Hipshot

Ok, Forgive me for being stupid, but I just bought this thing so I'm still getting used to it. I changed the oil over the weekend, 15-40 Rotella, & installed a mechanical fuel pressure gauge. Took it out for a "run" and played with the turbo a bit . When I got back I noticed a "new" rattle I have not heard before coming from the motor. Like there isn't enough of them already.

Anyway, I tried to analyze this. It sounds like the injector pump rattling on the left side of the motor? However, It could be nothing too. It does sound like its coming from where I ran the copper line thru the rubber grommet in the firewall. But I'm having a hard time believing that the thin copper line could transmit enough noise thru the firewall for me to notice? But then again... it is connected directly to the motor... Ummmm... Any thoughts on this? Am I just being overly concerned or do I need to look into this further?

It does seem to run okay. BTW .. I got 13.5 psi at idle on the fp gauge. 12 psi at cruise, & I couldn't get it under 7 at wot playing with the turbo.. Looks normal to me from what I've been reading here. Okay all you diesel experts.. time to tear up the overly concered newbie! Oh.. and thanks for your help!

Dr. Evil

My first thought is to get rid of the copper tubing - and replace it with flexible air brake line (1/8" with another 1/4" line over top of it for abrasion resistance). There is too much vibration from this engine to use hard line. You do not want diesel pumping into your cab at 15 psi.

The copper tubing is not helping the rattle either. 7 psi at WOT is borderline...when its drops much below this, then its lift pump time.

crobtex

I agree with the Good DR. Get rid of the copper line. Use a rubber or braided hose and put a needle valve in the line at the fuel filter.

Dr. Evil

Yes, without a needle valve or pressure snubber to dampen the pulses from the VP-44 and LP youll kill the guage is a very short time.

Clunk

My 60 inches of grease gun extension lines & fittings and needle valve are available at most favorite auto parts stores...I seal the threads with non-hardening Permatex.

Hipshot

Ok.. I understand the reasons not to use the copper line. Stupid rookie mistakes. That's why I've come to you folks. But do you really think its transmitting enough noise into the cab to be noticeable? And what is normal pressures from a healthy stock lift pump anyway? Thanks!

FozSweet53

If I'm not mistaken a stock LP is internally regulated at 14 psi, my new one runs between 13 and 15.
Foz

Dr. Evil

Reread my post from eariler today.

600 Megawatts

Absolutely it can transmit that much noise. If you listen carefully, you can actually hear the difference in noise in the cab by just ever so slightly pressing on the accelerator pedal and taking up the slack of the throttle cable while you are idleing (I know, there is no throttle, but you know what I mean) . Youre not even moving it enough to raise the RPMs at all, but the taught cable transmits more engine rattle into the cab. Im not crazy, you can hear this, and a few of my friends can hear it on their rigs too. Those pings from a diesel engine are high amplitude spikes and travel great through stiff items.

Another case: On my 6.5 diesel burban, I installed a front axle disconnect device which operates by a pull cable. The pull calbe was leaning on the corner of the cylinder head, and the noise coming up through it into the cab was unbelievable. Moved it so it wasnt touching the engine, and it was fine.

Your copper line has to go, no doubt about that. But please don't run a rubber or plastic fuel line into your cab.... Get an isolator.




KP