Lubing Gaskets with oil…

ThomasB · 07-31-2012, 02:02 PM

Hi,

I am replacing the throttle bodies of my 911 at the moment and put in new gaskets (OEM Porsche) in the process.

My question is if it is OK to lube the gaskets up before putting them in place. I put the gaskets in some 50W20 and removed the excess oil before mounting them.

A mechanic book I read mentioned that gaskets in general should not be installed completely dry, but now I’m having second thoughts since the throttle body side of the motor is normally not exposed to oil.

Do i have to buy new gaskets or is this an acceptable, maybe even good practice?

This is what I am talking about:

Porsche 911 Intake System - Page 2

Thank you

Thomas

jpnovak · 07-31-2012, 02:56 PM

I use silicone paste on most gaskets. They seal well and don't stick/tear if you have to remove them. Works great on valve covers.

Peter Zimmermann · 07-31-2012, 03:16 PM

Almost all modern technology gaskets are made to be installed dry. If you soak gaskets in oil it will probably cause them to swell up, which will give false torque when the fasteners are tightened. They might never seal correctly. I've always installed chain case gaskets, rocker cover gaskets, intake manifold gaskets, carb base gaskets, etc. dry. I don't even use oil on o-rings, preferring white lithium grease for most applications (thermostat, oil return tubes, camshafts, etc.). I would replace the gaskets.

ThomasB · 08-01-2012, 04:50 AM

Thank you for your input. I removed the throttle bodies again decided to order new gaskets.

Live and learn.

kanadary · 08-01-2012, 05:19 AM

but you all continue to lube the oil filter gasket before install, correct?

Peter Zimmermann · 08-01-2012, 06:37 AM

Quote:

Originally Posted by kanadary

but you all continue to lube the oil filter gasket before install, correct?

That's actually a square cut o-ring made of rubber. A light film of oil on that is a good thing, but I use a smear of Lithium grease, instead of oil, on that as well.

Peter Zimmermann · 08-01-2012, 06:42 AM

Quote:

Originally Posted by ThomasB

Thank you for your input. I removed the throttle bodies again decided to order new gaskets.

Live and learn.

Q-Tips and lacquer thinner or MEK are your friends! About oil on gaskets, I won't even use oil-based solvent for final cleaning of sealing surfaces. I think that you made the right decision!

KTL · 08-01-2012, 08:36 AM

Actually those intake gaskets do occasionally see oil. The oil tank is vented to the intake system and sometimes oil can be spit into the intake quite easily- slight overfill of oil tank or just simply oil vapor.

Not saying I recommend oiling the gaskets. Just saying that they do by nature tend to get oil on them and are intended to be oil resistant.

I like Jamie's idea of silicone paste. Makes for clean removal in the future and lessens the need to use nasty stuff like MEK. That stuff is effective but mucho bad for your health!

ThomasB · 08-01-2012, 10:24 AM

Yes, the gasket material is in fact oil resistant. The material is Reinz AFM30 for the upper gaskets and Reinz AFM38 for the lower ones.

According to the datasheet I’ve found, both materials are rated "resistant" to engine oil on a scale of resistant/somewhat resistant/not resistant.

Still, the manufacturer recommends to always install the gaskets completely dry, so that’s what I will do, although chances are that they would have been ok with the oil on the gaskets.

Better safe than sorry.

PS: our intake gaskets are also resistant to mayonnaise and cocoa butter!

Tippy · 08-01-2012, 10:29 AM

I wouldn't have sweated it and used it but yes, I install gaskets like those dry.

dshepp806 · dshepp806's Garage

DRY!

Doyle

DanielDudley · 08-01-2012, 05:03 PM

I can't speak to your application, but I knew an old engineer out of Rochester who always soaked carburetor gaskets in oil before assembly, he swore that they sealed better and came apart better, to the point that you could reuse them.

I have tried this method, and found it to be effective on paper carb gaskets. My opinion is that if the gasket takes the oil and swells up, it will work. Pete is right though, it is possible to over tighten on a swelled gasket and this can cause trouble, especially warping of the mating surfaces. They have to be tightened down gently, as if you were torquing a head gasket, all together in series, and not too much.

I am not a big fan of the silicone smear, but I know it is done, and I have done it. I prefer blue hylomar on gaskets I don't want to stick, and it does not take much.

Dry gaskets on perfect surfaces is hard to beat, but it can sometimes be a case of horses for courses.