chrisntam

Long time lurker now needs some help!

Well, crap. Haven't started my '75 olds 88 convertible for a couple of weeks, went to start it this afternoon and the engine was clacking like it shouldn't be. Looked at the oil pressure gauge, no oil pressure. Shut it off fast. Plenty of oil on the dipstick and no leaks underneath.

The 455 engine was rebuilt totally stock about 20 years ago, prolly have less than 10,000 miles on it, never a problem with the engine since the rebuild. I recall putting a melling high volume pump in it back in day.

So what do you suggest I look at first? Pull the distributor and try to prime the oil pump? Maybe a broke rod between the oil pump and the distributor? I saw on another thread that it takes a 5/16" socket to run the oil pump. Engine runs fine, just 0 oil pressure. 0 pressure on the gauge along with noisy lifters/rockers assures me there is no oil pressure.

If the rod is connected (and not broke), but can't get the pump to prime, I assume the oil pan needs to be dropped to look at the pick up tube and pump. Am I on the right track?

Any help or guidance would be appreciated more than you know!

I'll say it again. Crap.

MDchanic

I'd take out the spark plugs and see if you can get any pressure by winging it over with the starter - usually you should get decent pressure after about 10 seconds of cranking.

You might consider plumbing in a different gauge, too, just to be sure.

If nothing that way, then, yes, I'd pull the distributor and spin the oil pump (counterclockwise!) with a 5/16" socket, and see if that brings up any pressure (pull a valve cover and look for oil coming out the rockers just to be certain that the oil pressure gauge isn't wrong).

If no pressure that way, then, yeah, I guess you've got to take a look at the pump.

- Eric

chrisntam

Thanks Eric. I'd be concerned about cranking it more w/ no pressure, I think I'll go ahead and pull the distributor and look there. My gut feeling is something broke when it shouldn't have. That motor's been bullet-proof.

As a side note, I also got done reading the thread about the guy putting his top back together (in the "large car" area), it's nice to have support here, it is appreciated!

Thank you.

oldcutlass

I think your on the right track in pulling the distributor and doing it manually. I would be willing to bet something with the oil pump or pickup. When you rebuilt the engine 20 years ago, did you put another plasti coated timing set in there?

chrisntam

Regarding the cam timing gear, I don't specifically recall, but I highly doubt I would have installed anything other than a steel gear. Back in the day, I used to work at a parts store, so I had time to research and also learned what parts to avoid.

You may be right that it's an "oil pan off" issue. If that's the case, off to the mechanic it goes. I don't have the ability to lift the motor to get the pan off here at the house. Luckily, it crapped out in the garage and not when I was on the highway.

It's funny, as I get older (53), working on them isn't as fun as it used to be. My enjoyment now comes from cruising around top down with the wind going through my thinning hair.

oldcutlass

The other thing you can do is drain and screen your oil to inspect for contamination. Remove and cut open the oil filter and look for the same thing. Reach in the drain hole in the pan with a coat hanger or some soft welding filler rod and see if the pickup may have fallen off the pump.

Crapping out in the garage is very convenient and less stressful.

Hell I just turned 55 and still enjoy working with cars. It's my stress relief.

Good luck with it

matt69olds

Pull the distributor and inspect the oil pump driveshaft. If its intact and the distributor gear and oil pump driveshaft hole isn't stripped (I have never seen that happen, anything is possible) turn the oil pump haft with a 5/16 socket. If you still have no oil pressure dump a couple extra quarts of oil in the pan. If you have oil pressure with extra oil in the pan you know the oil pump pickup has come out of the pump. If you still have no pressure,the pan need to come off to inspect the oil pump.

brandon 455

I had the same problem with my 455 last summer. I drove it to work one day and parked it. Went out that evening to head home and to my surprise my oil pump had quit on me.

MDchanic

And...?

- Eric

chrisntam

Well, I pulled the distributor this afternoon, 100 degrees outside, hooked up two box fans and got after it. Marked how the distributor was oriented, disconnected everything and the hex rod that connects the distributor to the oil pump came right out with the distributor. Evidently, I put it in wrong 20 years ago. I now know the washer is supposed to be between the oil pump and the block (didn't have manual then?)

I duct taped the rod to a 5/16" socket and duct taped the socket to a long extension and put the rod back in. Hooked up the drill and nearly instantly, I felt the load of the oil pump! Had wifey look a the gauge, she says about 60 lbs.

Put it all back together without hooking up the spark plug wires, cranked the motor and got oil pressure. Hooked up the plug wires, it fired right up and got good oil pressure (don't recall the amount).

So...........either I didn't know what the eff I was looking at / hearing when I thought I'd lost oil pressure or I did and now it's fixed. I kinda think choice A is likely the correct one. I just need to throw a timing light on it, drive it and watch the gauge to be sure.

With that, thanks to all who chimed in to assist. Was nervous pulling the distributor and getting it back in right, but only had to move the oil pump rod once slightly for it to fall right back in. Lucky, I guess.

Thanks again and I hope to soon be a contributor instead of one who is needy.

MDchanic

Fantastic! I'm still not completely clear as to what the exact problem was (and I suspect you're not either ),
but it sounds like it's working, so all's well that ends well.

- Eric

oldcutlass

Ok, I'm perplexed also. I guess better safe than sorry. Do you have a mechanical or electric oil pressure gauge setup?

chrisntam

Well, I certainly hope so! I'll just keep an eye on it and hope for the best. Just love driving that car. Top down is the only way to go, except if you're on the highway with lots of other cars going the same direction!

chrisntam

It's mechanical, 270 degree sweep Stewart Warner.

oldcutlass

Wow, that's weird.