Ive got a 93 VG max with 236K miles. I noticed my oil leak a few thousand miles ago, and it would only leak a half quart between oil changes. Now at present, sometimes it will leave a small puddle of oil under the car overnight. I checked the stick and I was 2 quarts low yesterday(WOW) I guess the leak is now getting worse. I was wondering if I could get some stop leak and put in there? Just until I can figure out where its coming from, or fix it. Its leaking from near the crankshaft pulley, and around the timing belt lower cover, and looks like the oil pan itself. This is a job that I feel overwhelmed with doing, myself. Ive already got to replace the heater core before it gets too cold. I will be going on vacation soon, So i plan to install the core then, and possibly get the timing belt and leak looked at too.

 

Sounds pretty messy, just out of curiosity have you checked your valve covers? Look around them and see if the VC bolts are tight enough, sometimes they can loosen after a while and then obviously they'll be some seeping of oil. That's usually the first place I start looking on any engine and can be as simple as torquing them down. Yes if that has gone on long enough you will have to replace the gaskets but that is a lot better than a rear main seal and shiit. Good wrenching.

 

For the oil pan you are going to have to jack the car up and have something support the motor (block, jack stand, hoist). From there remove the cross member. Once thats completed remove oil pan bolts in sequence (refer to FSM for sequence). Use a straight edge to check that oil pan mating surface is flat. If not use a rubber mallet and block of wood to flatten it out. Clean off old rtv from mating surfaces and apply new rtv. Reinstall oil pan in reverse sequence from removal. Go in reverse from there. I have the same lil issue but I/m not driving my car yet. Mine is coming from the fact that I don't have the dipstick in now. Not sure if stop a leak works or not.

 

Well I replaced both Valve cover gaskets about 40,000 miles ago, and havent really looked at them since, but I will be replaceing my fuel filter tomarrow with a 300zx one and then I will check and see if the bolts need to be tightened on the valve covers.

 

Sounds like a bigger leak than Stop Leak could manage. Plus, I'd be concerned it would give you a false sense of security and end up accidently causing more damage. I suggest you park the car before you end up having to replace the engine. Front seal is not bad. Worst part is pulling all the belts and timing belt covers (at least for me...easy job, but annoying!). You seem to already understand you might as well replace all that stuff while you're in there....timing belt, tb tensionor, water pump...etc. Depending on mileage on car...you MIGHT want to consider even replacing the oil pump...just something to consider.....especially if you plan to keep the car and there are no other significant issues going on.

I suggest using a strong rope and support the engine with a cherry picker (engine hoist). Run the rope through the motor mounts and back up so there is nothing in your way when you pull the oil pan. If you have a swing set (a-frame for pulling engines) and a ratchet hoist, that would be even better and keep the cherry picker's legs from getting in your way under the car. You can still do it with a cherry picker, but it's easier with those legs gone.

 

So it's your oil pan? I haven't read a confirmation from you but I see that your receiving suggestions on replacing that seal.

 

Especially with aluminum and metal expansion/retraction....and with the natural vibrations of an engine and traveling.....one should always go back and make sure bolts and screws are at spec after doing some work on the car. I know I've rechecked my VG valve covers a few days after replacing the gaskets. I may sometime check them again 6-12 months down the road.

However, I doubt there would appear to be oil leaking from around the crank shaft if either of the valve covers are leaking...plus there would be pretty good amount of smoke from oil getting onto the exhaust manifolds......I think he would know if he were losing that much oil from the top of the engine.

 

I've seen it happen to customers plenty of times and without really smoking. It leaks from all around the VC's and you they think it's something real serious. I'm not saying that's his problem, I just suggested checking there just to make sure it's not. I know he'd rather do those seals instead of the OP.

 

Well I checked all the valve cover bolts, and they were all loose, I had to retighten them all. I will check the oil level in a few days to see if I am still leaking out a good bit, or if it was just that I didnt fill the oil level correctly the last time I did an oil change. But It does seem to be coming from around the front seal area, and the top of the oil pan.

 

I will adamently suggest if you are leaking that amount of oil, REGARDLESS from up top or at the crank....you absolutely should inspect your timing belt. Oil on the belt will cause damage to your timing belt and cause it to prematurely fail.

BTW, be careful not to overtighten the valve cover screws. I don't have my FSM with me, but IIRC, the "torque" setting for these are like 3lbs. I always do them by hand with a large screw driver till they feel just set. Then I go around 3-4 more time to insure they are equally secure. I do NOT "crank down" on them. I've found that personal gauge works for me on valve covers, just be mindful. There is a reason Nissan used screws and not bolts.

 

Just a reminder, once those VC gaskets are saturated in oil they'll probably never seal properly again. They'll probably hold for a while but you already know you have to redo them soon. Sorry to hear that you still think that other seals are probably leaking. Sometimes the VC's leaking can get messy and be very deceiving. Atleast your closer to fixing the problem.

 

Well Its been about a week since I noticed my oil level extremely low. I checked it out this morning and it was still full, So im assuming that even though I have a small leak, the last time I did an oil change, I may not have put the right amount of oil in there from the start, that could explain why I was almost 2 quarts low.

 

So all you did was tighten the VC's and that was it right, good to hear if that's what happened. Do you notice a drip anymore when running the engine?

 

Nah it seems as if the oil level wasnt filled correctly to begin with. Its been 2 weeks or more since I noticed this, but Im not loosing any oil its still full, and thats a sigh of relief! At 238,000 miles, this is the most I have ever driven a car too, but this car is different from the others! Its solidly built, and I know how to fix most stuff, thanks to the ORGG!!! Thanks for everyones help!!

 

Excellent, see what happens if you diagnose issues properly. A automotive shop might have gotten you for some dough for nothing, good work.

 

Yeah you are right, some shops want to charge you just to diagnose your car, and then it may not even be your problem lol. One guy I went to when I first got my car wanted to charge me $40 just to tell me what was the noise near the drive belts, and I left. I checked the level again, just to be sure, and it was still full, not bad for a 17 old car with a quarter of a million miles.

 

Sounds like the Camshaft or crankshaft front seals to me.....better find it cause it could soften that timing belt enough to weaken it and cause it to snap.......