Synthetic oil ?

Geo-TH,In · Jan 27, 2012

A man who owns antique cars told me that he put synthetic oil in his old Cadillac and it caused the valve cover gasket, pan gasket and main bearing seals to leak. He claims that synthetic oil is too thin for older engines or there is something in the oil that causes gaskets to leak. Is this true? It doesn't sound right to me.
George

rustred · Jan 27, 2012

sounds crazy to me. a gsk. is a gskt. and if its sealed its sealed. but them old valve covers and pan gskt. were hard to seal so i think he is blaming the oil.

Foghorn Leghorn · Jan 27, 2012

He isn't really understanding what has occured. The gaskets were bad before, but not leaking due to deposits and sludge sealing them from the inside. The synthetic oil removed those deposits and revealed leaking seals. The same thing has occured to me.

oldtanker · Jan 27, 2012

Synthetic oil can be used in older engines but if there are any gaskets or seals that are close to being shot they will leak with synthetics. New selas and gasket will fix that.

Rick

MisterT · Jan 27, 2012

(quoted from post at 16:27:32 01/27/12) He isn't really understanding what has occured. The gaskets were bad before, but not leaking due to deposits and sludge sealing them from the inside. The synthetic oil removed those deposits and revealed leaking seals. The same thing has occured to me.

That is exactly what happened.

dej(Jed) · Jan 27, 2012

(quoted from post at 08:01:25 01/27/12) A man who owns antique cars told me that he put synthetic oil in his old Cadillac and it caused the valve cover gasket, pan gasket and main bearing seals to leak. He claims that synthetic oil is too thin for older engines or there is something in the oil that causes gaskets to leak. Is this true? It doesn't sound right to me.
George

I am an STLE CLS(Cetified Lubrication Specialist). Not blowing my own horn, but I have worked with lubricants and the testing of lubes for well over 30 years now. I actually headed up the yearly API policing testing programs fro several years.I have never heard such an absurd comment. Synthetic lubes are simply molecularly improved lubes. They come in various viscoity grades. I use nothing, but synthetic products.

(fuelsandlubestechnologies.org)

Billy Shafer · Jan 27, 2012

I had the same thing happen to me. When that oil first came out. I changed over to it just to try it out. In two days I had leaks that were not there before.

Eric in IL · Jan 27, 2012

Foghorn, you saved me typing time -- I agree 100%

Dan in North Houston · Jan 27, 2012

I used to work with a chemical / refining engineer. He once told me that the problem was in the additives, not the oil. The additives have an impact on the seals and gaskets, causing them to swell slightly. When you change to a different oil brand, it may have different additives, which may cause the seals to either swell even more or shrink slightly. His advice was to pick a brand of oil and stick with it to avoid such problems.

Billy Shafer · Jan 27, 2012

Can't help what experts say. All I can talk about is what I saw happen. Had the car for several years. Just minor leaks. Changed to Synthetic oil and it leaked all over the place. Only thing that was done to it was the change of oil.

Mike M · Jan 27, 2012

I had a similar problem. The syn oil made them smoke at start up. Likely seeped in past the old valve guide seals easier then reg. thicker oil.
Syn oil is most commonly found in 0 or 5W something so it is thinner to start with. And these were older units.

INCase · Jan 27, 2012

As others mentioned synthetics will clean the motor out and that is the main reason leakages may start. Synthetics, especially ones like AMSOIL's Z-Rod are made for older cars as they have high zinc and extra rust inhibitors as many classics sit for long periods of time.

THere are some of the older "hemp" seals that are not compatible with synthetic oils. Most engines post 1961-2ish do not have this problem.

teddy52food · Jan 27, 2012

What is synthetic oil made from?

greygoat · Jan 27, 2012

I had this happen to me also !!!!
A friend convinced me to "Sell Amzoil" in the 70"s
to "Get the discount". I put it in my own Buick
V-6,and a 74 Ford pickup, with 300 straight 6, a friends International Scout, with a 258 American motors 6, and another friends Ford full size
Bronco, with a 305 V-8.
ALL OF THEM LEAKED OIL AROUND THE ROCKER COVERS
and other places. ALL of them had CORK type
gaskets. I changed oil and filters, flushed engines, and changed oil again. Replaced valve
cover gaskets. Standard 10-30 oil, except for the Bronco, the owners manual said to use 10-40.
No more problems. ALL OF THE ENGINES HAD A
CLEARISH, VASOLINE TYPE SLUDGE IN THE UPPER
ROCKER ARM AREA! I"ll never use Amzoil again, and make it my mission to warn people of the
consequences!

atlarge54 · Jan 27, 2012

What do they run in trucks at UPS and FedEx? What about 18 wheelers? Synthetics may have some good properties, but are they cost effective?

luv2wrench · Jan 27, 2012

Got a 1975 1 ton chevy. Burns oil like crazy. 350 engine. I put my used oil outta my 1997 1 ton chevy that is 10W30 Mobil 1 in it. HEHEHE with no problems. Good way to get rid of my used oil. HA

Dave in GA · Jan 27, 2012

Synthetics are supposed to clean the engine as they go.

Hmmmm. Maybe if I fry my eggs with it, it will clean my frying pans, too!

HenryO · Jan 27, 2012

I have used synthetic oil mostly Syntec, since it came out. I also used it in my 41 Farmall A and 51 Farmall M without any problems. I have it in my 97 Lincoln now and change it every 15000 miles whether it needs it or not. Will add a quart at about 8000 miles. Last change I switched to Mobil 1 for tired motors. Still get the 22 MPG around town and 26 on hiway. I am a believer.

Eric in IL · Jan 27, 2012

When your "friend" signed you up as a dealer, did he happen to mention anything about pyramid schemes or multi-layer marketing? ...Just curious.

RMinVa · Jan 27, 2012

I've seen it happen many times in older engines and you're right on with your comment. Synthetic oil never caused a leak but it will sure clean out an engine and expose leaks. Modern gaskets and O-rings are much better today.

RandyB(MI) · Jan 27, 2012

One explaination that gets through sometimes is this. I you were purchasing a set of bearings (ball-n-cage / roller) would you buy the one with all different size balls/rollers or would you buy the one in which all the balls/rollers were the same size? No brainer as to which one would bear the load the best and last longer. Chemical engineering , like the man in the know said above. (simplified) The lub can be thinner and penetrate better and STILL bear the load better too!

KIP in MX · Jan 27, 2012

We've switched types of synthetics in helicopter gearboxes and had Garlock seals start leaking. The worst is Shell (Royco) 555. MobilJet 1 can also cause seal leaks. The problem has to be the additives.

sammy the RED · Jan 28, 2012

............Synthetics may have some good properties, but are they cost effective?

In a lot of cases, No.

greygoat · Jan 29, 2012

Reply to "EricinIl...Of course I realized later
that Amzoil was a pyramid scheme!

Synthetic oil ?

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