Is Your Engine Sound Consistant...?

[HammerDown]

Some days I notice my engine sounds tight and right, can't even feel idle vibrations and almost like there's a thick bed-comforter over it = 'goooood feeling'

Then, maybe later that same day or maybe the next day or so, the idle isn't as buttery-smooth, it sounds like a BBC in need of a valve adjustment and a old coffee-can full of nuts & bolts rattling around > this makes me craz-ier then usual

 

[rjglenn]

How my truck sounds is very temperature dependent. On cold days (yes, we have the occasional cold days here) it runs great, plenty of power but it is noisy. In the middle of summer when it's 95* it's quite but I don't think it would get out of it's own way.

 

[Black dawg]

Not much to go off of, but betting crappy injectors or sticky advance.

 

[IDIDieselJohn]

X2 on sticking timing advance.

 

[Wyreth]

X3 on sticky advance.

I had that happen to me. Same symptoms. Did not understand what was going on until I got my j3300 hooked up to it, and watched what was happening. Lucky for me, I did the ATF in filter, then let it sit overnight. Took alot of treatments, about a weeks worth, but it came loose. So I would say try it a few times. It's certainly not going to hurt anything.

 

[HammerDown]

Interesting feedback about "sticking advance"...as I've noticed this since I installed the Baby Moose.
Could someone explain what cause the advance to stick...is it gummed-up or tight tolerances, would it be scar damaged?
How to treat it or is the damage done???

 

[Black dawg]

How many miles have you put on the pump?

 

[Dieselcrawler]

Mel replaces the advance pistion, so scarring is probly not an issue. Check the linkage on the driverside of the pump, see if it moves freely with throttle movement.

 

[SLC97SR5]

I have had this same issue since installing my Moose Pump.

 

[HammerDown]

How many miles have you put on the pump?

Difficult to say for sure...in my house sick and paperwork would be in the truck but...I'm doubting 3000. Don't even think I put 1000 a year anymore.

Can someone tell me how to do the ATF fluid treatment?

 

[Black dawg]

Difficult to say for sure...in my house sick and paperwork would be in the truck but...I'm doubting 3000. Don't even think I put 1000 a year anymore.

Can someone tell me how to do the ATF fluid treatment?

I dont think I would bother with the atf trick. Just heavily dose it with some fuel additive and drive it. When you drive it, is it short distances?
My trucks start behaving badly if they dont get a good workout every so often.

Seems like I remember you commenting on a rough idle. Have a way to test the injectors?

 

[Wyreth]

Interesting feedback about "sticking advance"...as I've noticed this since I installed the Baby Moose.
Could someone explain what cause the advance to stick...is it gummed-up or tight tolerances, would it be scar damaged?
How to treat it or is the damage done???

That said, the very first thing I would do, is call Mel and ask him about it. He knows these pumps. More than that, he knows EVERYTHING about his pumps.

Call him. He stands behind his pumps and will have your answers.

 

[HammerDown]

I dont think I would bother with the atf trick. Just heavily dose it with some fuel additive and drive it. When you drive it, is it short distances?
My trucks start behaving badly if they dont get a good workout every so often.

Seems like I remember you commenting on a rough idle. Have a way to test the injectors?

In my area driving is all local stop & go, the RPM never gets above 1800 and usually just 1500 with a light pedal around town. I rarely if ever get on the interstate (I-95) anymore.
I've been pretty diligent about using TCW3 one oz-per gallon, then I may skip a treatment.
I originally tested the BB's prior to installing and they all showed a nice 'cone pattern' and popped very close to the same psi. I borrowed the tester...that friend moved far away.

One thing I do notice that seems to help...when it starts to have that "limp mode" sound, I'll really lay into the throttle making the shift points up around 2800 and it seems to be better for a day or so...does this sound like the 'advance piston' sticking?

 

[Black dawg]

Without hearing it run, or putting a meter to it to prove timing change, hard to say for sure.

At this point I would look at the injectors, especially if they are the delphi bb codes. When I replace a set, very rarely do I not have a couple that have issues in the first 5-10k. Most of the time a good hotrodding on the tester will straighten them out.

hot rodding the truck can straighten out the injectors especially if you have a high fuel rate.

 

[SparkandFire]

I am of the opinion that the fuel we are supplied for around $4 a gallon is more or less crap these days.

The cetane index of fuel in this country is allowed to be as low as 40, whereas Europe requires a minimum of 50. The higher the number the better the fuel burns and the higher cetane fuel burns better in high speed engines (such as ours)

Cetane is basically a measure of how fast fuel burns. You figure most mid to long range diesel engines are designed to run closer to 1800 RPM. Our engines can run up to 3200 RPM.

There is ZERO incentive for the fuel suppliers to provide higher cetane fuel. It costs them more money. My guess is that if you took an average sample of the fuel from, say, ten stations and compared them, you would probably see the cetane somewhere close to 40 - 42 average.

We deal with this on a regular basis in my industry. We have close to 60 megawatts of diesel generators to power the datacenter if we loose utility power. If we buy a diesel generator that is spec'd to provide 3 megawatts of power at cetane 45, and we get 40 cetane fuel, our genset may only provide 2.85 MW of power when needed. We actually require our fuel suppliers to provide fuel quality reports when the fuel is delivered, and we require greater than 45 cetane fuel...

All of this rambling leads me to one theory on why our engines run differently at different times. All things being equal and functional, everything that affects timing on our pumps is static (except fuel pressure) The advance cam, lever, and piston (if in good shape) operate the same way every time we push the GO pedal down. The two things that are dynamic in this system are;

A) Fuel pressure
B) Fuel quality

Of course the mechanical lift pump on our trucks has much more variance potential than an electric pump would (as it's pumping speed is directly proportional to engine speed) But again, the pump curve (volume and pressure) of even a mechanical pump would be somewhat linear to engine speed. So that really only leaves fuel quality. It's the one variable that we really don't have any way of accounting for...