77 ltd problem

most likely sounds like worn main and/or connecting rod bearings. could be worn oil pump. first thing to do is change oil and filter to make sure everything is clean. knowing mileage and oil change intervals and how its been driven would help to determine the problem.

Does that light go out when engine's at speed?

Sounds like worn bearings, from the idle PSI.. but what is it at operating rpm?

You could and should use a heavier weight oil.. like 20w-50 if such is the case.

The oil pump pickup screen is blocked. Fix it now and you may get several thousand more miles out of that engine.

Rob

Just out of curiosity, how many miles do you have on it? I am the proud owner of a 77 ltd country squire wagon that I inherited from my parents. It has just over 100,000 miles on it. The bulk of that mileage was accumulated on the highway as they only used it in the summer time traveling. The car was never winter driven. I only use it myself in the summer, but I enjoy driving it. It still runs great, and it don't burn any oil. It is hard on gas, but that is to be expected, & I only use premium in it.

Tom probably gave the best cheapest advice to cure the problem. Rob might be right about the sump screen but this is not an easy fix and what usually plugs the screen is the nylon fiber upper timing gear which means more fixing.[but if it chewing up it has to be fixed anyway and wouldn't have too many miles left on it as is] could be someone just put in too light viscosity oil [like 5/30 or thinner]

OK I have to agree with those that have already responded the main and rod bearings are probably toast and I also suspect it has the 351 M /

400 series engine. These were based off the poor oiling 351 C and also were pourly oiled especially the 351 M far more so than the 400! Maintenance of the 351 M is very important in the 3,000 mile range on oil changes as these engines gum up if not properly maintained and the poor oiling becomes No oiling and wipes the bearings. The reason you have oil pressure on start up is the engine is cold once the oil warms up the oil thins and you have the issue that you have.

I would try to change the oil first as well to see if that helps while doing so check to see if there is any gas in the oil as the carbs of this vintage dumped gas into the oil if the power valve stuck. Once the oil mixes with the gas that will also wipe the bearings. If you decide to fix it I would at least suggest at least changing the pump screen and pump when changing the main and rod bearings (may need a crank if this has been going on for a while)! Sorry but if it was mine and you plan on keeping it I would pull it refresh the timing chain boil the block and go straight through it completely!

Just my opinions hope they help

hay nat .the enginge lite might be choke not opening after warm up.it would run rought.as far as oil pressure 2psi motor would knock or be blown up.i had 73 buick 350 with sun oil gage same thing.had car for years never knocked. with gauges you get what u pay for. hope i gave ya acouple things

Seeing as these two engines are identical - except for crank stroke & pistons, both are just as susceptible.

Rob

It is a 400m, the eng light does go out when ya accellerate, putting in the t connect for the oil gauge was a lil tricky! Very limited space to say the least,do have a new sending unit connected, it's at about a lil over 160 k miles, has been a very reliable beast, is hard on gas, doesn't burn oil, has good compression, you can peel out the tires on the street! Have tried to give her tender lovin care, have used lucas in the past, have put in some sea foam crap through the intake a while back, thought that might have helped, have not been driving her, just start her up everyday to pump some air into her, have never taken the oil pan off before, in some books they say it's wise to raise the eng. Is there another way around that other than to take the eng out? Do have a ch picker but don't feel like raisin her up ya know! any thoughts are helpful

as far as pulling pan . if it nessacery or not a little x-tra room not a bad thing for a back yard oil pan drop.disconnect center bolt onengine mount and jack one side of engine.;

As for a rebuild the oilin system is a little oily in the cleveland family any suggestions with a possible modification of the oiling system? A deep sump pan is an idea the question is it worth the hassle..... I'm crazy and willing to try some new things, tried talking to trw but found out they swichted to federal mogul that was awhile back am I right? Guess a 351c piston could work which supposedly bumps the compression to 10:1 do want to rebuild her but need to get some money and knowledge rounded up, any building suggestions? would this be too much for the engine being at 160k? I'm still learning when it comes to an engine so bear with me

A LTD's 351 would be a Windsor.

I used to own a 1977 LTD Landau

mine had a 351M, according to the guy that owned the autparts store where I bought parts at.

one of the best riding cars I have owned..... gas mileage sukked for delivering pizza, though

I had mine from 1987-1991, used it to deliver pizza 2 years, and all I ever did to it was oil and filter changes, tires, and brakes.

K gonna start diagnosing tommorrow, wanna thank you guys for being a help, finally bought most of the bottom end parts yeah! Anyway, doing the oil change tommorrow and will see if going to have to open up a can of worms! Will keep posted, really do appreciate what's been said :)