does synthetic oil cause leaky gaskets?



does synthetic oil cause leaky gaskets?

Postby grumpyvette » January 12th, 2010, 9:38 am

hey grumpyvette?

as far as synthetic in old cars. does anyone actually have any proof that synthetic oil eats seals or is it one of those wives tale things.



Ive never heard of seals failing due to synthetic oil but I see sealants used dissolve fairly frequently, and while its true that some older formulas of gasket cements were never designed to work with some newer synthetic oils, and many (MECHANICS use the WRONG SEALANTS) and theres a very small chance that some of the synthetic oils with their better ability to seep or penetrate into small cracks that might leak, if you use them, after reading the question, , my first thought was , if you do have an oil leak,its only going to take a couple hours to put a new oil pan gasket and timing cover gasket , and rear main seal on the engine, why not just FIX THE PROBLEM!

IVE GENERALLY HAD THE BEST RESULTS WITH ONE PIECE OILPAN GASKETS AND USING STUDS

http://www.summitracing.com/parts/mor-38360
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http://www.summitracing.com/parts/mor-38350
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read this thread, watch the video

http://redlinedetection.com/pages/video/

viewtopic.php?f=54&t=206&p=1154&hilit=+synthetic+gasket#p1154

viewtopic.php?f=51&t=1718&p=11956&hilit=rear+seal#p11956

viewtopic.php?f=54&t=3084&p=11971&hilit=gasket+synthetic#p11971
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THE LT1 uses different recessed synthetic valve cover gaskets , than the standard first gen SBC cylinder heads

its a fact that some synthetic oils are not compatible with some of the products, used as gasket sealants,
example
the yellow weather strip adhesive many guys use as a gasket cement , on valve cover and oil pan gasket was NEVER intended to work in applications like valve cover gaskets , and oil pans or being exposed to engine heat and engine oil, and if you use it like that it WILL EVENTUALLY LEAK for example ,
youll want to use the BLACK RTV oil proof sealant, pictured below on the upper surface of the oil pan gasket
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because the yellow weather strip adhesive tends to slowly loose its grip and dissolves in some hot synthetic oils over several months time.. its ok to use sparingly on the one piece oil pan gaskets because the gasket and the oil pan flange pressing it against the block rail,not the gunk does the sealing
obviously use of the correct gasket sealant in the application tends to prevent the problem, this is simply avoided by taking the time to read the labels on sealant and follow directions as to correct applications

80 350 OS34510T Felpro
'90 350 OS34500R Felpro

obviously the first step is locating the oil leak source, front seals, rear seals and oil sensors,oil filter adapters are common sources, any leak can be cured IF you know the EXACT SOURCE, and having access to a lift or sturdy jack stands so you can look carefully under the car while it idles is a big help in locating most leaks

viewtopic.php?f=62&t=1430

viewtopic.php?f=51&t=1718&p=4257&hilit=rear+seal#p4257

viewtopic.php?f=54&t=206&p=242#p242

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it may be the gasket OR it may be the gasket cement, or the installation, if you use the yellow weather strip adhesive some guys use your doomed to leaks after awhile as that yellow snot slowly dissolves over time in some oils
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keep in mind theres two front pan gasket thicknesses available

viewtopic.php?f=54&t=206&p=1154&hilit=+synthetic+gasket#p1154

your engine if your using the original pan used the thinner gasket

You first have to clean, and degrease the block with a good engine cleaner, spray gunk, and a local car wash with a wand you can use in the engine compartment is a good place to start, when cleaning off and engine to locate the source of oil leaks,youll want to get it completely clean and get it dry. Chalk dust ,or body talc powder or even baking flour in a squeeze plastic bottle like ketchup is occasionally found in restaurants in ,can catch the beginnings of a leak and really help you spot where it is coming from.

IF ALL ELSE FAILS,
theres kits that use UV dye and special light to locate leaks

http://www.amazon.com/Tracerline-TP8621 ... 487&sr=1-2
Typical leak spots are:

Oil pressure sender
rear main seal
front & rear intake rail seal
oil filter seal
rear cam freeze plug
valve cover breather grommet
bent pan or oil pan gasket
front cover seal
valve cover seal
front crank seal
oil filter adapters
oil filter seals
oil coolers and lines
upper pass engine mount bolt hole (shown above)
fuel pump hole.
A fairly complete list but there are other less common ones .
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STUDS make oil pan gasket installs easier in some cases
keep in mind theres two distinct sbc gasket thicknesses,
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btw be sure its oil your seeing leak, before blaming the engine and not transmission fluid,or brake fluid, because thats obviously going too be a different source
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here you can see the thin line of sealant under the rear main cap, thats sometimes overlooked resulting in a slow drip near the rear main seal



most of those one piece synthetic oil pan gaskets come with instructions saying no gasket cement is needed or recommended, I generally use STUDS installed in the oil pan rail on the block and the stiffening plates listed in the linked info under the oil pan flange and Ive always used a bit of contact cement on only the upper surface of the gaskets, as it and the studs holds the gasket firmly in place while the pans aligned and installed

rear seals come in, rubber, silicon rubber,.Fluoroelastomer, and Viton they all work if properly installed but VITOR usually lasts the longest

http://www.summitracing.com/parts/FEL-BS118291/.. rubber

http://www.summitracing.com/parts/FEL-2909/... Fluoroelastomer,

http://www.summitracing.com/parts/FEL-2900/... Silicone

http://www.summitracing.com/parts/FEL-2918/..viton



I prefer to do the timing cover first but theres no reason not to install the oil pan gasket immediately after the timing cover


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viewtopic.php?f=54&t=206&p=1154&hilit=+synthetic+gasket#p1154

viewtopic.php?f=51&t=1718&p=4257&hilit=rear+seal#p4257

viewtopic.php?f=54&t=2725&p=7076&hilit=gasket+synthetic#p7076


when installing an oil pan gasket its always preferable to install the front timing cover first if possible, as it makes sealing the oil pan to the block with the current one piece synthetic gaskets far easier

the front timing cover seal, that provides the oil seal on the damper as it slides into the cover on the crank snout is pressed in from the front, most guys tap it in with a plastic mallet,after carefully cleaning and repainting the stock cover or buying a new chrome timing chain cover as they are fairly cheap,youll want to be coating the outside edge of the seal with a liquid sealant while the timing cover is supported from the rear on a block of wood,the seals knocked out from the rear with a flat blade screw driver and a small hammer , used at an angle on the inside lip, replace it so the inner seals lip angles in towards the crank not out toward the front damper
BUT most guys simply buy a new cover since they are cheap and don,t bother cleaning the old one if it looks damaged, at $8-$10, for a new cover its hardly worth taking a chance, with the old one if its damaged

http://www.summitracing.com/parts/SUM-G3200/

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IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
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Re: does synthetic oil cause leaky gaskets?

Postby grumpyvette » June 17th, 2011, 9:10 am

these sensors are all potential sources for oil leaks but the two blade sensor on the rear of the block, near the distrib base on the early c4 is a known defective part

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http://www.ecklers.com/corvette-oil-pressure-sender-1985-1987.html

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http://www.ecklers.com/corvette-fuel-pump-switch-oil-pressure-sender-1989-1996.html

Corvette Fuel Pump Switch/Oil Pressure Sender, 1989-1996



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Corvette Oil Pressure Sender, 1985-1987
http://www.ecklers.com/corvette-oil-pressure-sender-1985-1987.html?crosssell=Product_Viewed




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Corvette Oil Temperature Sensor, 1990-1996
http://www.ecklers.com/corvette-oil-temperature-sensor-1990-1996.html
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
grumpyvette

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Re: does synthetic oil cause leaky gaskets?

Postby Randy_W » June 17th, 2011, 11:39 am

I always assumed it didn't eat seals but rather was slicker and older design engines and seals such as gaskets were not as tight as more modern stuff and therefore it got by them rather than damaging them. ;)
Randy
Don't mess with old men, we didn't get that way by being stupid!
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