concerned about injectors. Engine always idles smoothly and responsed appropriately to the throttle. Everytime I get that sluggish hot start I go uh oh injectors.

I am fine with replacing the FCA as general maintainence but have wondered what to expect in the way of the rattle when cold and the occasional prolonged hot start.

Thanks for listening.

 

[Prairie Dog]

My 03 does the exact same things. I'm not sure if it's really louder in the morning than it was when new. If it is then it has come on so slowly that I just didn't notice it. Plus in my case, the Smarty advances the timing a bit and that makes it slightly louder too.
My truck starts exactly like you describe when hot and always has.
I too have a new FCA on the shelf just waiting for the eventual need but I only have 80k miles and it idle's and runs perfectly.

 

[cerberusiam]

Do either of you see any difference in the timing rattle by varying load and rpm's?



The ECU seriously jacks with the timing until IAT and coolant temp are up to operating temps. Advancing the timing just makes it more noticeable. If I run rpms up to 2500 while it is accelerating and the load is up it quits. As soon as the load drops becaus eit has reached speed the rattle comes back.



I have right at 190k with the original FCA and if it doesn't fire by the time you would hit a slow 2 count its unusual.

 

[Prairie Dog]

Yes, very much so. As I drive slowly away from my house I can aggravate it with just the right amount of throttle that it kinda sounds like my old beloved 93 (sniff). A little more or less throttle/RPM and the effect is greatly minimized or gone all together. You probably nailed it (again) Cerb since it seems to be super temp sensitive.

 

[JJPage]

SDrake, sounds just like my 03, even after a new FCA...

 

[SDrake]

I appreciate all the experience testimonials really helps

Thanks guys. And maybe we helped some others. This will help me settle in and just enjoy my truck and not be quite so paranoid with the information about $3000 injector swaps at 100,000k brought on by poor filtering etc. At first I wished I had just gone and bought a gasser.



Having a fuel delivery pressure gauge is nice and I want to get the rail pressure guage so I can learn my truck as I drive. When the torque converter goes I will upgrade transmission and get a smarty

 

[Prairie Dog]

You can read about problems here until you hardly trust it to make a trip to the grocery store. In reality they are very reliable and injector problems are pretty rare.

 

[SDrake]

Agreed and I pretty much have learned a stay the course attitude about this. But the things I read somehow have helped me learn how to maintain my truck. I used the word paranoid with "tongue in cheek. " I have been the only Cummins owner in my world so it is always possible that some noise or behavior is not normal for my truck. This rattle thing had me rattled a bit



Haven't been to a dealer since about 1995 after living through a few nightmares "beyond stupid and simply not believable" with the dealer where I bought a new 1994. I have been a TDR member since 1995. I skipped a year or two in 2003-2004 while away on assignment. That is why you see "Member since 2005" I would never be able to afford this truck if I had to have dealer take care of the thinigs that come up. I also read TDR so as to avoid some of the more expensive repairs such as new injectors prematurely due to poor filtration.



It is diffuicult to explain just how much the kinds of inputs I just received in this thread have helped me so all I can say is thanks knowing that most of you understand how the benefits accrue.

 

[zzman]

I agree, the TDR is my Diesel Bible too.

Thank you one and all.