Discuss 302 Oil Leak... Front seal or oil pan gasket? on AllFordMustangs.com, the place for Mustang enthusiasts.
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I have a leak coming from the front of my engine right behind the balancer. I am new to the 302 as I just bought this car. I knew it had a leak when bought it but it's seemed to get worse in a hurry. The seller said it was the oil pan gasket. After wiping everything down real well and then running it in the garage tonite I can't tell if it's coming from the pan gasket or the front seal. The engine was rebuilt at some point and as far as I know it does not have a ton of miles on the rebuild.
Is the front seal prone to going on these engines? What's involved in changing it?
I'm going to change the oil pan gasket first..the one that's in there is the corkboard stuff with sealant. I'm really hoping this is all it is....really don't want to tear into this motor right after buying the car. It only left a couple drips after I test drove it for half an hour and tonite after my wife took it for a spin to put gas in it there was a small puddle after parking it. Problem with a leak right there is it's slinging oil all over everything underneath.
If it is the front seal, the timing cover must be removed to replace it, which is not a disaster, and the timing cover gasket set has a front end piece of the oil pan gasket to replace, I would check the oil pan bolts to see if any are loose, don't over tighten them you could break one off as most are 1/4 inch, if they are not loose, then wipe as much oil off the oil pan and balancer and run it or drive it just a little so you tell where it is leaking, the front seal is probably more prone to leak than the oil pan, also check the pcv if the engine has excessive blow-by of if the pvc is working properly, it can cause higher than normal crankcase pressure and force oil out places it would not normally leak. How many miles are on the engine?
Usually if the leak is at the front end of the oil pan gasket the oil will just trail down the front of the pan and work its way to going under the pan and when you park it will puddle on the ground just below the leak, You are tell us that its slinging oil this is consistence with a oil leak from the front seal. If during the rebuild the timing cover has to be center on the front of the engine, the bolt holes are larger then the bolts and it allows enough play to cause the cover to be off center. If it slightly off center the seal will develop a leak or maybe the seal was damage when it was installed, or it could have been damaged when the damper was installed. Either way I would rather have to change the front seal than having to replace the oil pand gasket which I had to do on my 95gt after it turned over 100.000 miles.
To change the front seal, drain the radiator and remove it along with the electric fan if so equiped, remove the belt on the damper and the belt pully. Remove the damper bolt. Now you need a tool to pull off and later to reinstall the damper, you usally can get one from your local auto parts store that has a loaner tool program. Remove old front seal usally with a flat tip screwdriver or special tool. Install new seal by tapping it in making sure it goes in straight and evenly. Lightly oil the rubber on the seal that will contact the damper, before installing the damper make sure that the inner spring on the seal has not moved, this is very important, the spring keeps seal pressure on the damper's shaft to provide a leak proof seal. Install the damper and all the other parts you removed. Good luck
Thanks for the replies. It sounds like it's consistent with the front seal leaking. I did check the pan bolts and they were all tight. Rex are you saying that if I replace the timing cover it will also replace that front portion of the oil pan gasket?? I'm guessing you don't have to pull the pan to do the timing cover right? Sorry for all the questions... All my experience is with my Toyota Rockcrawler.
My suggestion would be to wait for Rex to get back to you on the gasket question and then start there. I’ve never had to replace the front seal before so I’m not familiar with that process or the gaskets used but that’s probably where your issues lies.
One thing to keep in the back of your mind is something that he also hit on which is “excessive blow by”. When you look at your engine, specifically your valve covers, do you see a hose coming off one of the valve covers and into your carburetor? That should be your PCV valve which draws pressure and combustion bi-products out of the crankcase. Like Rex mentioned, if that’s not working properly then pressure can build up inside your crankcase and cause oil to leak out at weird places. How’s your oil dipstick? Have you noticed any oil leakage from there? That can sometime be another spot of contention when you have a bad PCV valve.
If the Front Seal doesn’t end up being the culprit then we could look further into your PCV and try to diagnose it from there…
You don't have to pull the oil pan, to replace the front oil seal, the timing cover gasket and the piece of the oil pan gasket on the bottom of the timing cover comes in the kit, it's a little tricky to replace but not bad. Do you have any idea how many miles are on the motor? Too much blow-by, or the pcv not working, can cause it to blow oil out the valve covers, front seal, rear seal, dip stick tube, any where on the engine that can leak under pressure, even if these parts are not worn out or bad. Front seals usually leak when the engine has a lot of miles, or the timing cover was not centered when installed, usually the rear seal leaks first. I would check these other things before replacing anything, otherwise you could be wasting time and money and still have the problem. These are great cars but they can have problems, You'll find an abundance of knowledge and experience from these forums. Good Luck.