OK, after reading on here I think I was stupid.

In the process of replacing the rusted oil pan on my 351w I decided to change the oil pump. So when I bolted the new pickup tube to it I used the gasket but also a tiny little bit of RTV silicone. I'm fairly sure this didn't squeeze out much at all. Should I take it back apart and clean the silicone out of it? I used a tiny bit because I was worried about having scratched the mating surface on the pickup tube and having the pump suck air (I was very careful not to scratch but I'm paranoid I did). There cannot be more than a paper fine amount of silicone that got pushed out, can this really lock my pump up if it lets loose? The bead I ran was finer than a pencil lead.

How about where the pump bolts to the block. The factory pump did not have a gasket there. The surfaces look like they're precision milled and should seal good enough without a gasket. Is there supposed to be a gasket there and how critical is it? I was thinking there wasn't one there so the bolts could be torqued for a more positive joint. If there's a tiny leak there it's on the pressure side of the pump anyway.

I have not put the pan back on since I am having a miserable time with the gasket from Napa. No matter, I have ordered one from the Ford dealer. But getting your arm in there to get the pump out and back in is just a rotten time, especially if you don't want to take the distributor out and you're lining up the shaft with the bottom of the distributor.

 

I don't think you will have a problem...I can't imagine silicone locking the oil pump up. What I can see is a little bit of the silicone breaking free and getting stuck in the oil pump relief valve, which means you would not be able to build oil pressure. I can say that will experience. You can get oil pan gaskets (rubber) with steel inserts that keep the gasket from being over tightened and allow a good seal. Your call...if the silicone was a thin bead and has had a long time to cure before being used, I don't think you would have a problem, that stuff is pretty strong...however...your the one that is takig the gamble not me. Good luck

 

Okay, I completely took the thing apart and spent an hour and cleaned every tiny spec of silicone or anything else out. I primed the pump well and put everything back together just as clean as a whistle. Everything's OK there.

Then when I was jacking the motor to take the wood out from between the motor mounts and the crossmember, I pushed up the bottom of the oil pan a little bit (I used a 2x4 between the jack and the oil pan). It's creased up no more than maybe 1/8" or so, toward the front of the rear hump.

Question is, how far off the bottom of the pan does the pickup sit? I think I remember it being toward the rear of the hump anyway, right?

I can't remember and I saw it apart three times too....

I'm going to crank it over with the starter here in a couple of days and watch for oil in the valve covers, and then start it up and see where the oil pressure is, but I thought I'd ask to see if I should even do that or if I need to work the oil pan back down...

BTW, the Ford gasket is worth the money. I bought whatever Napa had, usually they have better parts, but this had no stiffness and no dowels and I could not get it to stay in place and seat in the timing cover and #5 bearing cap grooves at all. I was able to actually get the Ford gasket up on the bottom of the block, stuck there by the four corners, enough to get the pan up perfectly. The Ford gasket cost maybe $3 or $4 more. And it's stiff on the sides so it won't squeeze out from between the block and the pan. I've heard the Fel-Pro is good too though, didn't try that one.

 

YOu might wanna double check your pickup tube to oil pan clearance.

 

Thanks for the reply but how can I check it? The only thing I can think of is to take it *all* apart again and put clay in there or something?

How far off do they usually sit and do they pick up from the very rear of the pan or toward the front of the deep part?

 

It sits in the middle of the sump....minimum clearance for pick up tube to pan is 3/8" and no more than 1/2", pretty sure thats the specs but not 100% sure.

Good luck

 

That's good information, I really appreciate the reply!

I think before I take it all apart again I'll take the oil filter off and turn the pump and see how strong it comes out.... It's no more than 1/8" crimped up at the very most toward the front of the pan...

 

Or you could put tow or three quarts of oil in the pan, and connect mechanical gauge..crank a few times and see if the oil psi builds quickly. Which ever way you decide....good luck

 

Well, I finally got everything buttoned up after getting the one broken starter bolt out of the bellhousing and replacing and cleaning up everything. I shorted the fender starter solenoid to crank the motor over a little bit with the oil filter removed and it gushed plenty of oil right away. I put a filter on and with the fuel pump not running I cranked it with the key and watched the gauge. It IS the crappy Ford factory oil pressure switch but it tripped the gauge at 8 psi or whatever it closes at right away on just the starter so I'm not worrying about it. The truck runs great.

Thanks for the good information, it's exactly what I needed.

 

Could you explain tripped the gauge at 8 psi? Was this idleing or just cranking?

 

Edit: reread your question, yes, it was just cranking. I had the dash out too and the fuel pump switch was out so I didn't have fuel (on purpose so I could see if the gauge moved without starting it).

The way I understand the stock idiot gauge setup for '90 and later is that the switch in the side of the block closes at about 8psi and the gauge goes from the bottom to a little over halfway, basically like an idiot light going out.

Yes, I should have put an actual pressure gauge on there but if I'm getting 8psi with just the starter cranking, not even idling, I'm thinking that's probably safe...

That oil pressure sensor is rough to get at, this newer truck has what looks like an oil cooler/heat exhanger between the block and the oil filter and it's in the way. I'd like to put the old style bell shaped oil pressure sender in there but I don't think there's room. That way I could solder across that resistor in the cluster and get a working moving gauge like the older trucks had. The only thing I can think of is to plumb something out further with 1/4" NPT fittings, has anyone done this and remember what lengths they used?

 

I see what your saying.


Why not just opt for a mechanical gauge, they are only what $10-15? later

 

I thought about that too, I actually bought one of the Sunpro ones for my old truck and started putting it on but decided not to once I saw how weak that crappy plastic tubing is, I don't trust it. I wound up doing the
variable sensor/solder across the resistor on the gauge" fix on that truck (4.9 so it fit just fine, I loved that motor) and the factory gauge read right where I expected it to.

I know the factory gauges are not that accurate but at least they give you an idea about what's going on if they're variable.

I was thinking about copper tubing for a mechanical gauge, is that OK or can that break over time too?

 

Not sure about copper tubing.


Good luck

 

We have an '87 F250 4X4 (more like a ... $X$ ...!) w/351W-4V. I was thinking about the same issue. I bought a $20 mechanical gauge to supplement the electric on the dashboard but I was disappointed with the flimsy plastic tubing. I wanted to pipe out from the electric sender near the oil filter and add a tee for the electric sender and connect the mechanical gauge with solid copper tubing. Not much room and I was afraid that vibrations would snap the whole thing off! Any other ideas?