swag

I have a '68 corvette 327 with the 350 hp engine. It has about 47k original miles on it and the engine hasn't been rebuilt.

Would it be a good idea to get the engine oil flushed?

If I do, could I possibly put synthetic oil in after?

Or is this all a bad idea?


Thank you

REELAV8R

Is there a way to flush engine oil?

swag

I was looking online and there's a way to do it with engine cleaner.

Basically put the cleaner in with the oil, run the car for a certain amount of time and then take the oil out and replace with fresh oil.

Big2Bird

Both are a bad idea.

sug

I would change the oil as normal run it for a while and then change again you should be good but dont use synthetic oil .

bashcraft

What makes you think it needs flushed?

NewbVetteGuy

It sounds like you're talking about using SeaFoam and then following up with an oil change....

If so, then that doesn't sound like a bad idea to me...


I thought if you switched to a roller cam you could use non-ZDDP additive oil including appropriate weight synthetics, no? -If so, why not?


Adam

SH-60B

Take off one valve cover to see if theres sludge. You might be able to see well enough with a flashlight through the oil fill hole. But the danger of a flush is if large chunks get lodged in the oil pickup, you lose oil pressure.

gcusmano74

Nah, just change it again after a hundred miles. Don't overthink it.

DUB

and I am curious to your response.

And I will 'say' that I have no problem in using the correct type of synthetic oil for your type of engine....due to it is a flat tappet lifter engine. One again...when it comes to OIL...there are many views on this subject.

And as for an engine cleaner...it really depends on how bad it is.

I have used this product a few times and had no bad effects from it. It is NOT something I generally use...but in a few cases....the owner of the car was willing to take the chance due to it being rather badly sludged up...and it did a good job.

http://www.engine-performance-online...-engine-flush/

DUB

427Hotrod

I would not flush it. Over the years "gunk" helps seal up a 48 year old engine. Those flushes will wash away things and can dry out seals. All that stuff washed away gets pumped through the whole engine until you drain it. Which means that stuff is left all over the motor afterwards. The oil comes out looking as thin as lacquer thinner and black as heck. If an engine is so gummed up it needs flushing...you'd be better off getting an engine hoist and pulling it out to do it right.

I'd stick with whatever oil it's had its whole life...likely non-synthetic. No need to swap now.

JIM

mikem350

I have had good results with hi mileage oils. They have extra detergent and additives to stop seal leaks (maybe) and will clean slowly compared to flush. If it gets black right away, means engine has sludge build up. Change after couple hundred miles.

If you have good hot oil pressure, use a 10W-30. If not, use 10W-40

REELAV8R

Oh, ok, I guess I was thinking along the lines of a transmission fluid type flush.
I did some thing similar to a guy's Diesel engine once. Used diesel in fresh oil to clean his engine since his oil hadn't been changed in a very long time and came out like crude oil consistency. Worked for that.
Not sure I'd want to do it to a good engine unless there were problems that warranted a flush and I felt it might improve those problems.

cv67

fishslayer143

Seafoam in the crankcase IN THE PROPER AMOUNT will clean it thoroughly.. follow directions... and don t believe the myth that synthetics will make it leak... if it doesn t leak now, it wont leak after .. unless it was built with rope gaskets in the 50s ..

427Hotrod

As much as I love synthetics for many applications...I just don't understand the fascination with putting it in old Vette's that get driven minimal miles and never abused. Dino oil got this one through 48 years with no issues.....why spend the money and mess with success? I'd rather see you do 3 oil changes with a "lesser" oil and keep the moisture down and get all the combustion by products out than use expensive synthetics and leave it in there a year or two like many do.

It's like "I gotta do something" thought process? Maybe not....just enjoy the car and fix something that needs fixing. This doesn't seem to be one of them.

JIM

Primoz

Buy lesser oil, put it in, drive gently for couple of miles just to circulate the oil and then change it again and put the proper oil in.
That is what I did, because I didn't know if the previous owner changed oil regularly or not.

7T1vette

I would not put any kind of 'cleaner' or solvent into the oil. That stuff could do damage to old seals, etc. Why chance it?

Putting Sea-Foam in a full tank of fuel is a good idea, however. But, not in the oil system.

Synthetic lubricants are SOOOO much better than dino oil, it would be hard NOT to switch. The downside might be that the seals in the engine will have wear on them and synthetic oil molecules are much smaller than for organic oil. So, the engine might show some leakage where it did not with regular oil. That isn't the fault of synthetic oil....merely because the amount of wear on seals might leak syn oil but not regular oil.

If you give syn oil a try, you will find out if you get leakages you don't want. If not, syn oil is the best thing you can do to extend your engine's useful life.

Jebbysan

I have had good success years ago with Rislone on my high mileage winter rides I frequented in southeast Michigan.....
But the real question is why? Regular oil has plenty of detergent in it....

Jebby

ctmccloskey

I had a JIFFY LUBE flush the engine on my Dad's 1980 Ford pickup with 110K on it. It was full of sludge, just a typical nasty old ford 351. Even the Valve covers were disgusting. The Jiffy Lube guys hooked lines to a oil filter adapter and reverse flowed a very hot lubricant (Kerosene, I suspect) while the engine was off. After 25 minutes or so they gave me back the truck with fresh oil.

The truck never developed any leaks after this cleaning and the motor was virtually Brand new looking inside. No sludge, nothing but shiny metal. The next time I changed the oil at 3000 miles I was shocked that the oil was still clear and looked great. I then did it to my C4 L98 after I bought it, again absolute success. I have never regretted this service being done on either of my cars.

Check to see if you have a Jiffy Lube in your area. I do not use their oil or their filters, I supply those.