Lots of hammering ...lift pump??

[JJW_ND]

Each winter when temps go below zero I have to get reaccustomed to the tick or slight hammer sound comming from injections pump side of engine.



This winter it is getting really bad. Engine has 210K on it. Just changed overflow valve (first time) a few months back with one from Piers. I have never seen any leaks around lift pump. Everything runs/ starts fine.



Just makes allot of hammering sound when putting under a load (25+ boost and 40' of trailers). Mellows to a tick when running empty on flat ground. Definitely worse with cold temps (below zero lately).



I had fuel pressure checked and it was 18 at idle and about 28 WOT. I think this is OK.



Everthing tells me the lift pump should be just fine.



Do they ever get noisy and still pump in spec?



Im guessing the older overflow valve kept the pressures down which kept the ticking/hammering down. Now with a fresh overflow and getting tired lift pump the noise is pretty bad.



Will a new lift pump make the noise go away? or just cause me to have a perfectly good backup lift pump that I don't really need.



I wish it would just become summer..... all the noises seem to go away with warm temps.



jjw

ND

 

[illflem]

JW, my fuel pressure normally runs about 26 at WOT, but at temps below about 15° it will run almost 10 psi higher for at least an hour until my tank of straight #2 warms. I've never noticed ticking but it seems that the thicker fuel would be harder to pump and also cause the rise in pressure. Perhaps the cam lever in your transfer pump isn't returning fully due to thicker fuel and the tick you hear is it tapping on the cam. I've always heard that if you hear ticking from the pump it should be replaced or it can damage the cam. Could it be your lift pump cam lever return spring is slowly dieing or your fuel heater isn't working? If the ticking mellows after the tank fuel warms up I'd say the lift pump is going.

 

[JJW_ND]

Thats kinda what I thought Bill. I like you run #2 year round. Even with additives it must be pretty THICK!



Today temps in 20s and noise is much reduced.



I just hate to replace perfectly good working parts. I have no problem replacing something that still works but is just about to fail.



I think I will get a new pump and put it in.



With 200K on the original and lots of winter (think fuel) operation it has serve me well.



jjw