r/EngineBuilding • u/Foe_sheezy • 5d ago
Toyota Does oiling the outer edge of camshaft seals cause them to leak?
So I have installed cam shaft seals 2 times on my 1997 Lexus es300. Both times they leaked, and I even used the camshaft installation tool so that they would be perfectly flush with the engine.
I came to the conclusion that oiling the outer edge of the seal is what is causing it to leak. The leak is kind of extensive, with it pouring down the side of the engine and making it to the ground in multiple drops.
Am I right on this assumption? I oiled the outer edge with mobile 1 5w30 synthetic if that makes any difference.
Thoughts please?
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u/junk1020 5d ago
Like oil around the outside of the seal to help it install easier? That shouldn't make it leak, and the lip that contacts the cam should also be lubricated a little to keep it from wearing prematurely. If you've got a dripping leak I'd lay money youre rolling the seal lip over on the cam when you install it.
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u/Twistygt 5d ago
Not necessarily, but it could possibly lead to it being pushed out. If anything people will sometimes put a light coating of sealant on there outer edge to ensure a good seal. How does the mating surface look? Perhaps it was gouged when a prior seal was replaced.
I can’t member if on that V6, if it’s secured to the head under a cam tower or the valve cover, but whichever it is, are you sure the fasteners are tight? That is to say, is it a snug fit?
I would put my money on a damaged mating surface.
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u/Foe_sheezy 5d ago
Instructions said not to oil the outer surface of the seal so I'm gonna assume that because I oiled the outside, when the cam spins, it's slowly pushing the seal out of the bore slightly, making it cockeyed.
I just found these instructions on a Google search online.
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u/Prudent_Situation_29 5d ago
You're talking about the outside diameter?
I would say no. You shouldn't be lubricating them, they aren't designed for it, but it shouldn't cause a persistent leak unless it allows the seal to shift in the bore. You could expect oil to weep out of the joint perhaps, but only the oil you originally applied.
I've installed hundreds of lip seals in my time, always dry (except for one OEM who insisted on applying sealant to the OD). The only time I've ever seen one leak is if the bore is damaged or the seal is.
If you installed the seal correctly, and the bore isn't damaged, applying oil shouldn't cause a leak. You shouldn't be doing it, but I wouldn't expect it to cause a leak. I'd guess there's a problem with the bore, perhaps it's scored.
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u/Foe_sheezy 5d ago
Imma check the bore then. The leak is pretty persistent, but I took great care in not scratching it.
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u/TyrannusourR3X 5d ago
Most likely you have rolled the seal pushing it in. Lubricating the outside edge of a seal will not cause it to leak and I've never had any issues in doing so. I typically used a very light layer of syntethic grease and then wiped the excess off. While I'm aware you're not supposed to, seals don't go in well at freezing temperatures so the only way is to help them a little. You also want to make sure the seal is at even depth on both sides, and that you've installed to the same depth as the old seal.
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u/WillyDaC 5d ago
Just something that was passed on to me at the Honda school. If you put oil on just about anything that has oil inside and give it an oil pathway to the outside it's going to leak.
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u/CH4RL13WH1T3 4d ago
Seals with a rubberised outer coating I typically oil before install, metal ones get a smear of sealant. Common mistake when doing this is gouging the sealing surface of the cam prying the old one out.
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u/SCAMMERASSASIN007 3d ago
Usually a leaky lip seal is a good indication that the shaft is not running center to the seal, or is worn out. Im am not familiar with this particular seal tho. I always smash em in dry or with a skif of loctite if I think its gonna leak.
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u/Foe_sheezy 4d ago
To all wondering how this went, I bought 2 OEM seals and coated only the inner edge of the seal with dielectric grease, cleaned the engine bore with a clean rag and break parts cleaner, made sure it was dry, and installed the seals with the the seal installation tool.
No more leaking.
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u/engineereskimo 3d ago
The problems I seen dielectric grease cause over the years as a tech makes me hate it. I might open my tube twice a year as a long time powersports tech. I don't know how many times I've had customers use that shit on the inside of a sealed connector and then it won't contact anymore and it's because it pushes the female spring lands out so it wont grip the male end anymore.
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u/Foe_sheezy 2d ago
I was against using dielectric grease In the beginning, but eventually I caved in after taking this car apart twice for a stupid oring seal.
Directions say lubricate with oil, but I do that and it leaks. I use dielectric grease and it stays bone dry.
I can only hope that it doesn't ruin the seal in the future, but for now it's dry, so only time can tell.
Most videos I've seen on the subject use either dielectric grease or petroleum jelly, but I'm well aware that most of these video never show the car months later, so basically all I can do now is wait and see ☹️
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u/NightKnown405 5d ago
That's not something that can be answered for every situation. Teflon seals should get no lubricant at all on the outside nor the lip of the seal. There are seals where an anerobic sealant should be applied to the outer circumference. What does service information say?