midyearvette

it could be that the pickup has fallen off, however usually it is noisy as the crank hits the pickup....

MikeM

All this could add up to low oil level in the pan. When you changed the oil six months ago, did you put in 5 quarts or 6 quarts? I have seen a 6 quart pan, low a little over a quart on oil cause your same exact symptoms.

Even if your stick shows full, it could be the wrong one giving you a false reading.

B-52

If you watch your oil pressure gauge under acceleration , which most of us do not, you will see a drop from approx 45 to 30 psi under modest , normal acceleration . . Warm oil. As soon as you stabilize on speed it will return to previous value.
Under full throttle acceleration it will drop more with the higher loads , moving assembly opening up clearances , and yes, possibly the pump scavenging.
If it is now greater than in the past work your way through the recommendations starting with easiest first. Change the oil and filter top off the crankcase.
Try again

Westlotorn

If you are having these issues something is wrong. Oil Pressure goes up with RPM, Oil supply goes up with RPM. Clearance remains the same. You will have more spill, rods, mains, Cam Bearings but spill will equal increase in pressure. A drop means a leak or lack of supply. Possibly the gauge issue. Not a normal function. May be common in these cars but not normal in any engine and could be fatal to your engine. Hope the fix is obvious.

TCracingCA

Not to beat up this particular OP, but I am seeing a trend where guys are jumping onto the forum about problems prior to doing any logical or obvious or needed troubleshooting on their own. Thus us old timers or me expect that some steps to check the problem were taken first and then people go on the forum to get higher end help, but it appears just the opposite.

Here now we have a leak, we have a six quart pan where it was suspected to be a 5 quart. So we don't even know whether the oil level is correct! Changing the oil will be needed automatically based on it just being time to do so, but after some diagnoses. The recommendation with the Rislone, is that you do change the filter and oil after running this product. You don't change the oil and then run it! Also now that we know it is a six quart pan, buy six quarts of oil after the leaks are fixed and most important immediately and I mean immediately after it all runs down to the pan before starting the engine etc., reference where your dipstick reads with a known 6 quarts for sure in it. After pouring it in, I would wait at least a 15-20 minutes after the pour and then check the dipstick level. If the 6 quarts is at a level where there isn't a line, then scribe a new line on the dipstick and put a miniature smilely face or something there. Lastly, I don't recommend over filling an engine, unless you just have to get it home or just need to get it someplace for repair.

I will verify, oil pressure should increase with rpm.

Also I hope this filter isn't so clogged that this is the problem. Thus that would point toward a sludged up motor and maybe the frequency of oil changes or your mechanic should be changed.

Also I see alot of guys just like to waste oil. Thus what if he changes the filter and oil to the correct level and still has the problem. Thus you just wasted oil, unless you are the type inclined to repour oil (but under very certain types of situations, if it is clean etc. it could be put back in). I run synthetics, so changing oil isn't cheap! Also I don't think the Rislone is needed or should be used if you are running synthetcs.

cmdrwill

MikeM

Why didn't you just tell him to run his old oil through a paint strainer, measure it and pour it back in?

daz_au

Of course I intend on doing the basics, but given that the car was fine at the oil level indicated as full on the dipstick last week and is not this week, I am guessing something abnormal is occurring and was looking to the forum for experiences that may have been similar.

I dont like wasting oil either, Penn Grade is $7/qt, but a motor costs more so I am gathering as much information as possible before proceeding with next steps.

MikeM

You have never said whether the oil change six months ago was your first oil change and/or how much oil was put in the engine. I suspect you put in five quarts and that was it?

You want to save money? Ditch the Brad Penn and use Rottella T.

AZDoug

Looks like everything has been covered. in one way or another, but to make a synopisis.

Determine if you have 5 ot 6 quart pan.

Drain oil, and measure it as youadd it back in.

Did you add 5 qts or 6 back in?

Add enough oil, less about 1/2 qt for the filter, so you have 5 quarts total oil including filter for a 5 qt pan and 6qts for a 6 qt pan.


How old is the filter? If more than 3000 miles, change it, and add that 1/2 qt back in to the filter before installing it.

Look at dipstick, does it read full? or something else? If something else, mark the FULL line on the dipstick by scratching it with a file. You can get a correct dipstick or dipstick tube later if you want.

Check to see if problem has gone away.

If problem persists, you need to drop your pan and check the pickup. I had a pickup fall off many years ago, and never noticed it except the oil pressure dropped under braking as the oil sloshed forward, uncovering the pump. You have leaks anyway, so dropping the pan isn't a real burden.

Doug

daz_au

It was my second change on this car. When I bought it I dumped the oil immediately, but used regular 10w30 (which I was later warned off due to low zinc content), so I changed to Penn. On both occasions I :

1) dumped 5QT straight in
2) waited 1/2 hour for it to drop
3) Used 6th bottle to bring to full
4) Started and ran car for 1 min or so
5) Topped to full again.

I check the oil in the car at least once a fortnight and have always maintained the same level (full mark on stick) without issue. I have in car video which allows me to replay the gauges during many drives over this time all with this same oil level and no pressure drop ever. Yet you still seem to think this has something to do with how much oil I put in it 6 mths ago !

JohnZ

I don't. Oil pressure rises with RPM (until the bypass spring opens the valve), as bearing clearances don't increase with RPM, and they are the key contributor to resistance to flow (which creates pressure). If RPM alone causes oil pressure to drop, the issue is on the supply side - either there isn't enough oil, or there is, but the pickup isn't on the pump or the screen is restricted. That's where I'd go first.

MikeM

Don't now since you have confirmed you put six quarts in at the last change. Now, go back and check to see if someone has blocked the filter bypass when you pull the filter off.

daz_au

Will do, I will be all up in there this weekend no doubt. Now preparing myself for pan removal, thought I may as well order a gasket will need one regardless at some stage if not now. Even that isnt straight forward ! Found this post on the forum discussing thin and thick end seals and one piece gaskets with cutouts on BOTH sides for the dipstick !

http://forums.corvetteforum.com/c1-a...t-problem.html

So given I have a '62 327 block with a L76 6 qt pan (driver side dipstick) should I stick with a 4 piece gasket ?

jdk971

daz
i hope it is something simple. remember to use some sealer at the corners when you put
the pan back on. jim

daz_au

Thanks Jim, will do, hope it's simple too. I see you have twin corvettes also, Silver would have been my first choice .

TCracingCA

Just to clarify- by no means should the OP reuse the oil currently in the engine!!!!!!!!!! But alot of the individuals think that the Op should just change a filter and oil and continue traveling down the road. I don't. But if he took that advice from others, then found the problem was still present. Now you have practically new oil that is wasted, because it has to come out again. Thus personal decision as to whether you think it is clean enough to go right back in.

MikeM - You never did return my paint stainers from way back in high school!!!!! Why? And my smile function is down again!

TCracingCA

I still think you should verify the dipstick and oil volume. Actually since you have a cannister and not the spin on, I do need to revise comment (and I am surprised no one caught it). With a spin on, you can pre-fill the filter easily and spin it on (primed). I get creative and do it with the cannister type also, but most don't. Most start the engine to get it all primed and into that cannister.

The lesson I was trying to give, is so that all of us so called experts don't steer you down the wrong advice path, some troubleshooting will help so the advice is valid.

Your own self discovery of the type of pan, tells me that your brain is working. The engine was running well, problem just occurred, thus some here want to guide you to disassembling things to look for things wrong. The fact that the pan is leaking, that should come off more so because of the leak and not necessarily right now because of the symptoms. Thus my advice is to try something super simple (Rislone and check the gauge, dipstick, etc.. It looks like you just indicated the level is down (revised). Prior to that, we all assumed if you were leaking, it is down. Thus put a quart or whatever in and go drive it again! (So we waste a quart or so!). Thus the problem didn't exist at RPM when you last viewed the dipstick, when the level was at the line.!!!!

Matt Gruber

or the pickup fell off.

badgerdog

chek your windage tray, oil may be around crank