Why did my oil pressure read high 80+for at lease 15sec on start-up after I changed the oil and filter? pre-filled the oil filter. I have changed the filter 6 times before and never had this happen.

 

What year car?

 

I have a 2016 C7R LT4

 

you should never, ever prefill the oil filter. That allows unfiltered oil to go directly into the engine.

 

I always prefill the oil filters that hang in such a manner.
What is wrong with "Unfiltered fresh out of the bottle oil" ?

 

I have always filled the oil filters during an oil change. Clean, New oil needs no filtering. Keeps the oil pressure up when you start. The pressure will settle down to normal levels after you run it a while. Notice the same thing on my old vettes as well.

 

I've always filled the filter up with oil on any car or motorcycle oil I have changed.

 

Yup, been prefilling oil filters since my 58 Ford Galaxy bought in 61. It reduces the time the motor is running without oil on the next startup.

I haven't watched the oil pressure all that much as I am normally watching oil temp on startup but I will. And on my C4 having 80 psi is pretty normal while cold. On my old LS2 having 60+ when cold was normal. Will take a look for you over the next few startups.

 

Never heard that. Let me decide, would I rather have (Door A) 6 oz. of new clean out of the bottle oil go thru my oil system once before it is filtered, or (Door B) no oil for a short time?

Door A, please

 

Your assumption here (and by now, with the responses, you should understand that you're incorrect) is that the oil right from the bottle is somehow less pure than anything the filter has picked up while it's been sitting in its poorly sealed cardboard box.

My money's on the purity of the oil right from the bottle. ;-)

 

Never fill a filter with fresh new oil. Now that's funny. Never wipe the oil drain plug off with a paper towel either. You could get lint in your engine.

 

Thank you, I needed a chuckle today..

 

Yes, that dirty, nasty brand new oil. You'd prefer air to float your bearings?

I've been wrong on stuff before, but I'll cling to this old wives tale a long time until I hear a cogent explanation as to why it could possibly be bad.

You might laugh, but I use lint free rags for that. That's because I didn't want to get lint behind a bearing and change a dimension during assembly, but now it's just what I have on hand in the shop for towels...

 

the answer is in the lab analysis. Just take an oil sample from your fresh bottle and have it run for contaminants. The answer is in the results. The tolerances Caterpillar builds into their Diesel engines is way tight and tougher than any gasoline engine. Cat has run thousands of samples and tells its dealers to Never Ever prefill an oil filter. Go ahead if you like, I'm just telling you what the experts tell it's dealers.

 

What are you talking about? You're saying that new oil is contaminated and that starting a car with zero oil pressure is better than having immediate oil pressure. What do you suggest filling the crankcase with?

 

This is getting interesting :-) here's an old trick I use on my '97 Jeep Wrangler with 226k miles... when I change the oil (6 qts) I use 5qts of oil and 1qt of ATF. It's an old method to scrub the lifters and clean things up. I do that every other oil change and it works great, I also pre-fill the filter... I only do the ATF with that older engine, not any of my other cars. I apologize for this not having to do with a Corvette, but I just thought it was interesting and it does help with the oil pressure.

 

I think where it stems from is the concern that a mechanic will use a contaminated spout or the conditions that exist with bulk oil is really the major concern. Most of today's dealers buy oil in bulk....drums or have storage tanks filled 250 gallons or more at a time, especially with many newer engines using synthetic. Have you ever watched how that's done at a car dealership? It's typically done by someone right out of trade school and sloppy. The point is, your car can handle a dry start if the filter is not prefilled, so why take a contamination chance. I've seen bulk oil samples after being handled where the oil has high dirt contaminated just because of the way it's handled. Hey, if you like prefilling cause you've done it that way since God was a boy, go ahead! I don't and the manufacturer doesn't recommend it.

 

Old wives tale.

What actually happened is people, in a few instances, got a scrap of the aluminum top of the bottle cover into the oil filter. This clogged a small orifice and caused loss of oil pressure and subsequent engine failure whitch Cummings would not cover when they found the aluminum foil.

This factual account is easily found with a simple internet search. Extrapolating that to never prefill your oil filter is absurd. Most everyone understands not to allow crap into the oil poured from the bottle.

Does prefilling make a big difference? Probably not if your engine has not been sitting for awhile. It's like eating chicken soup for a cold, it may not cure you but it won't hurt. Chicken soup could hurt if you mix germs into the pot.

 

Wait a minute, got a Motorhome with a 500 cumming and that filter holds 5 gallons of oil. You had better pre fill per instruction. Hard to believe a cat diesel would not recommend the same.

 

Nice try with your Cummins comment and a piece of the aluminum foil sealer. You responded last, so I'm directing this response to you, but it's equally intended for all. By ALL MEANS, you change the oil and prefill your oil filter to your little heart's content....it's your car and many of the members are reasonably savvy on various components of the Z06, which I don't pretend to be. When I said that prefilling the engine oil filters was dangerous, I meant it, because of 37 years as an executive with Caterpillar being responsible for powertrain performance and longevity. We've spent more money on testing oil filters and examining engine failures and possible connections between the two, than 200 Z06 Corvettes would sell for...at manufacturers list! In your world, the only person that changes your oil is you, who handles that job delicately and properly....no dirty anything touches that "oil out of the bottle"....everything is proper and correct, no drips, the floor is spotlessly cleaned, your rags are spotlessly cleaned and your hands are clean. That's not the real world for owners who pay dealers or gas stations or independents, or God knows who else to do the job...and don't kid yourself, maybe on this Forum changing your own oil is common place, but as far as all higher end automobiles (anything over $75,000), the count here of "oil changers" is small. Changing oil in most shops today is one step over washing cars in that shop....straight forward and fairly simple....right? More mistakes are made and damage inflicted than you can imagine. If you believe that "don't prefill" is BS, or "an old wives tail" or something that I just made up, fine by me....really! I'm just passing on some info that the world's number one heavy equipment company demands of it's dealers and passes on to customers. Do your own thing...