360 fuel pump knock?

[scooter83]

I just purchased a 69 F100 with a 360 in it. Sounds great cold. Once warm, get an odd knocking/rattling sounds when driving. Running 45-55mph, put load on it and have no noise. let peddle off, have very little noise. Keep peddle just to keep speed, have a knocking sound. I can barely feel it in the pedal. It's coming from driver's side of engine. 10 psi oil pressure idle while warm, 30 psi driving while warm.

The only thing I can hear from a stethescope is a loud knocking noise from the fuel pump. On the engine block I can't hear the noise. Water pump no noise.

The fuel pump looks brand new. Same with the rubber tubing coming into it. I have no idea how old it is. My thought is it's the incorrect fuel pump and the lever? on the fuel pump is knocking. i'm going to attach some pictures. Does this mark on the lever seem normal or abnormal? What about the oily substance on the lever? Is that normal?

[sargentrs]

Sometimes that just happens. Had a similar problem. Used a stick as a a stethoscope and found the same thing as you. No noise at block. Put stick on the top of the fuel pump and there it was. Replaced the fuel pump and no more knock. Maybe a loose pin on the lever? IDK? Just replace it and move on.

[colnago]

That looks like water droplets on the lever, not oil! Here's my long story short with my 352:

The truck ran fine for a long time, then got into this mode where it would just die for no reason. At the time, I didn’t have a PCV valve, just a breather cap. I found milky fluid in the oil, but no signs of a bad head gasket. I would change the oil, only to have fluid again in a couple of days. I finally put a PCV valve on and ran it to the intake. The fluid in the oil disappeared, and my truck stopped dying. I realized that the fluid was "washing the oil" from the fuel pump, so it would stick, and stop pumping. As soon as I added the PCV valve, the vapor that naturally builds in the crankcase was pulled out.

I bet you have the same problem. Your pump is sticking, and finally the spring is able to overcome the friction, so it "snaps" the lever against the eccentric. Bottom line, check your PCV valve.



Joseph

[scooter83]

thanks guys. I've ordered a new fuel pump. I also just pulled my pcv valve and it's disgusting. there was definitely no air moving through there. Trying to find a replacement now. I'll let you know.

I have some type of cap on the valve cover that holds the pcv valve in it. I pulled the cap, then the pcv valve. The cap is disgusting. Where can I get a new one of those?

[scooter83]

Here's a photo. Where can I get one of these and what is it called?

[colnago]

I don't know. Mine didn't have one of those. Maybe you can do without, and just use a PCV valve and grommet.

Joseph

[sargentrs]

Is that your valve cover oil cap or does it just pop into your valve cover like a pcv valve?

[69Ford]

That's a crankcase breather cap you should have two. one on each valve cover. They are removed by twisting them. It also doubles as a oil fill cap. The left one has a hose going to the air cleaner with no obstructions. The right one recieves the pcv valve and goes to the carb spacer. There is a mesh like filter in these caps. I have used a degreaser to clean the filters as long as they are not to rusty. Most auto parts store's sell them after market just make sure you get the twist on type not the push on type. The after market ones do not look stock and you have to change the grommets out with your old ones. Also do not use force to tighten to the valve cover as you will bend the stop tabs in the valve covers and they will just twist for ever. If they are plugged you will not be venting the crankcase causing all sorts of problems.

[colnago]

69Ford,

Does the breather cap serve any particular function? I have a PCV valve on the passenger side, and an oil cap on the driver side. Should either side be enhanced/replaced with this style breather cap?

Joseph

[69Ford]

Here's two pics of what a 69 F100 with the 360 motor should look like. I'm not a big engine guy so anyone who is please chime in. My answer is yes you do need them they vent all the gases and moisture out of your crankcase and also release pressure built up. The PCV valve allows the gases to go one direction to the carb spacer and get reburned during the combustion process so they emit less emissions instead of just going out into the atmosphere. These gases and moisture deteriorate the oil real fast. also I believe you need the one that goes to the air cleaner to let air in to replace the gases exiting as to not create a vacuum. Make sure air can flow through the wire mesh filter inside of them.

My Truck's Engine (5).jpg

Engine Bay (2).JPG

[69Ford]

Shake your PCV valve it should sound like a piece is really loose inside this is normal. If it doesn't sound really loose replace it. Also blow into both sides of it one direction should be free flowing the other direction should seal any air going through. If this test doesn't work replace it. Same principle as a check valve in plumbing.

[BobbyFord]

There's a damper spring above the fuel pump lever inside the housing.
When the spring breaks the pump makes the ticking/knocking sound. It doesn't affect how the pump operates.

[69Ford]

Thanks' BobbyFord I hope the info I gave is correct as I'm still learnin. 69Ford

[Manny]

Here's a photo. Where can I get one of these and what is it called?

Hey scooter they are the pcv breathers. Often just called under breathers. Scott Drake remakes them lil high at 25-30 bucks but they are new and not full of sludge. Checked the link here for them at bronco graveyard.

http://shop.broncograveyard.com/Oil-Cap ... ucts/1761/