Fluctuating oil pressure

[Manswame]

So I'm not sure if this is even an issue. I'm going to get wood and while driving to the site my oil pressure is fluctuating. While cold its reading about 40 on the dash. After it warms up it drops to 30 while under load but at idle (like at a red light) it goes down to around 15. Is this normal?

Also, battery gauge reads over 13 which I know is normal but one time at a red light (at least one time I noticed) it dropped down to 9ish. I dont think this is normal. Any thoughts?

 

[Preston]

I think it’s all normal lower rpms everything slows down

 

[78C10BigTen]

Its known for sbc to run odd oil pressures, mine does that also.

 

[Arkansas_V8]

Its known for sbc to run odd oil pressures, mine does that also.

Same here

 

[C10MixMaster]

So I'm not sure if this is even an issue. I'm going to get wood and while driving to the site my oil pressure is fluctuating. While cold its reading about 40 on the dash. After it warms up it drops to 30 while under load but at idle (like at a red light) it goes down to around 15. Is this normal?

Also, battery gauge reads over 13 which I know is normal but one time at a red light (at least one time I noticed) it dropped down to 9ish. I dont think this is normal. Any thoughts?

15 on a hot motor isnt bad. low oil pressure on hot idle is a common complaint on a sbc. my motor is getting tired so i installed a hv oil pump trying to buy time. it will start with 60 at idle cold when it gets hot 30-40 on the road 5 or less at idle..

 

[Manswame]

So a little more info. I've been struggling with a sort of stuttering issue under load. I swapped out the spark plugs and the leads. Didnt fix it. Did an oil change and it seemed to have fixed it. Drove into Fairbanks (about 20 miles away) and everything was okay. After getting wood and driving home I was about a mile from home and it started stuttering under load again. Couldnt get it above 30.

I'm kind of at a loss. Any ideas?

 

[DBarre]

So a little more info. I've been struggling with a sort of stuttering issue under load. I swapped out the spark plugs and the leads. Didnt fix it. Did an oil change and it seemed to have fixed it. Drove into Fairbanks (about 20 miles away) and everything was okay. After getting wood and driving home I was about a mile from home and it started stuttering under load again. Couldnt get it above 30.

I'm kind of at a loss. Any ideas?

It could be a fuel issue. Possibly a clogged filter.

 

[Manswame]

It could be a fuel issue. Possibly a clogged filter.

New fuel filter. The symptom disappeared after the oil change (removed almost 7 quarts...way too much) and no is showing back up (checked oil when I got home and was just above "add"). Cant be a coincidence, can it?

 

[73c20jim]

Remove fuel filter
cut open
check inside
Should tell some thing good or bad

PS Have new filter ready to go on.

You can do it with your oil filter as well as long as its been on for a while.

 

[bedwards]

Was your old oil thin and smell like gas? If your making oil, you prob have a bad diaphragm in the fuel pump. That could be your sputtering issue also.

 

[RecklessWOT]

If there's almost 7qts of oil in your engine there is obviously something else getting in there, most likely gas. Pull the dipstick and smell it, easy way to tell (it won't straight up smell like pure gas, but you should be able to notice it, won't just smell like oil either). Gas in the oil will make the oil much thinner, and because it is thinner there will obviously be less pressure. That's why you have more pressure before it warms up, cold oil is normally thicker than warm/hot oil- mix in some gas and now it'll get super thin. Do you have a lot of flooding issues? There are many reasons fuel could be dripping thru your carb down into the engine which will seep past your rings down into the crank case and mix with your oil. I've never been great with carbs but I know a lot of the guys on here are as squares were only fuel injected right at the very end.

 

[Manswame]

Remove fuel filter
cut open
check inside
Should tell some thing good or bad

PS Have new filter ready to go on.

You can do it with your oil filter as well as long as its been on for a while.

I have a several back ups. I'll cut into it when I get home and let you know.

Was your old oil thin and smell like gas? If your making oil, you prob have a bad diaphragm in the fuel pump. That could be your sputtering issue also.

Wasn't thin nor do I remember any noticeable smell of gas. I think the problem was the guy that I bought from overfilled the oil (same dude that zip tied ignition leads to exhaust). One of the spark plugs did have a fuel smell when I took it off.

If there's almost 7qts of oil in your engine there is obviously something else getting in there, most likely gas. Pull the dipstick and smell it, easy way to tell (it won't straight up smell like pure gas, but you should be able to notice it, won't just smell like oil either). Gas in the oil will make the oil much thinner, and because it is thinner there will obviously be less pressure. That's why you have more pressure before it warms up, cold oil is normally thicker than warm/hot oil- mix in some gas and now it'll get super thin. Do you have a lot of flooding issues? There are many reasons fuel could be dripping thru your carb down into the engine which will seep past your rings down into the crank case and mix with your oil. I've never been great with carbs but I know a lot of the guys on here are as squares were only fuel injected right at the very end.

I've been struggling with her sucking air. Replaced all the vacuum lines (most anyway) and fogged them and didnt find anything. I bought a carb rebuild kit so I might just rebuild it and see how many issues that fixed. I'll check the dipstick when I get home.

 

[C10MixMaster]

need to check the fuel pump. if it leaks i can leak into the engine causing thin oil pressure problems etc. fuel pumps are cheep just change it if in doubt.. and change the oil again. you dont want gas in your oil

 

[Manswame]

need to check the fuel pump. if it leaks i can leak into the engine causing thin oil pressure problems etc. fuel pumps are cheep just change it if in doubt.. and change the oil again. you dont want gas in your oil

Fuel pump was already changed out. All in all I've done fuel pump, line from pump to carb, fuel filter, vacuum lines, spark plugs, leads, valve covers, oil change, replaced manifold with headers.

 

[Manswame]

If there's almost 7qts of oil in your engine there is obviously something else getting in there, most likely gas. Pull the dipstick and smell it, easy way to tell (it won't straight up smell like pure gas, but you should be able to notice it, won't just smell like oil either). Gas in the oil will make the oil much thinner, and because it is thinner there will obviously be less pressure. That's why you have more pressure before it warms up, cold oil is normally thicker than warm/hot oil- mix in some gas and now it'll get super thin. Do you have a lot of flooding issues? There are many reasons fuel could be dripping thru your carb down into the engine which will seep past your rings down into the crank case and mix with your oil. I've never been great with carbs but I know a lot of the guys on here are as squares were only fuel injected right at the very end.

As far as I can tell dipstick does not smell like FUEL. Smells like oil. Now that the engine is cool the oil on the dipstick is back at the full level. The oil has normal consistency.

EDITED so I dont sound totally retarded