My truck had a tick when I picked it up. Wasn't too loud, good regular rhythm to it. Could hear it better at the tank than the engine. I was around 14 psi fuel pressure, both at idle and 2500 rpm under zero load. Did the BIC pen spring in the overflow, went to 40 psi. Fast forward a month, and maybe 1500 km, I've got a more metallic tick sound, not a regular rhythm. You can hear it much better in the driver wheel well than anywhere else, although it is louder near the tank. Fuel pressure is still the same. I'm just wondering if this is the tick everyone talks about when their lift pump is gonna take a dump, or if its something else I need to look for. Valves were lashed when I bought the truck, about 2 months ago, just did the timing. All instrumentation still looks like it did before I noticed the ticking noise.

 

I think the tick I told you was normal with mine is the preamble to a dying lift pump. Just recently mine got louder and now I have a high RPM miss/stumble under full load and peak boost is off. I just ordered mine from Freightliner for $115 and the little elbow hose to the heater. Hopefully its here for the weekend, had to come from Surrey.

I will be checking fuel pressure tomorrow after some slight mods to the fuel system for some Swagelok fittings.

 

Thats a good price. I picked one up when I bought the truck when I had that initial quiet tick. Paid about $20 more than you. Still no stumble or anything of that nature, but I can't really wind it out. Clutch will only hold till about 25 psi at best.

 

25 psi isn't much. That clutch is toast I would say. I only ever slipped my stocker with the plate full forward over 35 psi..

 

Update..
Threw in the new transfer pump, new hoses to the OEM lines and filter. Holy smokes, what a difference! Idle is up, idles smoother and if you thought my AFC needed tinkering before....Well, I can't keep the smoke down anymore. Impressive too is that the throttle response is back. Lately it would be a little laggy under very light accell to get going.. Unfortunately I didn't get before and after fuel pressures.. I didn't have the correct fittings.

Oh and I have to do some more tests, but that tick is mostly gone. If I grab the return line now, its more of a buzz than a pulsing.

 

Hmm, maybe I'll have to add the lift pump to the To-Do list. I noticed today that as I bring the rpm up, it gets more frequent, but at 1000 rpm is completely disappears. After the clutch, I'll probably do that before I throw the GSK in.

 

My lift pump only ticked on cold winter days. Cold for me is -20°F. I let ig go.
After a couple years the ticking started at higher and higher temps. I finally replaced it last winter when it ticked at +20°F.
New pump doesn't tick down to -30°

Remember a ticking pump will wear on the cam lobe. Don't let it go too long. A new overflow vlave is also cheap.

 

Check your fuel filter.

And really hammer on it - do you get white smoke?

Sounds like a gas stove trying to light?

Same thing happened on mine - turns out the filter was plugged (This was when I first purchased the truck)

Lift pump has been fine ever since.

 

My fuel filters are clean and the last one I put in was at the last oil change. Without pressures, I can't prove that the filter wasn't the cause, but the changes in performance and overall running of the engine are telling me different.

 

I have a used LP if you want to try it...I replaced mine, in the time I was trying to find out why my truck was shutting down.Mine still ticks even with the new LP and OF....But I haven't changed my fuel filter in almost a year either...

 

Filter was changed just after I bought the truck. Cleaned the pre-filter at that point as well. I did run a couple jugs of bio through it, so it might have cleaned out the fuel system a bit. I have another filter kicking around, I might pull the old filter out and see how it looks.

No white smoke, just nice black smoke.

I just noticed the noise after I timed it, but I'm guessing thats coincidental.

Dave, thanks for the offer, but I've got a brand new one sitting on the shelf right now.