Oil leaking from head gasket

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Mark
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Re: Oil leaking from head gasket

Post by Mark »

marlinh wrote:If that seal is brittle, it is probably worth replacing the whole gasket. It isn't that expensive.
The seal is separate from the valve cover gasket. I changed the valve cover gasket about 2 years ago when I did the valve guide seals so I hope it's still re-useable.
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dlb
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Re: Oil leaking from head gasket

Post by dlb »

i bought a gasket kit from lordco for my wife's old '90 toyota pickup when i did the head gasket on it last year. included in the kit was the valve cover gasket, the 3 donut washer gaskets, and the semicircle things too, so i guess you could just ask for a valve cover gasket set and it would have all those things. or just explain it to the parts people. they should be able to figure it out pretty easily.
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Re: Oil leaking from head gasket

Post by Jarf »

I wouldn't waste time trying to reseal the old donut, they need to be soft and supple to work effectively.
I always get my parts at the dealer as I never have to worry about fitment but aftermarket will work if that is whats available to you.
Some places will sell it all as a kit, others will break every part out separately, as does the dealer.
Regardless, most places will refer to that seal at the back as a "1/2 moon seal".

I would also recommend getting a new VC gasket and the hold down grommets, then you know everything is new and the leaks will be a thing of the past.
A little dab of RTV at the 2 fr "corners" where the cam bearing is and a light smear on the underside of the 1/2 moon will ensure no further leaks, also helps to hold everything in place while you assemble, it is surprisingly easy to displace the 1/2 moon seal during install.

I have re-used VC gaskets and my experience has been hit and miss, so given the price, I always just change them now.
I have also experienced the severely compressed VC gasket (it is easy to over tighten when it is hard and shrunken), it can allow the rockers to hit the cover, learned that one the hard way too, just another reason I replace the gasket whenever I have the cover off.
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dlb
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Re: Oil leaking from head gasket

Post by dlb »

tominMO actually just picked up a fel-pro kit with all the valve cover stuff i mentioned (VC gasket, donuts, half moons). here's his post.

https://tercel4wd.com/forums/viewtopic.php? ... 366#p68056
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Petros
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Re: Oil leaking from head gasket

Post by Petros »

one way to get a leak for sure is to over tighten it. I have also seen cracked valve covers from someone overtightening it, once it is cracked it becomes scrap metal. I have not had a problem ever reusing old valve cover gaskets or the half-moon seal, I just cover all matting surfaces with sealant and than snug it down. if cracked or broken, I would replace it, but even than when I did not have much choice, I have installed broken gaskets with lots of sealant and had no leaks.

It does not take much pressure to seal the valve cover gasket, if you keep tightening it until it "feels" tight, you have likely gone too far, distorted the shape of the valve cover and will almost certainly get leaks where some of surface is no longer sealing. There is a torque value for those cap nuts, but it is not much (in the in-lb range), do it a few times and than feel what it is like with a normal wrench. It will give you an idea of how little they should be tightened.
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Mark
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Re: Oil leaking from head gasket

Post by Mark »

I got the Felpro gasket kit yesterday and replaced all the valve cover gaskets/seals. My old U-seal was hard like plastic. So far it's hard to tell if the new seals have stopped the leak since there's residual oil on the block, but there seems to be less fresh oil around the starter area.
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dlb
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Re: Oil leaking from head gasket

Post by dlb »

i just did my VC and spark plug seals on my corolla. i was surprised how quick and easy a job it was, after figuring out how to remove the spark plug seals anyway.
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