The Stovebolt Site Forums The Shop Area Engine Shop Oil pump trouble...??? 230 motor

I have a 65 chevy c10 longbed stepside with a 230 motor...

I THINK I have a noise coming from my oil pump. the noise is a whirring/woowoooowoo kind of sound, not unlike a water pump noise. the noise showed up about a week ago. I pinpointed the noise using a wooden dowel and it is loudest at the oil pan right next to oil filter, but the noise is the same loudness as I move the dowel across the pan from left to right. I cannot detect the noise with the dowel anywhere else.

One opinion I gathered is that if the pump were going I would not have any oil pressure. Sort of all or nothing. but I DO see oil being delivered to the valve cover (I can see it when I remove the oil filler cap and look in, while running). Also, my oil dummy light IS functioning and not coming on except when I start or stall.

Another said my oil light will only show low LEVEL but not tell me anything about pressure until its too late.

I am wondering if the noise is something else like the engine bearings.

any input, suggestions for diagnosis, and wisdom, is appreciated.

jerry mann

Your idiot light works on a pressure sensor, not on the oil level. I don't know what pressure it comes on at, though. I would add on an oil pressure gauge since I hate idiot lights.

If the noise is loud enough to hear over the noise of a drill motor, you can pull the distributor and turn the oil pump using an old distributor shaft in your drill. And this is a 2:1 ratio, if your drill turns 1000 rpm the pump will be running at an engine speed of 2000 rpm. This will also let you watch the oil distribution to the valve train.

Oil pumps are very reliable, but your engine is getting old. Usually an oil pump will wear due to dirty oil, and the pressure will slowly drop over time. If one of the gears break, you will loose pressure immediately. And they're not that difficult to replace.

Thanks, Fred, for the quick response...and thanks for the great info. I read the shop manual and an oil pressure regulator valve regulates the pressure at about 35 psi at 2000 rpm. but I couldn't find anything about WHEN the idiot light comes on. (I'd like to put a real gauge in...is it possible to keep the idiot light for looks and also have the gauge? Or replace the light with a gauge in the same spot?)

This noise came on very rapidly...over the course of a 15 minute drive at 50 mph. It wasn't making the noise when I started out, and when I got to the exit ramp I could here the whirring sound. Can the oil pump develop a noise and contiue to deliver oil? common sense tells me yes. the manual, in the engine overhaul section, says to inspect the pump gears for wear and shaft looseness in the housing that would cause leakage. So maybe the shaft finally reached its limits.

I like the idea of testing the pump with the distributor removed, instead of just replacing the oil pump good or bad. But I guess I'm nervous never having removed a distributor before. (She is a daily driver for me.)

I've had the truck for 3 years and have changed the oil every 3000 miles. What happened before me is the question...the truck had at LEAST 196K on it when I bought it (maybe 296K???).

One other thing I should mention...About two weeks ago I noticed the "coffe cream" look on the underside of my oil filler cap. I panicked at first, but the dipstick was, and still is, very clean (I just changed the oil on Dec 15 and it still looks clean.) also the engine continues to run as normal as always. I hope its just some moisture working its way out of the crank case (I was missing my dipstick for a few weeks there.) Ahhh, the plot thickens http://www.stovebolt.com/bboard/ubb/icons/icon11.gif ...Anyway...I guess It could be that antifeeze ate my front main bearings...lets hope not.

the weather is supposed to be beautiful today and tomorrow (fri and sat) here and I'd like to do something before we get back to cold and sleet http://www.stovebolt.com/bboard/ubb/icons/icon8.gif

thanks again...This is my first experience with the Stovebolters and its been great so far!

Jerry Mann

ps I'm not sure if I'm using these "message icons" correctly....

Removing the distributor is easy. Take off the cap and turn the engine until the rotor is pointing directly at something like the #3 spark plug. Disconnect the wire and vacuum, then remove the distributor. Now the important part, do NOT turn the engine, so you can drop it back in at the exact same spot.

I'm amazed at the miles on the 230, I never could get one to last that long. Sounds like time for a new oil pump, if not an overhaul.

Here's what I would do. Put in either a can of engine flush or a quart of kerosene. run the engine at idle until it is completely warm, 15-20 minutes, and keep an eye and ear open for problems. Drain the oil, remove the oil pan and pump. I would inspect the pump, but put in a new one anyhow. You will have to remove the distributor to replace the pump. Be sure you clean out the pan and the oil pickup screen. Put it back together, add oil and spin the pump until oil comes out the valvetrain. then put in the distributor and start her.

As for the oil gauge, the easy way is an underdash add-on. My dad's 64 had gauges instead of the idiot lights. His philosophy: "Only an idiot relies on idiot lights."

I think that the presure on the oil switch is about 7 PSI. It sounds to me like the pipe leading From the oil screen to the pump could have come loose, partially broken, or a hole could have appeared especially since it came on suddenly. If any of these hve occured air could be sucked in as well as oil which will cause it to cavitate and make a whirring sound like power stearing pumps when the oil level gets to low and starts sucking air. To check this out put on a presure gauge because it should read a lower presure than it should normally but you will still get oilflow and some presure. There is one more posibility that I just thought of. If a key has sheared off the shaft could be spinning the gear but not as fast as it should which could make a whirring sound but your oil presure would also be reduced significantly.

If this isn't the problem the only other thing in that part of the engine that could make a whiring sound could be a spun main bearing but that sound should get progressively worse fairly quickly. I hope this helps.

PS Timing gears could make a whiring sound but that would be at the front of the engine.

My "oil pump" woes have been resolved... thanks to all who helped out.

Anyway, I think you "Shop Sharks" are gonna kick my old-truckin' arse because I figured out that my "oil pump" noise was actually my ALTERNATOR . (!!!!!!) It was still charging, altho not without faults, but the bearings sounded like tortured marbles.

I feel like a big doofus. But that sound WAS coming RIGHT thru the bottom of the oil pan, right by
the pump. I guess the noise was conducted thru the bracket to the block and on to the pan. I guess
when I listened to the alternator with the dowel, the noise of the "marbles" overpowered any
"whirring/woowoooowoo" noise that was plain to hear from ten feet away or when I touched the
dowel to the bottom of the oil pan.

As soon as me and my helpful buddies unhooked the belt, the noise disappeared. I'm embarrassed,
but happy. I have a great local shop (B&W Auto Electric, Cleveland, Ohio) that rebuilds 'em for $39. (they didn't have time this morning to do mine (saturday) but sold me another they rebuilt for 10%
off the regular $49 price. I am happy. B&W also does starters, while you wait!)

I guess I live up to my title of "Apprentise Wrench Fetcher."

Jerry Mann

Jerry, sounds like you did fine. I spent close to an hour yesterday trouble shooting a low / intermittant voltage only to find that my meter test leads were intermittant! They are test lead hell now! Just be glad you didn't pull the pan, put a new oil pump in, get 'er all buttoned back up again only to start it and have the same stinking noise! Good catch on the alternator.

Wish I had your luck! We've all had moments like that, the 4hr. dragged out shop time, and someone else comes over and points it out in 5 minutes. :p Was curious, is this one of them newer alts? Ones from around late 80's? They were known to have bad rear bearings and make plenty noise when bad. "Cept, you couldn't rebuild them I don't think, sorta a "throw-away". :rolleyes:

Jerry, you can have the gauge and the light. It's an easy fix. Find the oil pressure sending unit and remove it, get a 2 inch piece of pipe, a T fitting and a plug, I believe it is 1/4 inch pipe. Put the pipe in place of the sending unit, put the T on the end of the pipe, put the sending unit in one side of the T and put the pipe plug in the other. reconnect the wire to the sending unit and you are finished.

When I brought my alternator into the shop, the owner and his son immediately recognized it as an old one. The owner said his son rebuilt one of them when he was 15--his first rebuild. They had some code number that they referred to it with. They said they could rebuild it in the lesser part of a morning. Mine was pretty soaked with oil, from my obvious front main seal leak.

Jerry Mann

thanks for the info, Tommy. I figure I wouldn't need the plug if I was putting the light and the gauge in, right? Or maybe I'm missing something...

Anyway, at NAPA they showed me an oil gauge (Stewart-Warner) that actually had a tube that ran oil to the gauge in the cab...I was surprised, but I guess that is as direct a reading as you can get! Would you or anyone else recommend a brand?

I would like to also install an ammeter and temperature gauge. Maybe mount the 3 as a unit just above the steering column. Not too big, and not too modern-looking. Again, it would be nice to still have the hot and cold lights and even the generator light. I love watching the green "cold" light fade out as the engine warms up. Can I have my cake and eat it too?

Thanks, Jerry Mann

Jerry: The S-W gauges and meters are top of the line instruments. You can get them set up as a duo, trio, quad layout. In one of my trucks I have the quad bracket, which is lighted and is very nice. I have the oil pressure, temp, ammeter,
and vacuum gauge, all S-W and lighted and a real nice set. Absolutely worth the investment. $140.00
Have Fun.

Think Chevy!

It's been a long time since I saw that green cold light. Had a 63 Bel Air with one. Wasn't too long after yours when Chevy quit using them. Go for the gauges. Most people put them below the dash to the right of the driver, doesn't take much of a glance to see them.

that "quad" gauge/meter set-up that lights up sounds sweet! Especially with that vacuum gauge, I can think of my grandpa eyeballing his vacuum gauge in his RV as he put the fog to it..."Poor Fuel Economy!" I just hope I can keep the cold light...maybe I can find another port to tap into. Or if I rebuild the engine, tap a new port in by the thermostat.

As a follow up, I am SO VERY happy with my new alternator! (?) sounds weird...but #1, the shop put on an extended pulley that actually allows all three pulleys to LINE UP! This is a bonus! that might be what toasted the bearings in the old alternator. #2, I swear the engine runs better and the lights and accesories are all steadier. I did just regap the points and clean the plugs etc...but whatever, its running good. knock on wood...

Jerry Mann