Txwelder

I have described the ticking in the past as a bad lifter in a Gas V8. That is as good as I can describe it. No ticking at idle, other than my normal 12V noises, then under a load with RPM it ticks real good, like a bad lifter. I replaced the exhaust this weekend with 5" straight pipe, which I love, but the ticking is still there. My next move will be to check all push rods, if none bent then change the fuel filter. If that doesnt do it then I will drop the tranny and check for a cracked flexplate. If no cracked flexplate then replace lift pump. I will just have to eliminate one at a time until I find it.

ratsun

Hummm.... I really thought it would have been your exhaust
I still dont think its a tappet or push rod though.
Hope you nail it down soon

Txwelder

Yeah me too, really getting to me. Ive posted about this before and mostly got exhaust or flexplate responses. We will see.

Txwelder

I started the truck with the valve covers off and didnt notice anything out of the ordinary, well, as compared to the rest of the valves, they could all be messed up and I wouldnt know. I looked, listened, felt, smelled and tasted, nothing looked abnormal. If I remember correctly, when I changed my lift pump, I could see a wear mark on the rod that contacts the cam. Would that be there on a lift pump that was functioning properly? Just wondering if I can pull it out and look to see if there is any excessive wear on the rod and if that is an indicator of the pump going south? How much is involved with installing a fuel pressure gauge on a 12V? Is it even worth it? So now I am down to it being the lift pump/fuel filter or a cracked flexplate.

TIMMY22

any of the lift pumps that I have changed had no wear on the plunger rod.

Txwelder

The one I changed had a visible wear spot where the rod was slapping the cam. It wasnt centered either, it was off to one side. Im just curious if pulling it would be a waste of time?

Baja

Pulling the lift pump is easy, putting it back in is the work. If you do decide to pull it, toss out the bolts and replace them with studs and nuts. Before you go through the hassle, take a rubber hose and put one end on the lift pump, the other to your ear. If the pump is ticking, you will hear it loud and clear. A metal rod will work too.

Txwelder

I did the stethascope thing with some garden hose and cannot narrow any of it down. It only makes noise under a load, in gear, while driving. So if any of this info rules out my lift pump let me know. I know when my last lift pump went out it started ticking at idle and would only get faster with RPM. This pump is not ticking at idle, something deffinately is though. So I am leaning more and more to thinking that the flexplate may be the problem. I can get an SFI 29.1 approved flexplate here in town for $99 that is .035 over stock, just takes them 10 days to get it in. Wonder if for that price I should just replace it and see what happens?

Txwelder

I dont know if its in my head but I think I am starting to feel this in the floorboard and the throttle.

Baja

Do you have a fuel pressure gauge? If so, what are the readings? If not consider hooking one up, even as a temporary.

Txwelder

I just cant see a lift pump making that much vibration through the entire truck. Maybe that is my ignorance of the power of that pump, but it seems to me that it would be something bigger with more ability to vibrate the truck.

plow

no luck yet txwelder?

Txwelder

Well not really, Im at work today and will change the oil/filter and fuel/water separator to see if anything gives there. After that, then really the only other thing I can think to do is to drop the tranny, I know I keep saying that, its just alot of work and nobody to help me right now. I will probably go ahead and replace the flexplate while I am there anyhow, then if that doesnt do it then I guess the lift pump. Then if nothing I will trade it in on a new one.

Txwelder

Fuel filter did nothing.

Baja

After all of this, realize that you are not alone. If it is the lift pump, mine ticks too. I don't hear it at idle, but I do under load or as the RPM's start to climb, and it can get pretty loud, but I do not have the vibration you mention. For me, I am all but certain that it is the lift pump, there is nothing else down there. I have a 5sp, so that rules out the flexplate. I have a fuel pressure gauge and it is holding good pressure, so I don't worry about it, but I do watch it. This is my second lift pump, but I got it used. Unfortunately you can't rebuild them, only replace them.