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xrotaryguy · 02-21-2021, 02:48 PM

I have a 1992 Fleetwood Bounder with a 460 with a noisy lifter. It's not noisy all the time but there's not much rhyme or reason to when the noise starts or stops. Except that the oil pressure gauge often (not always) reads high when the lifter gets noisy.

Where does the oil pressure gauge sensor/sender for this year 460 take it's reading? Is there a common blockage point after the sender? Or maybe a pressure regulator or bypass that could be sticky? Seems like high oil pressure would NOT cause a noisy lifter.

I put 10W30 and a new Wix filter on the engine with 1/2 quart of Rislone hoping the noise might be cured. Long shot... And nope.

The coach is parked. I don't want to damage the cam (or anything else if there's a catastrophic failure). The high oil pressure concerns me most. I'd like to address that and see what happens with the lifter noise, then swap the lifters if necessary.

Any advice?

mbridinger · 02-21-2021, 03:02 PM

How many miles? Depending on where you live you could try lighter weight oil. I have used seafoam with success. Yes, in the oil. A couple of ounces.

xrotaryguy · 02-21-2021, 03:07 PM

99k

That's a lot for a motorhome I realize.

I'm in Phoenix Arizona but it's winter right now. I could possibly try some 5W30.

I've had good luck with seafoam as well but only in fuel systems. That was a 1984 Mazda Rx7 with a varnished-up fuel pickup. Worked like magic!

Thanks for the suggestions!

mbridinger · 02-22-2021, 06:55 AM

I live in phx. keep us posted on progress.

George Schweikle · 02-22-2021, 08:30 AM

I have read that some oil pressure gauges don't really indicate true oil pressure - merely show "something" for owners peace of mind. This included Ford but I don't remember what years. There's a thread to this effect on the main forum from a guy who worked for a major manufacturer. He claimed this change was done to eliminate warranty claims from people who didn't know that oil pressure varies with engine RPM.

xrotaryguy · 02-23-2021, 04:24 AM

George,
Correct, mid 90s and later, gradually more and more gauges started receiving their signal from the ecm or whichever computer. Those gauges display whatever value the manufacturer thinks you'll like best. BMW and Mazda Rx7 temperature gauges were notorious for helping owners blow up engines.

Not sure if this gauge works that way or not. I have a bunch of documentation on this motorhome. Maybe it's time for me to see if there's a wiring schematic buried in there somewhere.

I'll keep y'all posted.

Jpony56hd · 02-27-2021, 02:42 AM

The 460 can get readings from two places, 1: On the side of the oil filter housing, usually a sending unit for a factory electrical gage, not the best place as it reads oil pump pressure only. 2: The rear center of the engine block (in the picture it's just to the rear of the clamp on the vacuum hose, looks like a black dot ) that's a line to a mechanical gage, but it could be either. This spot reads the oil pressure after it's gone entirely thru the oiling system and will show the overall condition of the engine. A mechanical with a 260* (or something like that) gage would help see what's going on (Summit make a reasonable priced Good gage). A stock 460 with 5-30wt oil and High oil pressure is strange. Their is a pressure relief valve somewhere in the filter housing that could be acting up. I belong to a forum 460.com, I'll ask and see if anyone can help. I do remember someone ranting about fram filters and 460 a while back.

rcnuts · 02-27-2021, 01:27 PM

I would seriously consider purchasing and installing an aftermarket oil pressure gauge. Get your camper out on the open road and Keep a close eye on it. After almost 100K miles a head job may be in the cards. FYI the speedo and coolant temp gauge pooped out in our older MH. Replaced with high quality aftermarket gauges.

D Gardiner · 02-28-2021, 06:53 PM

Would not drain and add 5W30 unless Ford approved it for your 1992 engine.
You will need to check your engine oil fill cap, or Ford owners manual for that information.

With that said,
- 10w30 is 10 weight when cold and 30 weight when hot.
- 5W30 is 5 weight when cold and 30 weight when hot.

So when the engine is hot, you should have a exact same oil pressure, with 5W30 or 10W30. Only the cold engine oil pressures will be higher.

Agree with Jpony56hd
If the oil pressure valve/s (don't know 460cid Ford used one or two pressure relief valves) If the relief valve is sticking shut, the oil pressure will go through the roof as RPM increases.

Back when I worked on customer cars daily I have run across stuck oil relief valves. The causes ran from worn out plunger bores, worn relief press in washers, or even grooved relief balls or venatic relief plungers.

xrotaryguy · 03-01-2021, 07:41 PM

I wonder if replacing the filter housing would get me a new pressure relief valve. Even if that cures the high pressure issue, it seems odd that a valve would tick when the pressure goes high. Then again, the two issues could be unrelated.

arcaguy · 03-01-2021, 07:56 PM

If you have a restricted oil passage the pressure can be high and the flow low. A lifter may tick from low flow because it doesn't get enough oil to pump up. A mechanic friend of mine swore by "Hapco Engine Concentrate". It appeared and smelled to be some combination of ATF and lacquer thinner. I also have heard of folks that put kerosene in an engine to clean it out. Your call. As a quick check you could take off the oil filler cap and look in the valve cover to see if there is sludge build up. Good luck.

D Gardiner · 03-01-2021, 10:20 PM

Oil pressure relief valves can fail (stick) intermittently, as they wear out.

They can fail in the open position, causing super low oil pressure at idle.
They can fail in the closed position, causing high oil pressure at higher rpm.

Depending on the engine manufacture, and vintage, oil pressure regulators can be inside the engine, on an external housing, in timing covers.

Most engines also have a bypass valve in the oil filter housing boss, to protect engines from clogged oil filters.

A good engine rebuild shop, factory service manuals, and friendly folks online can help you with your specification year 460 Ford engine.

GypsyR · 03-01-2021, 10:22 PM

If you think your engine could benefit from some internal cleaning, you might try adding one quart of regular Mercon/Dexron III transmission fluid to the crankcase. Best done if your oil is a little low anyway and due for a change. But overfilling for a short while won't cause any harm. Road racers commonly race with an extra quart of oil in their engines (for other reasons). Anyway, that kind of ATF can be considered approximately 10 weight oil. So if you're running 10W-30 already....
The deal with such ATF is that it has a LOT of "detergents" in it. The nature of the transmissions it was designed for are such that they need major internal scrubbing. This same stuff can clean up a lot of grunge in your engine. You have to watch it if it's too cruddy though. The ATF will knock it loose and plug your oil filter with it. Safest to assume the filter is going to get plugged in any case and only run the ATF in your oil a couple of hundred miles.
Some people will put diesel or kerosene in their oil. I certainly won't, ever. Both will thin your oil a LOT. Neither has any appreciable detergent capability in them. In fact, I and many other folks will run the occasional quart of transmission fluid through the fuel system of our diesels precisely because it has detergents that diesel fuel is lacking. Or at least has very little of.

Some people have reported similar benefits using Marvel Mystery Oil and other stuff. I won't use any of that. I just use ATF on the very rare occasion I think it might clean up some varnish or something. AND, I have had it to fix a ticking lifter. But, it was an older engine that had suffered from poor maintenance. Also in the long term I have no idea if the fix stuck. But the real world result was that an Olds with about three ticking lifters went to dead quiet ten miles after having a quart added to the oil. (And then the oil changed after.) I, the car owner, and the shop owner were all pretty impressed and not one of us really believed it would help at the beginning. (Oh geez, that was LONG time ago.)

xrotaryguy · 03-02-2021, 06:46 PM

Thanks, guys.

Agreed on the ATF. I used to soak stuck rotary motor apex seals in ATF. Blowing the ATF out the spark plug holes afterward made a nasty mess but it often worked.

I actually run the oil about 1/4" high in my Autocross Corvair (to keep lifters from pumping down of course haha)

I had Rislone in the pan of the 460 for a few hundred miles but it didn't change anything. That doesn't necessarily prove anything though.

I'm leaning toward flaky pressure relief valve combined with a weak lifter.