Ok so i picked up my 1st car, before my buddie passed he told me there was an oil pressue issue but he had been sick for quite a while and hadnt had the energy to mess with her. When i got the car, it was a rush to get her on the trailer before a storm rolled in. I noticed the oil pressure was at 4psi. The motor was built in 95 and is it had 10k miles on it id be shocked. He had her for 12 years and only rolled 3100 miles on it.

anyway i moved the car further back in the garage this weekend and noted my oil pressure. at first start she was at 25ish psi. then quickly dropped to around 5 then flat lined. I was thinking it may be a bad sender that got warm and would send a false reading, i had a mustang that was bad about that. Well i started looking, and the car has an aftermarket mechanical gauge, so thats not the case.

After a lot of reading last night (Thanks in advance for all the great info here) i was starting to think it was going to be what i was hoping it wasnt, spun bearings. well i came home today with the plan of changing the oil and filter on the slim chance that she may have a clogged filter. well i pulled the stick and checked it out (should have done it from the beginning) Oil is over serviced, watery and smells of fuel.

so here is my question. with a mechanical fuel pump, is this due to a mechanical failure? a gasket failure allowing a bleed by? typically something that will reseal its self from running?

Suggestions? New pump? new gasket? change the oil/filter and keep a close eye on it? send the car to the crusher?

 

Gasoline in the oil suggests seepage past the rings, so an engine overhaul is in order. I don't think a defective mechanical fuel pump could allow fuel to get into the oil.

Water in the fuel could be due to simply the engine being run for only short periods without ever being fully warmed up, so it's just condensation that's never been boiled off, which is an easy thing to remedy. Or it could be a leaking headgasket allowing coolant into the oil, which is a not-so-easy thing to remedy.

Given that you have both fuel and water in the oil, I think you're looking at new rings and headgasket at least, regardless of how many miles it's been since the engine was rebuilt in 1995.

 

Why wouldn't a mechfuel pump not be a suspect. There's only a rubber diaphram between oil and gas inside the pump.

 

That's why I said I don't "think" it's possible. But I'm wrong. My apologies.

 

Please tell us the engine, carburetor and year if possible. The engine may be fine and it could also need work.

If it were mine I would change the oil and filter to a 10W-30 if you live in a very cold climate, otherwise a 15W-40 and check the oil pressure. Oil thinned by fuel will give a lower oil pressure. If it is still low, try another mechanical gauge. If there is any knocking in the engine the bearings are likely worn and running it could worsen the problem. Stop running it at all on bad oil!

About fuel in the oil, it could easily be from many short start-ups without being driven, a bad float in the carburetor, a way overdue oil change or as mentioned a bad fuel pump.

Doing a compression test would also be in order just to learn about its overall condition.

Good luck and please keep us posted...

 

send the car to the crusher?
=================
What, for what?

The obvious place for fuel to get in the oil is where the fuel meets the crankcase- at the fuel pump. They are dirt cheap.

Put on a new FP, change the oil, and bring her up to temp and see how she behaves. Might be good to go for years.

Watery oil might just be condensation.

They WANT to run, give a little help and see if it's easy.

 

fuel pump......

 

watery as in milky (water mixed with oil) watery as in thin (gas mixed with oil)? Hope it is the latter and only due to a bad fuel pump.

 

Fuel pump change, oil and filter, open old filter and look for metal. 15/40 quality oil.
x2 on sugar bears' reasons for fuel

 

X3 on fuel pump may be the issue. I suspect that from your original description of the PO's limited use of the car that he may have started the car occasionally and that it ran a lot with the choke closed for short periods of time. That coupled with not running the car long enough to burn off the moisture and not changing the oil could account for both the fuel and water issues. I would change the oil and see what it does.

 

motor is a 455, car is a 74. I couldnt tell you the year of the block. its not original, but i was about 11 when it was built so im playing catch up on the details on this build. Luckily i have a file with every receipt on the car. carb is a Holly, not sure on the size.

crusher was a joke. my wife would like that, but it was a joke.

i re-read what i put. the oil doesnt appear to have water in it. it is VERY thin. I am going to say the fuel is the reason for this.


sounds like the common thought is the fuel pump. That is what i am thinking also. As far as the car never being run to temp, I really cant comment. I can tell you what i was told.

"the car has low Oil pressure. Im still driving it but not very far, we pretty much stay in town".

That said the town he moved to is maybe a half to 3/4s a mile long and maybe a 1/4 mile wide. The closest town is about a 25 min drive. So i dont know how much driving to temps we had. Part of the fun of getting back into a car and not talking to the previous owner about the actually life of the car.


Im almost tempted to drain the oil, toss a new filter in and drive for for a bit, keeping a close eye on the oil. Other side of me says screw it, just put a new pump on her and give me a good piece of mind.

hopefully i can get a few minutes off work and can pull some plugs, do a compression check, get a good look at the fuel flow from the jets, etc.


oh and find out why i have no brakes lol.....

 

No not fuel pump its carb related I had same issues and it was because of a bad carb rebuild. The needle seat or something is sticking and basically flooding the engine with oil

 

If I pulled the pump would it be pretty obvious if it was bad? Something I could inspect?

 

No not really. Think about it this way... if enough fuel was going thru the carb to dilute the oil... Checking oil pressure at idle would really not be possible as it wouldn't idle. Black smoke out of the exhaust and black fouled plugs.

 

I have no smoke. Running crazy rich but the carb is set up for about 7k feet and now it's in okc... so about 1800feet.

Op at idle is 4 psi at best. Last time I fired her up it spiked to 20 ish then fell off. I'm assuming the oil/fuel separated. As soon as it started mixing it fell off [psi].

I'll check the plugs soon. Unfortunately I have to move the car in the am. I got a nasty gram from my hoa about my boat being in the driveway. I guess the shelby is going to get kicked out of the garage. I really don't want to run the car until it's got clean oil but my hands are tied on this one

 

I came off wrong sorry just stating my experience cause it happened and I changed the carb after a carb guy told me this and no more fuel in oil

 

I had a new out of the box 'Autobone' pump
that went bad and dumped gas in the oil a few years ago.
Good luck with that 74 H/O. More pics when you get the time, nice cars.

 

Sounds like a basket case, PARK IT till you have enough time and some bucks to fix it.


My guess is??
It has a sunk float or stuck needle seat, with leaky well plugs. It's possible the carb could leak all the gas into the motor when it sits, that's about a cup. I would replace the fuel pump for piece of mind and rebuild the carb with a new float.


The oil issue, it was rebuilt10+ years ago, the builder could have missed an oil galley plug, or rebuilt the oil pump and missed something or it came apart. pull the oil filter and cut it apart and look for metal.


The brakes is probally a master cylinder, Don't assume that the new MC you get works, the first new MC I got for my 72 didn't and a friends 68 buick's didn't either.


good luck, take your time and have patience, and have fun doing it, if your not having fun doing it sell it!!!

 

If it is running rich like you say that needs to be figured out as it can have close to the same effect. Albeit it is hard to flow enough fuel thru the carb to dilute 5 quarts of oil and it still run it is possible. Set for 7000 feet would mean it is set lean for us. Less air requires less gas. Basically you have an old car that needs gone thru to find all your problems. None of us can actually see what is going on. It's all a guess.

 

Be advised though if the oil/gas mixture in the sump gets diluted enough an explosion can happen. I would park it till you figure out the problem....My guess is the fuel pump went south but its just a guess from afar...Tedd

 

With enough fuel in the oil to make it thin and watery, my first choice is also a ruptured diaphragm in the fuel pump.
Not uncommon, especially with a car that's not been started for a long time. Rubber diaphragm dries out and cracks.
I know you said it was running rich, but, as was previously mentioned, if it's running rich enough to dump
enough fuel into the cylinders to thin the oil, I wouldn't think it would idle either.
I'm not that up on Holley carbs, but, I know Q'jets are notorious for the plugs in the metering rod wells to leak with age.
Even this would have to be pretty bad to thin the oil.
AN oil and filter change and a new fuel pump is a cheap way too rule out the pump before getting into major work and expense.
The car probably needs both anyhow.

 

So drain the oil and put a new filter on.
It will cost a few bucks, but if the oil pressure improves noticeably then you are probably looking at getting the engine properly tuned rather than dismantling it for a rebuild. Lots of American V8s ran fine with low oil pressure back in the day if the owners didn't beat on them.


Roger.

 

Car is parked. Since I got it back it was pulled on the trailer, off the trailer and into the garage. It's been started once and will be tomorrow for a min.

She's going to be put in the air so I can go over her. I wouldn't call her a basket case but she needs some love. I'll post some pics of the oil and filter when I get her cut open. Like I said I work 7 days a week now so not sure when I'll get a free minute to get to it. With winter coming she will be put to bed for a few months. Give me time to go over everything. I may take the carb to my buddies shop while I'm at it

 

This only applies to the 1966-67 Qjets with the sheet metal plugs in those holes. Later Qjets used a thick, spun-in aluminum plug and do not have this problem. The fuel pump diaphragm is by far the most likely cause of the O.P.'s problem.

 

Well said ol' boy! Any update Vandy? Very curious?

 

Drained the oil, swapped the filter. Fired her up. Oil pressure was better. Sat around 20 then slowly dropped off. I moved the car and checked the oil. There was some fuel in the oil again. Bought a fuel pump. With the new pump installed my op on a cold start was 40 psi +/- then settled to 20psi. It dropped to about 10 for a sec then came back up.

I took the old pump apart. I couldn't see where it was bypassing. Seals where old but not rotted. Next day I get off I'm going to swap my master cylinder (leaking) pull my plugs, check timing, possibly check compression to give me a warm fuzzy and adjust this carb. Do another oil/filter swap and take her for a drive to see how she does.

 

If it is gas in the oil, I would not run the engine for gasoline does not lubricate.
Bearings do not like gas, and won't last long.

Gene

 

Whether or not you can see the cause of the fuel pump leaking, a new one has cured your problem. don't worry too much about not seeing what's wrong, be happy you've fixed it!.
It's not good to run any engine for short periods, the oil won't get hot enough to boil away condensation or gas getting past the rings before the choke came off. Half an hour at normal operating temperature will clear the crankcase of these nasties.


Roger.

 

Good job! Glad to hear it was not as serious as origionally thought! Now you can get out and enjoy the ride.........

 

Getting closer anyway. I need to get my brakes operational. Between work and my free time keeping my dd happy I haven't had a chance to get to the olds. If nothing else she looks pretty sitting in the garage lol