Oil Gurus,I need your opinions

[Colt]

I put around 2000 miles on my '69 vette a year.
Mid April to late Oct.
Been using Amsoil 10w40 synthetic and an Amsoil filter for a couple of years.
Just noticed my rear oil seal has a very slight leak.Nothing on the ground.Just a slight seepage.
I'm thinking going to dino oil will solve that slight leak problem.Preferably a 15w40.
Will dino oil and a quality oil filter be ok going say 2000 miles and changed once a year?
I always change the oil before winter shutdown.

Also if ok what company makes the best 15w40 dino?

 

[sgtgeek]

Yeah the hardest thing on a car is to sit. Seals dry out etc.
Sounds like a seal cracked.....I dunno if oil is your answer so I won't go there....I do not subscribe to putting in a thicker oil to stop a leak.....pretty soon you will be putting in gear lube

I would replace the seal(s) and gaskets while I was at it......as for a good dino oil for the L88 (I assume)....I love the Havoline 10-40....**** fine oil.....but I wouldn't put it in to stop a leak ....just my humble position.....

 

[williar]

I'd recommend Pennzoil High-Mileage 10w30 or 10w40 oil for that vintage of car. The HM oil will help stop the leaks, condition the seals, and reduce oil burnoff. Use the 10w30 if the engine isn't burning oil, otherwise use the 10w40.

I run Pennz 10w30 in my '95 Chevy truck since I only drive about 5K per year, changing oil fall & spring. In your case you could change the HM oil annually. No sense on spending good money on a synthetic for that few annual miles.

 

[Colt]

quote:

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Originally posted by sgtgeek:
Yeah the hardest thing on a car is to sit. Seals dry out etc.
Sounds like a seal cracked.....I dunno if oil is your answer so I won't go there....I do not subscribe to putting in a thicker oil to stop a leak.....pretty soon you will be putting in gear lube

I would replace the seal(s) and gaskets while I was at it......as for a good dino oil for the L88 (I assume)....I love the Havoline 10-40....**** fine oil.....but I wouldn't put it in to stop a leak ....just my humble position.....

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The same thing happened to a friend's '74.
Went back to dino and the leak stopped.
Hope I'm as lucky.
A lot of guys use 20w50 in there old muscle cars.
When I had the engine rebuilt 5 years ago the shop recommended going with a 15w40.
I guess a 10w40 would be ok.


williar
The engine was rebuilt with some mods and only has about 9K miles on her.
High Mileage oil still a good idea?

 

[sgtgeek]

Yeah...it's not the 10- or the 15 you are after anyway...it is the 40

you can try it.....

 

[brian fix]

well the car sits alot and can be hard on seals,also in 69 they used alot of urethane seal material,instead of the newer viton,and others,, you may want to check into a new seal,for lube try a good 5w-40 as Schaeffers,Shell Rotella ,etc,,,as I feel the Amsoil may not be at fault,,,BL

 

[ediamiam]

I also drive a '67 4 cyl Porsche with about 7K on a rebuilt. I use 15w-40 w/ 1 qt of 10w-30 HM oil. Interesting enough, a lot of the guys w/ that engine, even w/ rebuilds, still run w/ a 20w50, Usually because that is what the mechanic uses. The engine was originally spec'd for 30 wt. All the name brand 15w-40 is pretty good stuff - delo 400, shell rotella, mobil delvac.

 

[Steve S]

The Chev. seals will most likely leak They are two piece .

 

[Colt]

Thanks,Guys.
You given me plenty of options.
In the collector car hobby I've heard many times that a slight leak with synthetic oil will stop when switching back to a dino oil.
Something about the molecules are smaller in synthetic oils or something.....
The switch worked for my buddy's '74 vette.When I talked to him last night he mentioned he knew of a few others with chevy blocks that had the same problem and switched and the leak seepage stopped.I hope it works for me.
If not I'll just have to do the fix over nest winter.
As williar mentioned,using synthetic oil for the few annual mileage I drive is a waste of money,so I'll stay with dino oil.
Also was using an Amsoil filter,

Going back to a regular $4-$5 filter.

What auto chains sell Havoline,Pennzoil,Shell Rotella,Mobil Delvac,delo 400...?
I usually buy Mobil1 at Walmart.
been using synthetic oil in all my vehicles for years and never noticed what dino oils are available at Walmart.
I have an AutoZone nearby.
Maybe I'll stop in and see what's available.

 

[ericgl]

First of all, all seals must leak a smidgen to provide lubrication and cooling.
Second, dino oils are not the same today as the old group 1 of 5 years ago. These base oils have low solvency and require the use of seal swell agents to keep seals flexable.
If your convinced the issue is the seal is dryig out, I'd consider an oil with known good seal swell agent like Mobil 1, or try a course of Auto RX.

 

[Colt]

quote:

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Originally posted by ericgl:
First of all, all seals must leak a smidgen to provide lubrication and cooling.
Second, dino oils are not the same today as the old group 1 of 5 years ago. These base oils have low solvency and require the use of seal swell agents to keep seals flexable.
If your convinced the issue is the seal is dryig out, I'd consider an oil with known good seal swell agent like Mobil 1, or try a course of Auto RX.

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Amsoil is in it now.
Wouldn't Amsoil have the same swell agent?
I would think a high mileage oil as williar would maybe have a better seal swell agent.
I guess I'm going to have to experiment.

Then again if "First of all, all seals must leak a smidgen to provide lubrication and cooling"
It may be normal.
In about two weeks I'll get her on a lift and really check things out.

 

[ebaker]

You might consider valvoline Maxlife.